/* ==========================================================================
   AI Image Resizer — Site Stylesheet (Premium redesign)
   Pure CSS3, no frameworks, no build step.
   Mobile-first. Breakpoints: 640px, 768px, 1024px, 1280px.
   --------------------------------------------------------------------------
   Design language: premium AI-SaaS / creative image tool.
   - Deep "ink" sections (hero, visualization, footer) for contrast
   - Light content sections with soft emerald tints
   - CSS-3D hero visual, glass header, layered depth, controlled glow
   - Reveal-on-scroll system gated behind html.js (content visible w/o JS)
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Design tokens
   -------------------------------------------------------------------------- */
:root {
  /* Brand — emerald/teal system */
  --brand-300: #6ee7b7;
  --brand-400: #34d399;
  --brand-500: #10b981;
  --brand-600: #059669;
  --brand-700: #047857;
  --brand-800: #065f46;
  --teal-400: #2dd4bf;
  --teal-500: #14b8a6;
  --mint: #a7f3d0;

  /* Deep "ink" surfaces (dark sections) */
  --ink-950: #050a08;
  --ink-900: #0a120e;
  --ink-850: #0e1a14;
  --ink-800: #132620;
  --ink-700: #1b332a;

  /* Light surfaces */
  --color-bg: #f7faf8;
  --color-surface: #ffffff;
  --color-bg-subtle: #f0f5f2;
  --color-bg-inset: #e7efea;

  /* Text on light */
  --color-text: #0d1a13;
  --color-text-muted: #46584e;
  --color-text-faint: #64766c;

  /* Text on dark */
  --dark-text: #eef7f1;
  --dark-text-muted: #a9c0b4;
  --dark-text-faint: #82988c;

  /* Borders */
  --color-border: #e0e8e3;
  --color-border-strong: #c8d5cd;
  --dark-border: rgba(255, 255, 255, 0.09);
  --dark-border-strong: rgba(255, 255, 255, 0.16);

  /* Primary + gradients */
  --color-primary: var(--brand-600);
  --color-primary-strong: var(--brand-700);
  --color-primary-soft: #e8faf1;
  --color-primary-border: var(--brand-300);
  --grad-primary: linear-gradient(135deg, #089163 0%, #059669 55%, #047857 100%);
  --grad-bright: linear-gradient(135deg, #34d399 0%, #14b8a6 100%);
  --glow-brand: 0 10px 32px -10px rgba(5, 150, 105, 0.55);
  --glow-brand-soft: 0 6px 24px -10px rgba(5, 150, 105, 0.35);

  /* Status colors */
  --color-danger: #b42323;
  --color-danger-bg: #fef2f2;
  --color-danger-border: #fbcaca;
  --color-success: #047857;
  --color-success-bg: #e8faf1;
  --color-success-border: #a7f3d0;
  --color-warning: #92400e;
  --color-warning-bg: #fffbeb;
  --color-warning-border: #fde68a;

  /* Typography */
  --font-sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas,
    "Liberation Mono", monospace;

  /* Layout */
  --container-width: 1200px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 24px;
  --radius-pill: 999px;
  --shadow-sm: 0 1px 2px rgba(13, 26, 19, 0.05), 0 1px 6px rgba(13, 26, 19, 0.04);
  --shadow-md: 0 6px 20px -6px rgba(13, 26, 19, 0.12);
  --shadow-lg: 0 18px 44px -16px rgba(13, 26, 19, 0.22);
  --shadow-xl: 0 32px 80px -24px rgba(4, 12, 8, 0.45);
  --header-height: 64px;

  /* Motion */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --transition-fast: 160ms ease;
  --transition-base: 260ms var(--ease-out);

  /* Hero 3D tilt (driven by JS, harmless defaults) */
  --tilt-x: 0deg;
  --tilt-y: 0deg;
}

/* --------------------------------------------------------------------------
   2. Reset & base
   -------------------------------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

* {
  margin: 0;
  padding: 0;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  /* Keep anchored headings clear of the sticky header */
  scroll-padding-top: calc(var(--header-height) + 20px);
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--color-text);
  background-color: var(--color-bg);
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  overflow-x: clip;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* Sticky footer: main grows, footer sits at the bottom of short pages */
main {
  flex: 1 0 auto;
  width: 100%;
}

footer.site-footer {
  margin-top: auto;
}

img,
svg,
video {
  max-width: 100%;
  height: auto;
  display: block;
}

h1, h2, h3, h4, h5, h6 {
  line-height: 1.18;
  font-weight: 800;
  letter-spacing: -0.022em;
  color: var(--color-text);
  overflow-wrap: break-word;
}

h1 { font-size: 2rem; letter-spacing: -0.028em; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.15rem; letter-spacing: -0.014em; }
h4 { font-size: 1rem; }

p, ul, ol {
  overflow-wrap: break-word;
}

a {
  color: var(--color-primary);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}

a:hover {
  color: var(--color-primary-strong);
}

ul, ol {
  padding-left: 1.25rem;
}

li + li {
  margin-top: 0.35rem;
}

code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--color-bg-inset);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 0.1em 0.4em;
  overflow-wrap: anywhere;
}

table {
  border-collapse: collapse;
  width: 100%;
}

::selection {
  background: rgba(16, 185, 129, 0.25);
}

/* --------------------------------------------------------------------------
   3. Accessibility helpers
   -------------------------------------------------------------------------- */
.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -56px;
  left: 12px;
  z-index: 300;
  background: var(--brand-700);
  color: #ffffff;
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  font-weight: 700;
  text-decoration: none;
  box-shadow: var(--glow-brand-soft);
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 12px;
  color: #ffffff;
}

/* Visible, consistent focus ring everywhere */
:focus-visible {
  outline: 3px solid var(--brand-500);
  outline-offset: 2px;
  border-radius: 4px;
}

.on-dark :focus-visible,
.section-dark :focus-visible {
  outline-color: var(--brand-400);
}

/* --------------------------------------------------------------------------
   4. Layout primitives
   -------------------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin-inline: auto;
  padding-inline: 1.1rem;
}

.section {
  padding-block: 3.25rem;
}

.section-dark {
  background:
    radial-gradient(52rem 26rem at 12% -20%, rgba(16, 185, 129, 0.14) 0%, transparent 62%),
    radial-gradient(44rem 24rem at 96% 118%, rgba(20, 184, 166, 0.1) 0%, transparent 58%),
    var(--ink-900);
  color: var(--dark-text-muted);
  position: relative;
}

.section-dark::before {
  /* faint pixel grid */
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.028) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.028) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(70% 70% at 50% 40%, #000 30%, transparent 100%);
  -webkit-mask-image: radial-gradient(70% 70% at 50% 40%, #000 30%, transparent 100%);
  pointer-events: none;
}

.section-dark > .container {
  position: relative;
}

.section-dark h2,
.section-dark h3 {
  color: var(--dark-text);
}

.section-alt {
  background:
    radial-gradient(46rem 20rem at 108% -12%, rgba(16, 185, 129, 0.07) 0%, transparent 60%),
    linear-gradient(180deg, var(--color-bg-subtle) 0%, var(--color-bg) 100%);
  border-block: 1px solid var(--color-border);
}

.section-header {
  max-width: 740px;
  margin: 0 auto 2.25rem;
  text-align: center;
}

.section-header p {
  color: var(--color-text-muted);
  margin-top: 0.65rem;
  font-size: 1.03rem;
}

.section-dark .section-header p {
  color: var(--dark-text-muted);
}

.section-title {
  margin-bottom: 0;
  font-size: clamp(1.55rem, 3.2vw, 2.1rem);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--brand-600);
  margin-bottom: 0.7rem;
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 2px;
  border-radius: 2px;
  background: var(--grad-bright);
}

.section-dark .eyebrow {
  color: var(--brand-300);
}

.text-gradient {
  background: linear-gradient(100deg, var(--brand-400) 0%, var(--teal-400) 90%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* Subtle dot texture for light sections (attach to any container) */
.bg-dots {
  background-image: radial-gradient(rgba(5, 150, 105, 0.08) 1px, transparent 1px);
  background-size: 22px 22px;
}

.text-center { text-align: center; }
.mt-2 { margin-top: 0.5rem; }
.mt-4 { margin-top: 1rem; }
.mt-6 { margin-top: 1.5rem; }
.mb-4 { margin-bottom: 1rem; }

/* Responsive visibility helpers */
.desktop-only {
  display: none !important;
}

@media (min-width: 1024px) {
  .desktop-only {
    display: inline-flex !important;
  }
}

/* Pull the tool window up over the dark hero edge */
.tool-overlap {
  margin-top: 0;
}

@media (min-width: 768px) {
  .tool-overlap {
    margin-top: -3.4rem;
  }
}

/* --------------------------------------------------------------------------
   5. Buttons
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.68rem 1.35rem;
  min-height: 44px;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 700;
  line-height: 1.2;
  text-align: center;
  text-decoration: none;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color var(--transition-fast), color var(--transition-fast),
    border-color var(--transition-fast), box-shadow var(--transition-base),
    transform var(--transition-base), filter var(--transition-fast);
  user-select: none;
  white-space: nowrap;
}

.btn:disabled,
.btn[aria-disabled="true"] {
  opacity: 0.55;
  cursor: not-allowed;
  transform: none !important;
}

.btn:active:not(:disabled) {
  transform: translateY(1px) scale(0.99);
}

.btn-primary {
  background: var(--grad-primary);
  color: #ffffff;
  box-shadow: var(--glow-brand-soft);
}

.btn-primary:hover:not(:disabled) {
  color: #ffffff;
  box-shadow: var(--glow-brand);
  transform: translateY(-2px);
  filter: brightness(1.05);
}

.btn-secondary {
  background: var(--color-surface);
  color: var(--color-text);
  border-color: var(--color-border-strong);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--color-surface);
  border-color: var(--brand-500);
  color: var(--brand-700);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-ghost {
  background: transparent;
  color: var(--brand-700);
  border-color: var(--brand-300);
}

.btn-ghost:hover:not(:disabled) {
  background: var(--color-primary-soft);
  color: var(--brand-800);
  border-color: var(--brand-400);
  transform: translateY(-2px);
}

.btn-danger-ghost {
  background: transparent;
  color: var(--color-danger);
  border-color: var(--color-danger-border);
}

.btn-danger-ghost:hover:not(:disabled) {
  background: var(--color-danger-bg);
}

/* Dark-section button variants */
.btn-light {
  background: #ffffff;
  color: var(--brand-800);
  box-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
}

.btn-light:hover:not(:disabled) {
  color: var(--brand-800);
  transform: translateY(-2px);
  box-shadow: 0 16px 40px -12px rgba(0, 0, 0, 0.55);
}

.btn-outline-dark {
  background: rgba(255, 255, 255, 0.04);
  color: var(--dark-text);
  border-color: var(--dark-border-strong);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}

.btn-outline-dark:hover:not(:disabled) {
  background: rgba(255, 255, 255, 0.09);
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.3);
  transform: translateY(-2px);
}

.btn-lg {
  padding: 0.9rem 1.9rem;
  font-size: 1.05rem;
  border-radius: 14px;
}

.btn-sm {
  padding: 0.42rem 0.9rem;
  min-height: 36px;
  font-size: 0.875rem;
}

.btn-block {
  width: 100%;
}

/* Very narrow screens: let long button labels wrap instead of overflowing */
@media (max-width: 400px) {
  .btn {
    white-space: normal;
  }

  .btn-lg {
    padding: 0.8rem 1.25rem;
  }
}

/* Button busy state (tool resize button) */
.btn .btn-spinner {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  border: 2.5px solid rgba(255, 255, 255, 0.35);
  border-top-color: #ffffff;
  animation: spin 0.7s linear infinite;
  display: none;
  flex: 0 0 auto;
}

.btn.is-loading .btn-spinner {
  display: inline-block;
}

.btn.is-loading {
  pointer-events: none;
}

/* --------------------------------------------------------------------------
   6. Header & navigation
   -------------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(252, 254, 253, 0.82);
  -webkit-backdrop-filter: blur(14px) saturate(1.5);
  backdrop-filter: blur(14px) saturate(1.5);
  border-bottom: 1px solid rgba(13, 26, 19, 0.08);
  transition: background-color 0.3s ease, box-shadow 0.3s ease,
    border-color 0.3s ease;
}

.site-header.is-scrolled {
  background: rgba(252, 254, 253, 0.94);
  box-shadow: 0 10px 32px -18px rgba(4, 12, 8, 0.35);
  border-bottom-color: rgba(13, 26, 19, 0.1);
}

.site-header.nav-open {
  background: #fcfefd;
  box-shadow: none;
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  min-height: var(--header-height);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 800;
  font-size: 1.06rem;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.015em;
  margin-right: auto;
}

.brand:hover { color: var(--color-text); }

.brand-mark {
  flex: 0 0 auto;
  width: 36px;
  height: 36px;
  filter: drop-shadow(0 4px 10px rgba(5, 150, 105, 0.35));
  transition: transform var(--transition-base);
}

.brand:hover .brand-mark {
  transform: rotate(-4deg) scale(1.04);
}

.brand-name span {
  color: var(--brand-600);
}

/* Desktop nav (hidden on mobile by default) */
.main-nav {
  display: none;
}

.main-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
  gap: 0.15rem;
}

.main-nav a {
  display: block;
  padding: 0.5rem 0.75rem;
  color: var(--color-text-muted);
  font-weight: 600;
  font-size: 0.92rem;
  text-decoration: none;
  border-radius: var(--radius-sm);
  white-space: nowrap;
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.main-nav a:hover,
.main-nav a:focus-visible {
  color: var(--color-text);
  background: var(--color-bg-inset);
}

.main-nav a[aria-current="page"] {
  color: var(--brand-700);
  background: var(--color-primary-soft);
}

.header-cta {
  display: none;
}

/* Hamburger button */
.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: transparent;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-md);
  cursor: pointer;
  color: var(--color-text);
  transition: background-color var(--transition-fast), border-color var(--transition-fast),
    transform var(--transition-fast);
}

.nav-toggle:hover {
  background: var(--color-bg-inset);
  border-color: var(--brand-400);
}

.nav-toggle:active {
  transform: scale(0.94);
}

.nav-toggle .icon-close { display: none; }

.nav-toggle[aria-expanded="true"] .icon-open { display: none; }
.nav-toggle[aria-expanded="true"] .icon-close { display: block; }

/* Mobile nav panel — app-like animated dropdown */
.nav-panel {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: #fcfefd;
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  transform: translateY(-10px);
  visibility: hidden;
  transition: opacity 0.26s ease, transform 0.26s var(--ease-out),
    visibility 0s linear 0.26s;
  max-height: calc(100dvh - var(--header-height));
  overflow-y: auto;
}

.nav-panel.open {
  opacity: 1;
  transform: translateY(0);
  visibility: visible;
  transition-delay: 0s;
}

.nav-panel ul {
  list-style: none;
  margin: 0;
  padding: 0.6rem 1rem 0.75rem;
}

.nav-panel li {
  opacity: 0;
  transform: translateY(-6px);
  transition: opacity 0.3s ease, transform 0.3s var(--ease-out);
}

.nav-panel.open li {
  opacity: 1;
  transform: translateY(0);
}

.nav-panel.open li:nth-child(1) { transition-delay: 0.02s; }
.nav-panel.open li:nth-child(2) { transition-delay: 0.05s; }
.nav-panel.open li:nth-child(3) { transition-delay: 0.08s; }
.nav-panel.open li:nth-child(4) { transition-delay: 0.11s; }
.nav-panel.open li:nth-child(5) { transition-delay: 0.14s; }
.nav-panel.open li:nth-child(6) { transition-delay: 0.17s; }
.nav-panel.open li:nth-child(7) { transition-delay: 0.2s; }
.nav-panel.open li:nth-child(8) { transition-delay: 0.23s; }

.nav-panel a {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.85rem 0.8rem;
  font-weight: 700;
  font-size: 1.02rem;
  color: var(--color-text);
  text-decoration: none;
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.nav-panel a:hover,
.nav-panel a[aria-current="page"] {
  color: var(--brand-700);
  background: var(--color-primary-soft);
}

.nav-panel .nav-panel-cta {
  margin: 0.35rem 1rem 1rem;
  width: auto;
  justify-content: center;
}

/* --------------------------------------------------------------------------
   7. Hero (dark premium) + 3D visual
   -------------------------------------------------------------------------- */
.hero {
  position: relative;
  padding-block: 3.5rem 4rem;
  background:
    radial-gradient(58rem 30rem at 82% -12%, rgba(16, 185, 129, 0.2) 0%, transparent 62%),
    radial-gradient(40rem 24rem at -8% 112%, rgba(20, 184, 166, 0.13) 0%, transparent 58%),
    var(--ink-950);
  color: var(--dark-text-muted);
  border-bottom: 1px solid var(--dark-border);
  overflow: hidden;
}

.hero::before {
  /* faint pixel grid, fading out radially */
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 42px 42px;
  mask-image: radial-gradient(75% 80% at 50% 30%, #000 25%, transparent 100%);
  -webkit-mask-image: radial-gradient(75% 80% at 50% 30%, #000 25%, transparent 100%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  display: grid;
  gap: 3rem;
  align-items: center;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--brand-300);
  background: rgba(16, 185, 129, 0.09);
  border: 1px solid rgba(110, 231, 183, 0.28);
  padding: 0.42rem 0.95rem;
  border-radius: var(--radius-pill);
  margin-bottom: 1.15rem;
  box-shadow: inset 0 0 18px rgba(16, 185, 129, 0.08);
}

.hero-eyebrow::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--brand-400);
  box-shadow: 0 0 0 0 rgba(52, 211, 153, 0.5);
  animation: pulse-dot 2.6s ease-out infinite;
}

@keyframes pulse-dot {
  0% { box-shadow: 0 0 0 0 rgba(52, 211, 153, 0.45); }
  70% { box-shadow: 0 0 0 9px rgba(52, 211, 153, 0); }
  100% { box-shadow: 0 0 0 0 rgba(52, 211, 153, 0); }
}

.hero h1 {
  color: #ffffff;
  font-size: clamp(2.35rem, 6.2vw, 3.9rem);
  font-weight: 800;
  letter-spacing: -0.034em;
  line-height: 1.06;
  margin-bottom: 1.1rem;
}

.hero h1 .h1-sub {
  display: block;
  font-size: 0.52em;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.18;
  margin-top: 0.5rem;
  color: var(--dark-text);
}

.hero-lede {
  font-size: 1.1rem;
  color: var(--dark-text-muted);
  max-width: 34.5rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-top: 1.75rem;
}

.hero-points {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem 1.35rem;
  margin-top: 1.6rem;
  padding: 0;
  list-style: none;
}

.hero-points li {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--dark-text-muted);
  margin: 0;
}

.hero-points .check {
  color: var(--brand-400);
  flex: 0 0 auto;
}

/* ----- 3D hero visual ----- */
.hero-visual {
  position: relative;
  width: 100%;
  max-width: 560px;
  margin-inline: auto;
  min-height: 420px;
  perspective: 1200px;
}

.hv-scene {
  position: relative;
  width: 100%;
  height: 420px;
  transform-style: preserve-3d;
  transform: rotateX(calc(6deg + var(--tilt-y))) rotateY(calc(-13deg + var(--tilt-x)));
  transition: transform 0.5s var(--ease-out);
  animation: hv-float 7s ease-in-out infinite;
}

@keyframes hv-float {
  0%, 100% { translate: 0 0; }
  50% { translate: 0 -9px; }
}

.hv-glow {
  position: absolute;
  inset: 12% 6%;
  background:
    radial-gradient(46% 42% at 38% 42%, rgba(16, 185, 129, 0.34) 0%, transparent 70%),
    radial-gradient(34% 34% at 78% 72%, rgba(20, 184, 166, 0.25) 0%, transparent 70%);
  filter: blur(8px);
  transform: translateZ(-80px);
  animation: hv-glow-pulse 5.5s ease-in-out infinite;
}

@keyframes hv-glow-pulse {
  0%, 100% { opacity: 0.75; }
  50% { opacity: 1; }
}

/* Floating image card (3D object) */
.hv-card {
  position: absolute;
  margin: 0;
  border-radius: var(--radius-lg);
  background: linear-gradient(180deg, #10201a 0%, #0b1512 100%);
  border: 1px solid var(--dark-border-strong);
  box-shadow:
    -24px 34px 60px -22px rgba(0, 0, 0, 0.65),
    0 0 0 1px rgba(52, 211, 153, 0.06) inset;
  transform-style: preserve-3d;
}

.hv-card-main {
  top: 8%;
  left: 4%;
  width: 62%;
  aspect-ratio: 4 / 3;
  padding: 10px;
  transform: translateZ(46px);
}

.hv-card-result {
  right: 0%;
  bottom: 4%;
  width: 38%;
  aspect-ratio: 4 / 3;
  padding: 7px;
  transform: translateZ(24px);
}

.hv-photo {
  width: 100%;
  height: 100%;
  border-radius: calc(var(--radius-lg) - 6px);
  overflow: hidden;
  position: relative;
}

.hv-photo svg {
  width: 100%;
  height: 100%;
  display: block;
}

/* Resize handles on the main card */
.hv-handle {
  position: absolute;
  width: 13px;
  height: 13px;
  background: #ffffff;
  border: 2.5px solid var(--brand-500);
  border-radius: 3px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.45), 0 0 12px rgba(16, 185, 129, 0.5);
  transform: translateZ(58px);
  animation: hv-handle-pulse 3.2s ease-in-out infinite;
}

@keyframes hv-handle-pulse {
  0%, 100% { box-shadow: 0 2px 8px rgba(0, 0, 0, 0.45), 0 0 10px rgba(16, 185, 129, 0.4); }
  50% { box-shadow: 0 2px 8px rgba(0, 0, 0, 0.45), 0 0 18px rgba(16, 185, 129, 0.85); }
}

.hv-h-tl { top: -7px; left: -7px; }
.hv-h-tr { top: -7px; right: -7px; }
.hv-h-bl { bottom: -7px; left: -7px; }
.hv-h-br { bottom: -7px; right: -7px; }

/* Dimension rulers */
.hv-ruler {
  position: absolute;
  display: flex;
  align-items: center;
  justify-content: center;
  transform: translateZ(56px);
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  color: var(--brand-300);
}

.hv-ruler-w {
  left: 0;
  right: 0;
  bottom: -26px;
  height: 14px;
}

.hv-ruler-w::before {
  content: "";
  position: absolute;
  left: 4px;
  right: 4px;
  top: 50%;
  height: 1.5px;
  background: linear-gradient(90deg, transparent, rgba(110, 231, 183, 0.7), transparent);
}

.hv-ruler-h {
  top: 0;
  bottom: 0;
  left: -26px;
  width: 14px;
}

.hv-ruler-h::before {
  content: "";
  position: absolute;
  top: 4px;
  bottom: 4px;
  left: 50%;
  width: 1.5px;
  background: linear-gradient(180deg, transparent, rgba(110, 231, 183, 0.7), transparent);
}

/* Dimension badges */
.hv-badge {
  position: absolute;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.34rem 0.7rem;
  border-radius: var(--radius-pill);
  font-size: 0.78rem;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
  white-space: nowrap;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.hv-badge-src {
  top: -16px;
  right: -14px;
  color: #d9fbe9;
  background: rgba(6, 95, 70, 0.55);
  border: 1px solid rgba(110, 231, 183, 0.45);
  box-shadow: 0 10px 26px -8px rgba(0, 0, 0, 0.6);
  transform: translateZ(70px);
  animation: hv-float-badge 5s ease-in-out infinite;
}

.hv-badge-out {
  top: -15px;
  left: 50%;
  color: var(--brand-800);
  background: linear-gradient(135deg, var(--brand-300), var(--teal-400));
  border: 1px solid rgba(255, 255, 255, 0.5);
  box-shadow: 0 10px 26px -8px rgba(20, 184, 166, 0.55);
  transform: translateX(-50%) translateZ(52px);
  animation: hv-float-badge 5s ease-in-out 1.2s infinite;
}

@keyframes hv-float-badge {
  0%, 100% { margin-top: 0; }
  50% { margin-top: -7px; }
}

/* Animated resize arrow between cards */
.hv-arrow {
  position: absolute;
  top: 46%;
  left: 47%;
  width: 30%;
  transform: translateZ(34px);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.hv-arrow svg {
  width: 100%;
  height: 26px;
  overflow: visible;
}

.hv-arrow .hv-arrow-line {
  stroke-dasharray: 14 10;
  animation: hv-dash 1.4s linear infinite;
}

@keyframes hv-dash {
  to { stroke-dashoffset: -24; }
}

.hv-arrow .hv-arrow-head {
  animation: hv-nudge 1.4s ease-in-out infinite;
}

@keyframes hv-nudge {
  0%, 100% { transform: translateX(0); }
  50% { transform: translateX(4px); }
}

/* Format chips */
.hv-chip {
  position: absolute;
  padding: 0.36rem 0.8rem;
  border-radius: var(--radius-pill);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  color: var(--dark-text);
  background: rgba(19, 38, 32, 0.82);
  border: 1px solid var(--dark-border-strong);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  box-shadow: 0 12px 26px -10px rgba(0, 0, 0, 0.6);
  transform: translateZ(64px);
}

.hv-chip-jpg { top: 4%; right: 6%; animation: hv-float-badge 4.4s ease-in-out 0.4s infinite; }
.hv-chip-png { top: 17%; right: -3%; animation: hv-float-badge 5.2s ease-in-out 1.6s infinite; }
.hv-chip-webp { bottom: 1%; left: 10%; animation: hv-float-badge 4.8s ease-in-out 0.9s infinite; }

/* --------------------------------------------------------------------------
   8. Cards, grids & feature blocks
   -------------------------------------------------------------------------- */
.grid {
  display: grid;
  gap: 1.1rem;
}

.card {
  position: relative;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.6rem;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-base), transform var(--transition-base),
    border-color var(--transition-base);
  min-width: 0;
  overflow: hidden;
}

.card::after {
  /* soft top glow revealed on hover */
  content: "";
  position: absolute;
  inset: -40% -20% auto;
  height: 70%;
  background: radial-gradient(50% 60% at 50% 0%, rgba(16, 185, 129, 0.1) 0%, transparent 70%);
  opacity: 0;
  transition: opacity var(--transition-base);
  pointer-events: none;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--brand-300);
}

.card:hover::after {
  opacity: 1;
}

.card-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  border-radius: 14px;
  background: linear-gradient(135deg, var(--color-primary-soft), #dcf5e9);
  border: 1px solid var(--color-primary-border);
  color: var(--brand-700);
  margin-bottom: 1rem;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.card:hover .card-icon {
  transform: translateY(-3px) scale(1.05);
  box-shadow: 0 8px 18px -8px rgba(5, 150, 105, 0.45);
}

.card h3 {
  margin-bottom: 0.4rem;
}

.card p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

.card-link {
  display: inline-block;
  margin-top: 0.75rem;
  font-weight: 700;
}

/* Tool card (used on hub pages) */
.tool-card {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.tool-card .tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 0.5rem;
}

.tag {
  display: inline-block;
  font-size: 0.74rem;
  font-weight: 700;
  color: var(--brand-700);
  background: var(--color-primary-soft);
  border: 1px solid var(--color-primary-border);
  border-radius: var(--radius-pill);
  padding: 0.18rem 0.7rem;
}

.tag-neutral {
  color: var(--color-text-muted);
  background: var(--color-bg-inset);
  border-color: var(--color-border);
}

/* Steps (how it works) — connected process */
.steps {
  list-style: none;
  counter-reset: step;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1.1rem;
  position: relative;
}

.step {
  counter-increment: step;
  position: relative;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.6rem 1.5rem 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base), box-shadow var(--transition-base),
    border-color var(--transition-base);
}

.step:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--brand-300);
}

.step::before {
  content: "0" counter(step);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  height: 44px;
  padding-inline: 6px;
  border-radius: 14px;
  background: var(--grad-primary);
  color: #ffffff;
  font-weight: 800;
  font-size: 0.95rem;
  letter-spacing: 0.03em;
  margin-bottom: 0.9rem;
  box-shadow: var(--glow-brand-soft);
}

.step::after {
  /* connector line to the next card (desktop) */
  content: "";
  position: absolute;
  top: 38px;
  left: calc(100% - 6px);
  width: 26px;
  height: 2px;
  background: repeating-linear-gradient(90deg, var(--brand-400) 0 6px, transparent 6px 11px);
  opacity: 0;
}

.step h3 {
  margin-bottom: 0.35rem;
}

.step p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

/* Use case / audience blocks */
.usecase {
  position: relative;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.25rem 1.35rem;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base), box-shadow var(--transition-base),
    border-color var(--transition-base);
  overflow: hidden;
}

.usecase::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: linear-gradient(180deg, var(--brand-400), var(--teal-500));
  opacity: 0.85;
}

.usecase:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--brand-300);
}

.usecase h3 {
  font-size: 1.02rem;
  margin-bottom: 0.3rem;
}

.usecase p {
  color: var(--color-text-muted);
  font-size: 0.92rem;
  margin: 0;
}

/* CTA banner */
.cta-banner {
  position: relative;
  background:
    radial-gradient(40rem 18rem at 88% -18%, rgba(16, 185, 129, 0.28) 0%, transparent 60%),
    radial-gradient(30rem 16rem at 6% 120%, rgba(20, 184, 166, 0.2) 0%, transparent 55%),
    linear-gradient(140deg, var(--ink-850) 0%, var(--ink-900) 60%, #0c1a13 100%);
  color: var(--dark-text-muted);
  border: 1px solid var(--dark-border);
  border-radius: var(--radius-xl);
  padding: 2.6rem 1.6rem;
  text-align: center;
  overflow: hidden;
  box-shadow: var(--shadow-xl);
}

.cta-banner::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.028) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.028) 1px, transparent 1px);
  background-size: 36px 36px;
  mask-image: radial-gradient(60% 90% at 50% 50%, #000 20%, transparent 100%);
  -webkit-mask-image: radial-gradient(60% 90% at 50% 50%, #000 20%, transparent 100%);
  pointer-events: none;
}

.cta-banner > * {
  position: relative;
}

.cta-banner h2 {
  color: #ffffff;
  margin-bottom: 0.55rem;
  font-size: clamp(1.5rem, 3vw, 2rem);
}

.cta-banner p {
  color: var(--dark-text-muted);
  max-width: 36rem;
  margin: 0 auto 1.5rem;
}

.cta-banner .btn-primary {
  background: linear-gradient(135deg, #ffffff, #e6fbf1);
  color: var(--brand-800);
  box-shadow: 0 14px 34px -12px rgba(0, 0, 0, 0.55);
}

.cta-banner .btn-primary:hover:not(:disabled) {
  background: #ffffff;
  color: var(--brand-800);
  transform: translateY(-2px);
}

/* --------------------------------------------------------------------------
   9. Tables
   -------------------------------------------------------------------------- */
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  box-shadow: var(--shadow-sm);
}

.table-wrap table {
  min-width: 560px;
}

.table-wrap th,
.table-wrap td {
  text-align: left;
  padding: 0.8rem 1.05rem;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.93rem;
  vertical-align: top;
}

.table-wrap thead th {
  background: linear-gradient(180deg, var(--color-bg-subtle), #f6faf7);
  font-weight: 800;
  white-space: nowrap;
  color: var(--color-text);
}

.table-wrap tbody tr:last-child td {
  border-bottom: none;
}

.table-wrap tbody tr {
  transition: background-color var(--transition-fast);
}

.table-wrap tbody tr:hover {
  background: var(--color-primary-soft);
}

/* --------------------------------------------------------------------------
   10. FAQ accordion (native <details>, accessible without JS)
   -------------------------------------------------------------------------- */
.faq-list {
  display: grid;
  gap: 0.7rem;
}

.faq-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color var(--transition-fast), box-shadow var(--transition-base);
}

.faq-item:hover {
  border-color: var(--brand-300);
}

.faq-item[open] {
  border-color: var(--brand-300);
  box-shadow: var(--shadow-md);
}

.faq-item summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.05rem 1.25rem;
  font-weight: 700;
  transition: background-color var(--transition-fast);
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary:hover {
  background: var(--color-primary-soft);
}

.faq-item summary .faq-icon {
  flex: 0 0 auto;
  margin-top: 0.2rem;
  color: var(--brand-600);
  background: var(--color-primary-soft);
  border-radius: 50%;
  padding: 3px;
  width: 24px;
  height: 24px;
  transition: transform var(--transition-base), background-color var(--transition-fast),
    color var(--transition-fast);
}

.faq-item[open] summary .faq-icon {
  transform: rotate(45deg);
  background: var(--brand-600);
  color: #ffffff;
}

.faq-question {
  font-size: 1rem;
  font-weight: 700;
  margin: 0;
}

.faq-answer {
  padding: 0.1rem 1.25rem 1.2rem;
  color: var(--color-text-muted);
  font-size: 0.95rem;
  animation: faq-reveal 0.28s var(--ease-out);
}

@keyframes faq-reveal {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: translateY(0); }
}

.faq-answer p + p {
  margin-top: 0.6rem;
}

/* --------------------------------------------------------------------------
   11. Breadcrumbs
   -------------------------------------------------------------------------- */
.breadcrumbs {
  padding-block: 0.95rem;
}

.breadcrumbs ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem;
  margin: 0;
  padding: 0;
  font-size: 0.85rem;
}

.breadcrumbs li {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin: 0;
  color: var(--color-text-faint);
}

.breadcrumbs li + li::before {
  content: "/";
  color: var(--color-border-strong);
}

.breadcrumbs a {
  color: var(--color-text-muted);
  text-decoration: none;
  font-weight: 600;
}

.breadcrumbs a:hover {
  color: var(--brand-600);
  text-decoration: underline;
}

.breadcrumbs [aria-current="page"] {
  color: var(--color-text-faint);
  font-weight: 600;
}

/* --------------------------------------------------------------------------
   12. Page hero (interior pages)
   -------------------------------------------------------------------------- */
.page-hero {
  position: relative;
  background:
    radial-gradient(44rem 20rem at 88% -30%, rgba(16, 185, 129, 0.12) 0%, transparent 62%),
    radial-gradient(30rem 16rem at -6% 130%, rgba(20, 184, 166, 0.08) 0%, transparent 55%),
    linear-gradient(180deg, #eefaf3 0%, var(--color-bg) 100%);
  border-bottom: 1px solid var(--color-border);
  padding-block: 2.6rem 2.3rem;
  overflow: hidden;
}

.page-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(rgba(5, 150, 105, 0.07) 1px, transparent 1px);
  background-size: 22px 22px;
  mask-image: linear-gradient(180deg, #000 0%, transparent 90%);
  -webkit-mask-image: linear-gradient(180deg, #000 0%, transparent 90%);
  pointer-events: none;
}

.page-hero > .container {
  position: relative;
}

.page-hero h1 {
  margin-bottom: 0.6rem;
  font-size: clamp(1.85rem, 4.2vw, 2.6rem);
}

.page-hero .lede {
  color: var(--color-text-muted);
  max-width: 46rem;
  font-size: 1.05rem;
}

/* Dark variant used on the tool page */
.page-hero-dark {
  background:
    radial-gradient(50rem 26rem at 85% -20%, rgba(16, 185, 129, 0.2) 0%, transparent 60%),
    var(--ink-950);
  border-bottom: 1px solid var(--dark-border);
  color: var(--dark-text-muted);
  padding-block: 2.6rem 4.6rem;
}

.page-hero-dark::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.028) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.028) 1px, transparent 1px);
  background-size: 42px 42px;
  mask-image: radial-gradient(70% 80% at 50% 20%, #000 25%, transparent 100%);
  -webkit-mask-image: radial-gradient(70% 80% at 50% 20%, #000 25%, transparent 100%);
  pointer-events: none;
}

.page-hero-dark h1 {
  color: #ffffff;
}

.page-hero-dark .lede {
  color: var(--dark-text-muted);
}

.page-hero-dark .breadcrumbs a {
  color: var(--dark-text-muted);
}

.page-hero-dark .breadcrumbs a:hover {
  color: var(--brand-300);
}

.page-hero-dark .breadcrumbs li {
  color: var(--dark-text-faint);
}

.page-hero-dark .breadcrumbs [aria-current="page"] {
  color: var(--dark-text-faint);
}

/* --------------------------------------------------------------------------
   13. Tool UI — premium editor workspace
   -------------------------------------------------------------------------- */
.tool-window {
  position: relative;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  overflow: hidden;
  min-width: 0;
}

/* Slim app-style titlebar */
.tool-titlebar {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  padding: 0.65rem 1.1rem;
  background: linear-gradient(180deg, #10231b, var(--ink-900));
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.tool-titlebar .tb-dots {
  display: inline-flex;
  gap: 6px;
  flex: 0 0 auto;
}

.tool-titlebar .tb-dots span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.16);
}

.tool-titlebar .tb-dots span:first-child {
  background: rgba(52, 211, 153, 0.75);
}

.tool-titlebar .tb-title {
  color: var(--dark-text);
  font-weight: 700;
  font-size: 0.86rem;
  letter-spacing: 0.01em;
}

.tool-titlebar .tb-chip {
  margin-left: auto;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--brand-300);
  background: rgba(16, 185, 129, 0.12);
  border: 1px solid rgba(110, 231, 183, 0.3);
  padding: 0.22rem 0.6rem;
  border-radius: var(--radius-pill);
  white-space: nowrap;
}

.tool-window > [hidden],
.tool-window [hidden] {
  display: none !important;
}

.tool-body {
  padding: 1.25rem;
}

/* Workspace split (editor state): preview left, controls right */
.workspace {
  display: grid;
  gap: 1.25rem;
}

.panel-title {
  font-size: 1rem;
  font-weight: 800;
  margin-bottom: 0.75rem;
  letter-spacing: -0.01em;
}

/* Dropzone (empty state) */
.dropzone {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: 0.55rem;
  padding: 3rem 1.4rem;
  border: 1.6px dashed var(--color-border-strong);
  border-radius: var(--radius-lg);
  background:
    radial-gradient(rgba(5, 150, 105, 0.1) 1px, transparent 1.4px) 0 0 / 20px 20px,
    linear-gradient(180deg, #fbfdfc 0%, #f2f8f4 100%);
  cursor: pointer;
  transition: border-color var(--transition-fast), background-color var(--transition-fast),
    box-shadow var(--transition-base), transform var(--transition-base);
}

.dropzone:hover,
.dropzone:focus-visible {
  border-color: var(--brand-500);
  box-shadow: 0 0 0 4px rgba(16, 185, 129, 0.12);
}

.dropzone.dragover {
  border-color: var(--brand-500);
  background:
    radial-gradient(rgba(5, 150, 105, 0.16) 1px, transparent 1.4px) 0 0 / 20px 20px,
    linear-gradient(180deg, #ecfdf5 0%, #dcf7ea 100%);
  box-shadow: 0 0 0 5px rgba(16, 185, 129, 0.18), var(--glow-brand-soft);
  transform: scale(1.005);
}

.dropzone.dragover .dropzone-icon {
  animation: dz-bounce 0.9s var(--ease-out) infinite;
}

@keyframes dz-bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-7px); }
}

.dropzone-icon {
  color: var(--brand-600);
  margin-bottom: 0.3rem;
  transition: transform var(--transition-base);
}

.dz-icon-wrap {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 74px;
  height: 74px;
  border-radius: 22px;
  background: linear-gradient(135deg, var(--color-primary-soft), #d7f4e6);
  border: 1px solid var(--color-primary-border);
  box-shadow: inset 0 0 0 4px rgba(255, 255, 255, 0.6);
  margin-bottom: 0.6rem;
}

.dz-title {
  font-weight: 800;
  font-size: 1.12rem;
  letter-spacing: -0.01em;
}

.dz-hint {
  color: var(--color-text-faint);
  font-size: 0.9rem;
}

.dz-formats {
  color: var(--color-text-faint);
  font-size: 0.8rem;
  margin-top: 0.5rem;
}

.dz-privacy {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  margin-top: 0.65rem;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--brand-700);
  background: var(--color-primary-soft);
  border: 1px solid var(--color-primary-border);
  border-radius: var(--radius-pill);
  padding: 0.28rem 0.8rem;
}

/* Preview + file meta */
.preview-grid {
  display: grid;
  gap: 1.25rem;
}

.preview-box {
  position: relative;
  background:
    repeating-conic-gradient(#e9efeb 0% 25%, #ffffff 0% 50%) 50% / 22px 22px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 0.8rem;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 220px;
  box-shadow: inset 0 2px 10px rgba(13, 26, 19, 0.05);
}

.preview-box img {
  max-width: 100%;
  max-height: 340px;
  width: auto;
  height: auto;
  border-radius: var(--radius-md);
  box-shadow: 0 14px 34px -14px rgba(13, 26, 19, 0.4);
  background: #ffffff;
}

.meta-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--color-surface);
}

.meta-list li {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.58rem 0.95rem;
  font-size: 0.9rem;
  border-bottom: 1px solid var(--color-border);
  margin: 0;
}

.meta-list li:last-child {
  border-bottom: none;
}

.meta-list li:nth-child(odd) {
  background: var(--color-bg-subtle);
}

.meta-list .meta-label {
  color: var(--color-text-muted);
  flex: 0 0 auto;
}

.meta-list .meta-value {
  font-weight: 700;
  text-align: right;
  overflow-wrap: anywhere;
  font-variant-numeric: tabular-nums;
}

/* Controls */
.controls-grid {
  display: grid;
  gap: 1.4rem;
  margin-top: 1.5rem;
  border-top: 1px solid var(--color-border);
  padding-top: 1.5rem;
}

.control-group {
  border: none;
  margin: 0;
  padding: 0;
  min-width: 0;
}

.control-group legend {
  font-weight: 800;
  font-size: 0.92rem;
  padding: 0;
  margin-bottom: 0.6rem;
  letter-spacing: -0.01em;
}

.control-hint {
  font-size: 0.82rem;
  color: var(--color-text-faint);
  margin-top: 0.45rem;
}

.field-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.9rem;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  min-width: 0;
}

.field label {
  font-weight: 700;
  font-size: 0.88rem;
}

/* Dimension inputs with unit suffix */
.input-unit {
  position: relative;
  display: flex;
  align-items: stretch;
}

.input-unit input[type="number"] {
  padding-right: 2.6rem;
  font-variant-numeric: tabular-nums;
  font-weight: 700;
}

.input-unit .unit {
  position: absolute;
  right: 0.85rem;
  top: 50%;
  transform: translateY(-50%);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--color-text-faint);
  pointer-events: none;
}

.field input[type="number"],
.field input[type="text"],
.field input[type="email"],
.field select,
.field textarea {
  width: 100%;
  min-height: 46px;
  padding: 0.55rem 0.8rem;
  font-family: inherit;
  font-size: 0.95rem;
  color: var(--color-text);
  background: var(--color-surface);
  border: 1.5px solid var(--color-border-strong);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.field textarea {
  resize: vertical;
  min-height: 120px;
}

.field input:hover,
.field select:hover,
.field textarea:hover {
  border-color: var(--brand-400);
}

.field input:focus,
.field select:focus,
.field textarea:focus {
  border-color: var(--brand-500);
  box-shadow: 0 0 0 4px rgba(16, 185, 129, 0.14);
  outline: none;
}

.field input[aria-invalid="true"] {
  border-color: var(--color-danger);
}

.field .field-error {
  color: var(--color-danger);
  font-size: 0.82rem;
  font-weight: 600;
}

/* Aspect lock row */
.lock-row {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  margin-top: 0.95rem;
  padding: 0.6rem 0.85rem;
  background: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.lock-row.is-locked {
  background: var(--color-primary-soft);
  border-color: var(--color-primary-border);
}

.lock-icon {
  display: inline-flex;
  color: var(--color-text-faint);
  transition: color var(--transition-fast), transform var(--transition-base);
}

.lock-row.is-locked .lock-icon {
  color: var(--brand-600);
  transform: scale(1.08);
}

/* Segmented control (resize mode tabs) */
.segmented {
  display: inline-flex;
  padding: 4px;
  gap: 4px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg-subtle);
}

.segmented label {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 0 1.15rem;
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--color-text-muted);
  cursor: pointer;
  border-radius: 9px;
  transition: background-color var(--transition-fast), color var(--transition-fast),
    box-shadow var(--transition-fast);
}

.segmented input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.segmented label:has(input:checked) {
  background: var(--color-surface);
  color: var(--brand-700);
  box-shadow: 0 1px 3px rgba(13, 26, 19, 0.14), 0 0 0 1px var(--color-primary-border);
}

.segmented label:has(input:focus-visible) {
  outline: 3px solid var(--brand-500);
  outline-offset: 1px;
}

/* Toggle switch */
.switch-row {
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.switch {
  position: relative;
  display: inline-flex;
  flex: 0 0 auto;
}

.switch input {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
  margin: 0;
}

.switch .track {
  width: 46px;
  height: 26px;
  background: var(--color-border-strong);
  border-radius: var(--radius-pill);
  transition: background-color var(--transition-fast);
  display: block;
  position: relative;
}

.switch .track::after {
  content: "";
  position: absolute;
  top: 3px;
  left: 3px;
  width: 20px;
  height: 20px;
  background: #ffffff;
  border-radius: 50%;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base);
}

.switch input:checked + .track {
  background: var(--brand-500);
}

.switch input:checked + .track::after {
  transform: translateX(20px);
}

.switch input:focus-visible + .track {
  outline: 3px solid var(--brand-500);
  outline-offset: 2px;
}

.switch-label {
  font-weight: 700;
  font-size: 0.9rem;
  cursor: pointer;
}

/* Preset chips */
.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.chip {
  display: inline-flex;
  align-items: center;
  min-height: 38px;
  padding: 0.32rem 0.95rem;
  font-family: inherit;
  font-size: 0.84rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--color-text-muted);
  background: var(--color-surface);
  border: 1.5px solid var(--color-border-strong);
  border-radius: var(--radius-pill);
  cursor: pointer;
  transition: background-color var(--transition-fast), color var(--transition-fast),
    border-color var(--transition-fast), transform var(--transition-fast),
    box-shadow var(--transition-fast);
}

.chip:hover {
  border-color: var(--brand-500);
  color: var(--brand-700);
  background: var(--color-primary-soft);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px -6px rgba(5, 150, 105, 0.4);
}

.chip:active {
  transform: translateY(0);
}

.chip[aria-pressed="true"] {
  background: var(--grad-primary);
  border-color: transparent;
  color: #ffffff;
  box-shadow: var(--glow-brand-soft);
}

/* Format selector cards */
.format-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(96px, 1fr));
  gap: 0.55rem;
}

.format-card {
  position: relative;
  display: block;
  cursor: pointer;
}

.format-card input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.format-card .fc-body {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.1rem;
  padding: 0.65rem 0.5rem;
  border: 1.5px solid var(--color-border-strong);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  text-align: center;
  transition: border-color var(--transition-fast), background-color var(--transition-fast),
    box-shadow var(--transition-fast), transform var(--transition-fast);
}

.format-card .fc-body strong {
  font-size: 0.92rem;
  font-weight: 800;
  letter-spacing: 0.02em;
}

.format-card .fc-body small {
  font-size: 0.7rem;
  color: var(--color-text-faint);
  font-weight: 600;
}

.format-card:hover .fc-body {
  border-color: var(--brand-400);
  transform: translateY(-1px);
}

.format-card input:checked + .fc-body {
  border-color: var(--brand-500);
  background: var(--color-primary-soft);
  box-shadow: 0 0 0 1px var(--brand-500), 0 6px 16px -8px rgba(5, 150, 105, 0.45);
}

.format-card input:checked + .fc-body strong {
  color: var(--brand-700);
}

.format-card input:focus-visible + .fc-body {
  outline: 3px solid var(--brand-500);
  outline-offset: 2px;
}

.format-card.is-disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.format-card.is-disabled .fc-body {
  background: var(--color-bg-inset);
  border-style: dashed;
}

/* Quality slider */
.quality-row {
  display: flex;
  align-items: center;
  gap: 0.9rem;
}

.quality-row input[type="range"] {
  flex: 1 1 auto;
  -webkit-appearance: none;
  appearance: none;
  height: 8px;
  min-height: 44px;
  background: transparent;
  cursor: pointer;
}

/* Track drawn via background gradient on the input itself (webkit) */
.quality-row input[type="range"]::-webkit-slider-runnable-track {
  height: 8px;
  border-radius: var(--radius-pill);
  background:
    linear-gradient(90deg, var(--brand-500), var(--teal-500)) 0 0 / var(--fill, 85%) 100% no-repeat,
    var(--color-bg-inset);
}

.quality-row input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 22px;
  height: 22px;
  margin-top: -7px;
  border-radius: 50%;
  background: #ffffff;
  border: 2.5px solid var(--brand-600);
  box-shadow: 0 2px 10px rgba(5, 150, 105, 0.45);
  transition: transform var(--transition-fast);
}

.quality-row input[type="range"]:hover::-webkit-slider-thumb,
.quality-row input[type="range"]:active::-webkit-slider-thumb {
  transform: scale(1.12);
}

.quality-row input[type="range"]::-moz-range-track {
  height: 8px;
  border-radius: var(--radius-pill);
  background: var(--color-bg-inset);
}

.quality-row input[type="range"]::-moz-range-progress {
  height: 8px;
  border-radius: var(--radius-pill);
  background: linear-gradient(90deg, var(--brand-500), var(--teal-500));
}

.quality-row input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: #ffffff;
  border: 2.5px solid var(--brand-600);
  box-shadow: 0 2px 10px rgba(5, 150, 105, 0.45);
}

.quality-row input[type="range"]:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.quality-value {
  font-variant-numeric: tabular-nums;
  font-weight: 800;
  font-size: 1rem;
  min-width: 3.2rem;
  text-align: right;
  color: var(--brand-700);
}

#quality-field.is-disabled .quality-row {
  opacity: 0.55;
}

/* Primary tool action */
.tool-action {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.9rem;
}

#resize-btn {
  min-width: 220px;
  font-size: 1.02rem;
}

#resize-btn.is-success {
  background: linear-gradient(135deg, #0ca678, #047857);
}

/* State banners */
.state-banner {
  display: flex;
  align-items: flex-start;
  gap: 0.7rem;
  padding: 0.9rem 1.05rem;
  border-radius: var(--radius-md);
  font-size: 0.92rem;
  font-weight: 500;
  border: 1px solid;
  margin-bottom: 1rem;
  animation: banner-in 0.3s var(--ease-out);
}

@keyframes banner-in {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: translateY(0); }
}

.state-banner strong {
  display: block;
  font-weight: 800;
}

.state-error {
  background: var(--color-danger-bg);
  border-color: var(--color-danger-border);
  color: var(--color-danger);
}

.state-success {
  background: var(--color-success-bg);
  border-color: var(--color-success-border);
  color: var(--color-success);
}

.state-info {
  background: var(--color-warning-bg);
  border-color: var(--color-warning-border);
  color: var(--color-warning);
}

.state-banner .banner-icon {
  flex: 0 0 auto;
  margin-top: 0.1rem;
}

/* Processing / spinner */
.spinner {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  border: 3px solid var(--color-primary-border);
  border-top-color: var(--brand-600);
  animation: spin 0.8s linear infinite;
  display: inline-block;
  vertical-align: -4px;
}

.spinner-lg {
  width: 42px;
  height: 42px;
  border-width: 4px;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.processing-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  padding: 3rem 1rem;
  text-align: center;
  color: var(--color-text-muted);
}

/* Result panel */
.result-grid {
  display: grid;
  gap: 1.25rem;
  margin-top: 0.25rem;
}

.result-check {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: var(--grad-bright);
  color: #053b2a;
  flex: 0 0 auto;
  animation: pop-in 0.45s var(--ease-out);
  box-shadow: 0 8px 20px -8px rgba(20, 184, 166, 0.7);
}

@keyframes pop-in {
  0% { transform: scale(0.4); opacity: 0; }
  70% { transform: scale(1.12); }
  100% { transform: scale(1); opacity: 1; }
}

.result-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(132px, 1fr));
  gap: 0.7rem;
}

.stat-card {
  background: linear-gradient(180deg, var(--color-bg-subtle), #f6faf7);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 0.8rem 0.9rem;
  text-align: center;
}

.stat-card .stat-label {
  display: block;
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--color-text-faint);
  margin-bottom: 0.2rem;
}

.stat-card .stat-value {
  font-weight: 800;
  font-size: 1.02rem;
  overflow-wrap: anywhere;
  font-variant-numeric: tabular-nums;
}

.result-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-top: 1.25rem;
}

.result-actions .btn-primary:hover .download-icon {
  transform: translateY(2px);
}

.download-icon {
  transition: transform var(--transition-base);
}

/* Tool page tip box */
.tip-box {
  background: var(--color-primary-soft);
  border: 1px solid var(--color-primary-border);
  border-radius: var(--radius-md);
  padding: 0.9rem 1.1rem;
  font-size: 0.9rem;
  color: var(--brand-800);
  margin-top: 1rem;
}

/* Decorative floating badge around the tool window */
.tool-float-badge {
  position: absolute;
  z-index: 2;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.4rem 0.8rem;
  border-radius: var(--radius-pill);
  background: rgba(19, 38, 32, 0.92);
  border: 1px solid var(--dark-border-strong);
  color: var(--brand-300);
  font-size: 0.76rem;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  box-shadow: 0 14px 30px -10px rgba(0, 0, 0, 0.55);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  pointer-events: none;
  animation: hv-float-badge 5.5s ease-in-out infinite;
}

/* --------------------------------------------------------------------------
   14. Prose / article content
   -------------------------------------------------------------------------- */
.prose {
  max-width: 46rem;
  min-width: 0; /* grid item: never let tables/formula inflate the column */
}

.prose h2 {
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
  padding-top: 0.4rem;
  font-size: 1.5rem;
}

.prose h3 {
  margin-top: 1.7rem;
  margin-bottom: 0.5rem;
}

.prose p {
  margin-bottom: 1rem;
  color: var(--color-text-muted);
}

.prose ul,
.prose ol {
  margin-bottom: 1rem;
  color: var(--color-text-muted);
}

.prose li::marker {
  color: var(--brand-600);
  font-weight: 700;
}

.prose strong {
  color: var(--color-text);
}

.prose blockquote {
  border-left: 4px solid var(--brand-500);
  background: linear-gradient(90deg, var(--color-primary-soft), transparent 130%);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: 0.95rem 1.25rem;
  margin: 1.3rem 0;
  color: var(--color-text-muted);
  font-style: italic;
}

.prose .table-wrap {
  margin: 1.3rem 0;
}

.prose .formula {
  background: linear-gradient(135deg, #0e1a14, var(--ink-900));
  border: 1px solid var(--dark-border-strong);
  border-radius: var(--radius-md);
  padding: 1.05rem 1.3rem;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  margin: 1.2rem 0;
  overflow-x: auto;
  color: var(--brand-300);
  box-shadow: inset 0 0 24px rgba(16, 185, 129, 0.07);
}

/* Visual formula/education card (light) */
.edu-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.4rem;
  margin: 1.3rem 0;
  box-shadow: var(--shadow-sm);
}

.edu-card .edu-label {
  font-size: 0.74rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--brand-600);
  margin-bottom: 0.6rem;
}

.edu-card .edu-flow {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.6rem 0.9rem;
  font-variant-numeric: tabular-nums;
  font-weight: 800;
}

.edu-card .edu-flow .edu-dim {
  background: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 0.35rem 0.7rem;
}

.edu-card .edu-flow .edu-dim-out {
  background: var(--color-primary-soft);
  border: 1px solid var(--color-primary-border);
  color: var(--brand-800);
  border-radius: var(--radius-sm);
  padding: 0.35rem 0.7rem;
}

.edu-card .edu-arrow {
  color: var(--brand-600);
  font-weight: 800;
}

/* Callout / tip variants in prose */
.callout {
  display: flex;
  gap: 0.75rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--brand-500);
  border-radius: var(--radius-md);
  padding: 1rem 1.15rem;
  margin: 1.3rem 0;
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

.callout .callout-icon {
  color: var(--brand-600);
  flex: 0 0 auto;
  margin-top: 0.15rem;
}

.callout strong {
  color: var(--color-text);
}

/* Table of contents */
.toc {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.15rem 1.4rem;
  margin: 0 0 1.75rem;
  box-shadow: var(--shadow-sm);
}

.toc-title {
  font-size: 0.8rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--color-text-faint);
  margin-bottom: 0.55rem;
}

.toc ol {
  margin: 0;
  padding-left: 1.15rem;
  font-size: 0.92rem;
  columns: 1;
}

.toc a {
  text-decoration: none;
  font-weight: 600;
}

.toc a:hover {
  text-decoration: underline;
  color: var(--brand-600);
}

/* Article layout with sidebar */
.article-layout {
  display: grid;
  gap: 2rem;
  padding-block: 2.5rem;
}

.article-sidebar {
  display: none;
}

.sidebar-box {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.15rem 1.3rem;
  font-size: 0.92rem;
  box-shadow: var(--shadow-sm);
}

.sidebar-box + .sidebar-box {
  margin-top: 1rem;
}

.sidebar-box h2 {
  font-size: 0.95rem;
  margin-bottom: 0.6rem;
}

.sidebar-box ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.sidebar-box li {
  margin: 0;
}

.sidebar-box li a {
  display: block;
  padding: 0.4rem 0;
  text-decoration: none;
  font-weight: 600;
  border-bottom: 1px solid var(--color-border);
  transition: color var(--transition-fast), padding-left var(--transition-fast);
}

.sidebar-box li a:hover {
  color: var(--brand-600);
  padding-left: 4px;
}

.sidebar-box li:last-child a {
  border-bottom: none;
}

/* --------------------------------------------------------------------------
   15. Blog cards & article head
   -------------------------------------------------------------------------- */
.post-card {
  display: flex;
  flex-direction: column;
}

.post-card .post-topic {
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--brand-700);
  background: var(--color-primary-soft);
  border: 1px solid var(--color-primary-border);
  border-radius: var(--radius-pill);
  padding: 0.18rem 0.65rem;
  margin: 0 0 0.7rem;
  align-self: flex-start;
}

.post-card h3 {
  font-size: 1.12rem;
  margin-bottom: 0.4rem;
}

.post-card h3 a {
  color: var(--color-text);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.post-card h3 a:hover {
  color: var(--brand-600);
  text-decoration: underline;
}

.post-card p {
  color: var(--color-text-muted);
  font-size: 0.92rem;
  flex-grow: 1;
}

.post-card .post-link {
  margin-top: 0.95rem;
  font-weight: 700;
  font-size: 0.9rem;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

.post-card .post-link::after {
  content: "→";
  transition: transform var(--transition-fast);
}

.post-card:hover .post-link::after {
  transform: translateX(4px);
}

/* Featured article card */
.post-featured {
  position: relative;
  background:
    radial-gradient(36rem 16rem at 92% -30%, rgba(16, 185, 129, 0.13) 0%, transparent 60%),
    linear-gradient(180deg, #ffffff, #f4faf6);
  border: 1px solid var(--color-primary-border);
  box-shadow: var(--shadow-md);
}

.post-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem 0.9rem;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--color-text-faint);
  margin-top: 0.6rem;
}

.post-meta .meta-dot {
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--color-border-strong);
}

/* Article header on article pages */
.article-head {
  padding-block: 0.4rem 1.6rem;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 1.75rem;
}

.article-head h1 {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  margin-bottom: 0.7rem;
}

.article-head .lede {
  color: var(--color-text-muted);
  font-size: 1.06rem;
  max-width: 44rem;
}

/* --------------------------------------------------------------------------
   16. Forms (contact)
   -------------------------------------------------------------------------- */
.form-grid {
  display: grid;
  gap: 1rem;
}

.form-status {
  margin-top: 1rem;
}

/* --------------------------------------------------------------------------
   17. Footer
   -------------------------------------------------------------------------- */
.site-footer {
  position: relative;
  background:
    radial-gradient(44rem 20rem at 90% -20%, rgba(16, 185, 129, 0.09) 0%, transparent 60%),
    var(--ink-950);
  color: var(--dark-text-muted);
  padding: 3.25rem 0 1.75rem;
  font-size: 0.92rem;
  border-top: 1px solid var(--dark-border);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 50%;
  transform: translateX(-50%);
  width: min(560px, 70%);
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(52, 211, 153, 0.55), transparent);
}

.footer-grid {
  display: grid;
  gap: 2rem;
  grid-template-columns: 1fr;
}

.footer-brand .brand {
  color: #ffffff;
  margin-bottom: 0.7rem;
}

.footer-brand .brand-name span {
  color: var(--brand-400);
}

.footer-brand p {
  color: var(--dark-text-faint);
  max-width: 21rem;
}

.footer-col h2 {
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.11em;
  color: var(--dark-text);
  margin-bottom: 0.85rem;
}

.footer-col ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-col li {
  margin: 0 0 0.5rem;
}

.footer-col a {
  color: var(--dark-text-muted);
  text-decoration: none;
  transition: color var(--transition-fast), padding-left var(--transition-fast);
}

.footer-col a:hover {
  color: var(--brand-300);
  padding-left: 3px;
}

.footer-bottom {
  margin-top: 2.5rem;
  padding-top: 1.4rem;
  border-top: 1px solid var(--dark-border);
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  align-items: center;
  justify-content: space-between;
  color: var(--dark-text-faint);
  font-size: 0.85rem;
}

.footer-bottom ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.15rem;
  margin: 0;
  padding: 0;
}

.footer-bottom a {
  color: var(--dark-text-faint);
  text-decoration: none;
}

.footer-bottom a:hover {
  color: var(--brand-300);
  text-decoration: underline;
}

/* --------------------------------------------------------------------------
   18. Visualization section (dark, homepage)
   -------------------------------------------------------------------------- */
.viz-stage {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 1.6rem;
  padding: 2.4rem 1rem 2rem;
  perspective: 1100px;
}

.viz-card {
  position: relative;
  border-radius: var(--radius-lg);
  background: linear-gradient(180deg, #14261e, #0d1813);
  border: 1px solid var(--dark-border-strong);
  padding: 10px;
  box-shadow:
    -22px 30px 56px -20px rgba(0, 0, 0, 0.6),
    0 0 0 1px rgba(52, 211, 153, 0.05) inset;
  transform: rotateX(7deg) rotateY(-10deg);
  transform-style: preserve-3d;
}

.viz-card-original {
  width: min(300px, 62vw);
  aspect-ratio: 4 / 3;
}

.viz-card-result {
  width: min(190px, 44vw);
  aspect-ratio: 4 / 3;
}

/* ghost stacked cards behind the original */
.viz-card::before,
.viz-card::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  border: 1px solid var(--dark-border);
  background: rgba(14, 26, 20, 0.55);
  z-index: -1;
}

.viz-card::before {
  transform: translate3d(10px, 10px, -34px);
}

.viz-card::after {
  transform: translate3d(19px, 19px, -62px);
  background: rgba(12, 22, 17, 0.4);
}

.viz-badge {
  position: absolute;
  top: -15px;
  left: 50%;
  translate: -50% 0;
  padding: 0.32rem 0.75rem;
  border-radius: var(--radius-pill);
  font-size: 0.76rem;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
  transform: translateZ(46px);
}

.viz-badge-src {
  color: #d9fbe9;
  background: rgba(6, 95, 70, 0.6);
  border: 1px solid rgba(110, 231, 183, 0.45);
  box-shadow: 0 10px 24px -8px rgba(0, 0, 0, 0.6);
}

.viz-badge-out {
  color: var(--brand-800);
  background: linear-gradient(135deg, var(--brand-300), var(--teal-400));
  box-shadow: 0 10px 24px -8px rgba(20, 184, 166, 0.55);
}

.viz-label {
  position: absolute;
  bottom: -32px;
  left: 50%;
  translate: -50% 0;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--dark-text-faint);
  white-space: nowrap;
}

.viz-arrow {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.55rem;
  transform: translateZ(30px);
}

.viz-arrow svg {
  width: 92px;
  height: 30px;
  overflow: visible;
}

.viz-arrow .hv-arrow-line {
  stroke-dasharray: 12 9;
  animation: hv-dash 1.3s linear infinite;
}

.viz-pill {
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: #062016;
  background: linear-gradient(135deg, var(--brand-300), var(--teal-400));
  padding: 0.4rem 0.95rem;
  border-radius: var(--radius-pill);
  box-shadow: 0 10px 26px -8px rgba(20, 184, 166, 0.6);
}

.viz-note {
  text-align: center;
  font-size: 0.86rem;
  color: var(--dark-text-faint);
  margin-top: 1.4rem;
}

/* --------------------------------------------------------------------------
   19. Reveal-on-scroll system
   Gated behind html.js (set by a tiny inline script in <head>).
   Without JavaScript, all content stays fully visible.
   -------------------------------------------------------------------------- */
html.js [data-reveal] {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.65s ease, transform 0.65s var(--ease-out);
  transition-delay: var(--reveal-delay, 0ms);
  will-change: opacity, transform;
}

html.js [data-reveal="scale"] {
  transform: translateY(14px) scale(0.97);
}

html.js [data-reveal="left"] {
  transform: translateX(-22px);
}

html.js [data-reveal].in-view {
  opacity: 1;
  transform: none;
}

/* --------------------------------------------------------------------------
   20. Breakpoints
   -------------------------------------------------------------------------- */
@media (min-width: 640px) {
  .container {
    padding-inline: 1.5rem;
  }

  h1 { font-size: 2.2rem; }

  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }

  .preview-grid {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    align-items: start;
  }

  .result-grid {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    align-items: start;
  }

  .steps {
    grid-template-columns: repeat(2, 1fr);
  }

  .controls-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .controls-grid .control-span {
    grid-column: 1 / -1;
  }

  .toc ol {
    columns: 2;
    column-gap: 2rem;
  }
}

@media (min-width: 768px) {
  .section {
    padding-block: 4rem;
  }

  .grid-3, .grid-4 {
    grid-template-columns: repeat(3, 1fr);
  }

  .hero {
    padding-block: 4.5rem 4.75rem;
  }

  .hero-inner {
    gap: 2.5rem;
  }

  .hero-visual {
    min-height: 460px;
  }

  .hv-scene {
    height: 460px;
  }

  .steps {
    grid-template-columns: repeat(4, 1fr);
  }

  .step::after {
    opacity: 1;
  }

  .step:last-child::after {
    display: none;
  }

  .footer-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .cta-banner {
    padding: 3.25rem 3rem;
  }

  .tool-body {
    padding: 1.75rem;
  }
}

@media (min-width: 1024px) {
  .container {
    padding-inline: 2rem;
  }

  /* Desktop navigation */
  .main-nav {
    display: block;
  }

  .nav-toggle {
    display: none;
  }

  .header-cta {
    display: inline-flex;
  }

  .grid-4 {
    grid-template-columns: repeat(4, 1fr);
  }

  .hero-inner {
    grid-template-columns: minmax(0, 1.02fr) minmax(0, 0.98fr);
    gap: 3rem;
  }

  .hero-visual {
    margin-inline: 0 auto;
  }

  /* 3D tilt only where a fine pointer + hover exists (JS also gates this) */
  .hero-visual:hover .hv-scene {
    transition: transform 0.18s ease-out;
  }

  /* Article layout: content + sticky sidebar */
  .article-layout {
    grid-template-columns: minmax(0, 1fr) 268px;
    align-items: start;
  }

  .article-sidebar {
    display: block;
    position: sticky;
    top: calc(var(--header-height) + 24px);
  }

  /* Tool workspace: preview + side controls */
  .workspace {
    grid-template-columns: minmax(0, 1.45fr) minmax(300px, 1fr);
    align-items: start;
  }

  .workspace .workspace-side {
    position: sticky;
    top: calc(var(--header-height) + 20px);
  }
}

@media (min-width: 1280px) {
  .footer-grid {
    grid-template-columns: 2.1fr 1fr 1fr 1.15fr 1fr;
  }
}

/* --------------------------------------------------------------------------
   21. Reduced motion
   -------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .spinner {
    animation-duration: 0.8s !important; /* keep the loading indicator functional */
  }

  /* Reveal animations must never hide content */
  html.js [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }

  /* Disable 3D scene movement + parallax */
  .hv-scene,
  .viz-card {
    transform: none !important;
    animation: none !important;
  }

  .hv-glow {
    animation: none !important;
  }
}

/* --------------------------------------------------------------------------
   22. Custom scrollbar for scrollable regions
   -------------------------------------------------------------------------- */
.table-wrap,
.prose .formula,
.nav-panel {
  scrollbar-width: thin;
  scrollbar-color: var(--color-border-strong) transparent;
}

.table-wrap::-webkit-scrollbar,
.prose .formula::-webkit-scrollbar {
  height: 8px;
}

.table-wrap::-webkit-scrollbar-thumb,
.prose .formula::-webkit-scrollbar-thumb {
  background: var(--color-border-strong);
  border-radius: var(--radius-pill);
}