/* ==========================================================================
   GHTE Studios — Design System
   Pure CSS, no frameworks. Apple-inspired: generous whitespace, restrained
   color, large confident type, soft depth, subtle motion.
   ========================================================================== */

/* ---------- Design tokens ---------- */
:root {
  --bg: #ffffff;
  --bg-elevated: #f5f5f7;
  --bg-elevated-2: #eef0f3;
  --text: #1d1d1f;
  --text-secondary: #6e6e73;
  --text-tertiary: #86868b;
  --border: rgba(0, 0, 0, 0.08);
  --border-strong: rgba(0, 0, 0, 0.14);
  --accent: #0071e3;
  --accent-hover: #0077ed;
  --accent-soft: rgba(0, 113, 227, 0.1);
  --accent-2: #7b5cff;
  --success: #1a7f37;
  --surface: #ffffff;
  --surface-alpha: rgba(255, 255, 255, 0.72);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04), 0 1px 1px rgba(0, 0, 0, 0.03);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08), 0 2px 6px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 24px 64px rgba(0, 0, 0, 0.12), 0 8px 24px rgba(0, 0, 0, 0.06);
  --radius-sm: 10px;
  --radius-md: 18px;
  --radius-lg: 28px;
  --radius-pill: 999px;
  --max-width: 1180px;
  --header-h: 64px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --transition-fast: 180ms var(--ease);
  --transition-base: 320ms var(--ease);
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
    "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color-scheme: light;
}

:root[data-theme="dark"] {
  --bg: #000000;
  --bg-elevated: #1c1c1e;
  --bg-elevated-2: #232326;
  --text: #f5f5f7;
  --text-secondary: #a1a1a6;
  --text-tertiary: #8e8e93;
  --border: rgba(255, 255, 255, 0.1);
  --border-strong: rgba(255, 255, 255, 0.18);
  --accent: #2997ff;
  --accent-hover: #47a6ff;
  --accent-soft: rgba(41, 151, 255, 0.16);
  --accent-2: #9b7bff;
  --surface: #1c1c1e;
  --surface-alpha: rgba(28, 28, 30, 0.72);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.45);
  --shadow-lg: 0 24px 64px rgba(0, 0, 0, 0.55);
  color-scheme: dark;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #000000;
    --bg-elevated: #1c1c1e;
    --bg-elevated-2: #232326;
    --text: #f5f5f7;
    --text-secondary: #a1a1a6;
    --text-tertiary: #8e8e93;
    --border: rgba(255, 255, 255, 0.1);
    --border-strong: rgba(255, 255, 255, 0.18);
    --accent: #2997ff;
    --accent-hover: #47a6ff;
    --accent-soft: rgba(41, 151, 255, 0.16);
    --accent-2: #9b7bff;
    --surface: #1c1c1e;
    --surface-alpha: rgba(28, 28, 30, 0.72);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.45);
    --shadow-lg: 0 24px 64px rgba(0, 0, 0, 0.55);
    color-scheme: dark;
  }
}

/* ---------- Reset ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--transition-base), color var(--transition-base);
  overflow-x: hidden;
}

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

a {
  color: inherit;
  text-decoration: none;
}

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

h1,
h2,
h3,
h4,
p {
  margin: 0;
}

button {
  font-family: inherit;
  cursor: pointer;
}

::selection {
  background: var(--accent-soft);
  color: var(--accent);
}

/* ---------- Layout helpers ---------- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 96px 0;
}

@media (max-width: 768px) {
  .section {
    padding: 64px 0;
  }
}

.section-header {
  max-width: 640px;
  margin: 0 auto 56px;
  text-align: center;
}

.section-header.align-left {
  margin: 0 0 48px;
  text-align: left;
}

.eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}

h1 {
  font-size: clamp(2.6rem, 6vw, 4.4rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.05;
}

h2 {
  font-size: clamp(2rem, 4vw, 2.75rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

h3 {
  font-size: 1.375rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.3;
}

p {
  color: var(--text-secondary);
  line-height: 1.6;
  font-size: 1.0625rem;
}

.lead {
  font-size: clamp(1.125rem, 2vw, 1.375rem);
  color: var(--text-secondary);
  line-height: 1.55;
}

.text-center {
  text-align: center;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: var(--radius-pill);
  font-size: 0.9375rem;
  font-weight: 600;
  border: 1px solid transparent;
  transition: transform var(--transition-fast), background-color var(--transition-fast),
    border-color var(--transition-fast), box-shadow var(--transition-fast), opacity var(--transition-fast);
  white-space: nowrap;
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.08);
}

.btn-primary:hover {
  background: var(--accent-hover);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background: var(--bg-elevated);
  color: var(--text);
  border-color: var(--border);
}

.btn-secondary:hover {
  background: var(--bg-elevated-2);
  border-color: var(--border-strong);
}

.btn-large {
  padding: 16px 32px;
  font-size: 1rem;
}

.btn-block {
  width: 100%;
}

/* ---------- Header / Nav ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-h);
  display: flex;
  align-items: center;
  background: var(--surface-alpha);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--border);
  transition: background-color var(--transition-base), border-color var(--transition-base);
}

.nav {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: -0.01em;
}

.brand img {
  width: 26px;
  height: 26px;
  border-radius: 7px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-links a {
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.nav-links a:hover {
  color: var(--text);
  background: var(--bg-elevated);
}

.nav-links a.active {
  color: var(--text);
  background: var(--bg-elevated);
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text);
  transition: background-color var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast);
}

.theme-toggle:hover {
  background: var(--bg-elevated-2);
  transform: rotate(12deg);
}

.theme-toggle svg {
  width: 18px;
  height: 18px;
}

.icon-sun {
  display: none;
}
:root[data-theme="dark"] .icon-moon {
  display: none;
}
:root[data-theme="dark"] .icon-sun {
  display: block;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .icon-moon {
    display: none;
  }
  :root:not([data-theme="light"]) .icon-sun {
    display: block;
  }
}

.nav-toggle {
  display: none;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  align-items: center;
  justify-content: center;
}

.nav-toggle svg {
  width: 18px;
  height: 18px;
}

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

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

@media (max-width: 860px) {
  .nav-links {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 8px 20px 20px;
    gap: 2px;
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity var(--transition-base), transform var(--transition-base), visibility var(--transition-base);
    box-shadow: var(--shadow-md);
  }

  .nav-links a {
    padding: 14px 12px;
    border-radius: var(--radius-sm);
  }

  body.nav-open .nav-links {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }

  .nav-toggle {
    display: flex;
  }
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  padding: calc(var(--header-h) + 96px) 0 96px;
  overflow: hidden;
  text-align: center;
}

.hero::before {
  content: "";
  position: absolute;
  inset: -20% -10% auto -10%;
  height: 720px;
  background: radial-gradient(60% 60% at 30% 20%, var(--accent-soft), transparent 70%),
    radial-gradient(50% 50% at 80% 10%, rgba(123, 92, 255, 0.12), transparent 70%);
  filter: blur(40px);
  z-index: -1;
  pointer-events: none;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: var(--radius-pill);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 28px;
}

.hero-badge .dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--success);
}

.hero h1 {
  max-width: 900px;
  margin: 0 auto;
}

.hero .gradient-text {
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero .lead {
  max-width: 620px;
  margin: 24px auto 40px;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 56px;
  margin-top: 88px;
  flex-wrap: wrap;
}

.hero-stat .num {
  font-size: 2.25rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.hero-stat .label {
  font-size: 0.875rem;
  color: var(--text-tertiary);
  margin-top: 4px;
}

/* ---------- Cards / Grids ---------- */
.grid {
  display: grid;
  gap: 20px;
}

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

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

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

@media (max-width: 900px) {
  .grid-3,
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 620px) {
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 32px;
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

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

.card-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  border-radius: 14px;
  background: var(--accent-soft);
  color: var(--accent);
  margin-bottom: 20px;
}

.card-icon svg {
  width: 26px;
  height: 26px;
}

.card h3 {
  margin-bottom: 10px;
}

.card p {
  font-size: 0.9375rem;
}

.card ul {
  margin-top: 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.card ul li {
  font-size: 0.875rem;
  color: var(--text-secondary);
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.card ul li::before {
  content: "";
  flex: none;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent);
  margin-top: 8px;
}

/* Panel — elevated flat surface (no border), for alternating sections */
.panel {
  background: var(--bg-elevated);
  border-radius: var(--radius-lg);
}

.section-alt {
  background: var(--bg-elevated);
}

/* ---------- CTA band ---------- */
.cta-band {
  border-radius: var(--radius-lg);
  padding: 72px 48px;
  text-align: center;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
  position: relative;
  overflow: hidden;
}

.cta-band h2 {
  color: #fff;
}

.cta-band p {
  color: rgba(255, 255, 255, 0.85);
  max-width: 520px;
  margin: 16px auto 32px;
}

.cta-band .btn-primary {
  background: #fff;
  color: var(--accent);
}

.cta-band .btn-primary:hover {
  background: rgba(255, 255, 255, 0.9);
}

.cta-band .btn-secondary {
  background: rgba(255, 255, 255, 0.14);
  border-color: rgba(255, 255, 255, 0.3);
  color: #fff;
}

.cta-band .btn-secondary:hover {
  background: rgba(255, 255, 255, 0.22);
}

@media (max-width: 620px) {
  .cta-band {
    padding: 48px 24px;
  }
}

/* ---------- Page header (non-home pages) ---------- */
.page-header {
  padding: calc(var(--header-h) + 72px) 0 64px;
  text-align: center;
}

.page-header .eyebrow {
  margin-bottom: 16px;
}

.page-header p {
  max-width: 620px;
  margin: 20px auto 0;
}

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 64px 0 32px;
  background: var(--bg);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 32px;
  margin-bottom: 48px;
}

@media (max-width: 760px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 480px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }
}

.footer-brand .brand {
  margin-bottom: 14px;
}

.footer-brand p {
  font-size: 0.875rem;
  max-width: 280px;
}

.footer-col h4 {
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-tertiary);
  margin-bottom: 16px;
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-col a {
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}

.footer-col a:hover {
  color: var(--text);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  padding-top: 28px;
  border-top: 1px solid var(--border);
  font-size: 0.8125rem;
  color: var(--text-tertiary);
}

.footer-bottom .legal-name {
  color: var(--text-tertiary);
}

/* ---------- Scroll reveal ---------- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 700ms var(--ease), transform 700ms var(--ease);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal-stagger > * {
  transition-delay: calc(var(--i, 0) * 80ms);
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
  * {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* ---------- Misc content sections ---------- */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

@media (max-width: 860px) {
  .two-col {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

.value-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--bg-elevated);
  color: var(--accent);
  margin-bottom: 16px;
}

.value-icon svg {
  width: 22px;
  height: 22px;
}

.badge-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.badge {
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-secondary);
}

/* ---------- Apps page ---------- */
.app-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 32px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.app-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.app-card-top {
  display: flex;
  align-items: center;
  gap: 16px;
}

.app-icon {
  width: 60px;
  height: 60px;
  border-radius: 16px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 700;
  font-size: 1.25rem;
  flex: none;
}

.app-status {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: var(--radius-pill);
  background: var(--accent-soft);
  color: var(--accent);
  width: fit-content;
}

.platform-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.platform-pill {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-tertiary);
  background: var(--bg-elevated);
  padding: 5px 10px;
  border-radius: var(--radius-pill);
}

.empty-state {
  text-align: center;
  padding: 64px 24px;
  border: 1px dashed var(--border-strong);
  border-radius: var(--radius-lg);
}

.empty-state .value-icon {
  margin: 0 auto 20px;
}

/* ---------- Contact page ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 48px;
  align-items: start;
}

@media (max-width: 860px) {
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

.contact-info-card {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 24px 0;
  border-bottom: 1px solid var(--border);
}

.contact-info-card:last-child {
  border-bottom: none;
}

.contact-info-card h4 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.contact-info-card a,
.contact-info-card span {
  font-size: 0.9375rem;
  color: var(--text-secondary);
}

.contact-info-card a:hover {
  color: var(--accent);
}

.form-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 40px;
}

@media (max-width: 480px) {
  .form-card {
    padding: 28px 20px;
  }
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

@media (max-width: 560px) {
  .form-row {
    grid-template-columns: 1fr;
  }
}

.field {
  margin-bottom: 20px;
}

.field label {
  display: block;
  font-size: 0.8125rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text);
}

.field input,
.field select,
.field textarea {
  width: 100%;
  padding: 13px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-strong);
  background: var(--bg-elevated);
  color: var(--text);
  font-family: inherit;
  font-size: 0.9375rem;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

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

.field input:focus,
.field select:focus,
.field textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-soft);
}

.form-note {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  margin-top: 14px;
  text-align: center;
}

.form-success {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 14px 16px;
  border-radius: var(--radius-sm);
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 20px;
}

.form-success.visible {
  display: flex;
}

/* ---------- Privacy / legal content ---------- */
.legal-content {
  max-width: 760px;
  margin: 0 auto;
}

.legal-content h2 {
  font-size: 1.375rem;
  margin-top: 48px;
  margin-bottom: 14px;
}

.legal-content h2:first-child {
  margin-top: 0;
}

.legal-content p,
.legal-content li {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  margin-bottom: 14px;
}

.legal-content ul {
  padding-left: 4px;
  margin-bottom: 14px;
}

.legal-content ul li {
  position: relative;
  padding-left: 20px;
  margin-bottom: 10px;
}

.legal-content ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent);
}

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

.legal-meta {
  display: inline-flex;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  margin-top: 12px;
}

.toc {
  background: var(--bg-elevated);
  border-radius: var(--radius-md);
  padding: 24px 28px;
  margin-bottom: 48px;
}

.toc h4 {
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-tertiary);
  margin-bottom: 14px;
}

.toc ol {
  margin: 0;
  padding-left: 20px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px 24px;
}

.toc a {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.toc a:hover {
  color: var(--accent);
}

@media (max-width: 560px) {
  .toc ol {
    grid-template-columns: 1fr;
  }
}

/* ---------- Back to top ---------- */
.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity var(--transition-fast), transform var(--transition-fast), visibility var(--transition-fast);
  z-index: 900;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top svg {
  width: 18px;
  height: 18px;
  color: var(--text);
}