/* =========================================================
   Free Chat — modern design system (2026)
   ========================================================= */

:root {
  color-scheme: dark;

  /* Surfaces */
  --bg: #07080d;
  --bg-soft: #0b0d15;
  --bg-elev: #0f1220;
  --surface: rgba(18, 21, 35, 0.72);
  --surface-strong: rgba(24, 27, 44, 0.92);
  --surface-glass: rgba(255, 255, 255, 0.04);

  /* Borders & lines */
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.16);
  --hairline: rgba(255, 255, 255, 0.06);

  /* Text */
  --text: #f5f6fb;
  --text-soft: #d1d5e1;
  --muted: #8b91a7;
  --dim: #5d627a;

  /* Brand accents */
  --accent: #7c5cff;
  --accent-2: #38bdf8;
  --accent-3: #34d399;
  --hot: #f472b6;

  /* AI brand colors */
  --c-chatgpt: #10a37f;
  --c-claude: #e89548;
  --c-gemini: #6e8aff;
  --c-grok: #ef4c4c;
  --c-deepseek: #5a78ff;
  --c-qwen: #b15cff;
  --c-llama: #f59e0b;
  --c-kimi: #18a0a3;
  --c-perplexity: #20b8a4;

  /* Geometry */
  --r-xs: 8px;
  --r-sm: 12px;
  --r-md: 18px;
  --r-lg: 26px;
  --r-xl: 36px;
  --r-pill: 999px;

  /* Shadows */
  --sh-sm: 0 4px 14px rgba(0, 0, 0, 0.35);
  --sh-md: 0 12px 40px rgba(0, 0, 0, 0.45);
  --sh-lg: 0 28px 90px rgba(0, 0, 0, 0.55);
  --glow-accent: 0 0 0 1px rgba(124, 92, 255, 0.4), 0 24px 80px rgba(124, 92, 255, 0.25);

  /* Type */
  --container: 1240px;
  --font:
    "Inter", "Plus Jakarta Sans", system-ui, -apple-system, BlinkMacSystemFont,
    "Segoe UI", Roboto, sans-serif;
  --font-display: "Inter", "Plus Jakarta Sans", system-ui, sans-serif;

  /* Motion */
  --t-fast: 140ms ease;
  --t-mid: 240ms cubic-bezier(0.2, 0.8, 0.2, 1);
  --t-slow: 480ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

/* Light theme override */
:root[data-theme="light"] {
  color-scheme: light;
  --bg: #f6f7fb;
  --bg-soft: #ffffff;
  --bg-elev: #ffffff;
  --surface: rgba(255, 255, 255, 0.86);
  --surface-strong: #ffffff;
  --surface-glass: rgba(15, 23, 42, 0.04);
  --border: rgba(15, 23, 42, 0.1);
  --border-strong: rgba(15, 23, 42, 0.18);
  --hairline: rgba(15, 23, 42, 0.06);
  --text: #0a0e1a;
  --text-soft: #1f2436;
  --muted: #5a6178;
  --dim: #8b91a7;
  --sh-sm: 0 4px 14px rgba(15, 23, 42, 0.06);
  --sh-md: 0 16px 40px rgba(15, 23, 42, 0.1);
  --sh-lg: 0 30px 80px rgba(15, 23, 42, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body.site-page {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  background: var(--bg);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  position: relative;
  overflow-x: hidden;
}

body.site-page::before,
body.site-page::after {
  content: "";
  position: fixed;
  pointer-events: none;
  z-index: 0;
  filter: blur(120px);
  opacity: 0.55;
  transition: opacity var(--t-slow);
}

body.site-page::before {
  top: -240px;
  left: -180px;
  width: 720px;
  height: 720px;
  background: radial-gradient(circle, rgba(124, 92, 255, 0.45), transparent 60%);
}

body.site-page::after {
  top: -120px;
  right: -200px;
  width: 720px;
  height: 720px;
  background: radial-gradient(circle, rgba(56, 189, 248, 0.38), transparent 60%);
}

:root[data-theme="light"] body.site-page::before,
:root[data-theme="light"] body.site-page::after {
  opacity: 0.32;
}

body.chat-page {
  height: 100vh;
  overflow: hidden;
}

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

img {
  max-width: 100%;
  height: auto;
}

/* ============== layout ============== */

main {
  position: relative;
  z-index: 1;
}

.site-container {
  width: min(100% - 32px, var(--container));
  margin-inline: auto;
}

.site-section {
  padding: clamp(64px, 8vw, 120px) 0;
  position: relative;
}

.site-section.tight {
  padding: clamp(28px, 4vw, 48px) 0;
}

.section-head {
  display: grid;
  gap: 14px;
  max-width: 760px;
  margin: 0 auto 48px;
  text-align: center;
}

/* ============== type ============== */

.title-xl,
.title-lg,
.title-md,
.title-sm {
  margin: 0;
  color: var(--text);
  font-family: var(--font-display);
  font-weight: 800;
  letter-spacing: -0.045em;
}

.title-xl {
  font-size: clamp(2.6rem, 7vw, 5.6rem);
  line-height: 0.98;
  letter-spacing: -0.06em;
  font-weight: 900;
}

.title-lg {
  font-size: clamp(2rem, 4.4vw, 3.6rem);
  line-height: 1.04;
  letter-spacing: -0.04em;
}

.title-md {
  font-size: clamp(1.3rem, 2vw, 1.75rem);
  line-height: 1.2;
  letter-spacing: -0.025em;
}

.title-sm {
  font-size: clamp(1.05rem, 1.5vw, 1.25rem);
  line-height: 1.3;
  letter-spacing: -0.015em;
}

.lead {
  margin: 0;
  color: var(--muted);
  font-size: clamp(1rem, 1.45vw, 1.18rem);
  line-height: 1.65;
}

.lead-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  vertical-align: middle;
  width: 22px;
  height: 22px;
  margin-left: 5px;
  background: rgba(255,255,255,.1);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  color: var(--muted);
  padding: 0;
  transition: transform .2s ease, background .15s;
  flex-shrink: 0;
}
.lead-toggle.open { transform: rotate(180deg); }
.lead-toggle:hover { background: rgba(255,255,255,.18); }
:root[data-theme="light"] .lead-toggle { background: rgba(0,0,0,.07); }
:root[data-theme="light"] .lead-toggle:hover { background: rgba(0,0,0,.13); }

.gradient-text {
  background: linear-gradient(120deg, #fff 0%, #cbd5ff 35%, #a5f3fc 70%, #c4b5fd 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

:root[data-theme="light"] .gradient-text {
  background: linear-gradient(120deg, #0a0e1a 0%, #4338ca 50%, #0891b2 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  width: fit-content;
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  color: var(--text-soft);
  background: var(--surface-glass);
  font-size: 0.83rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.eyebrow::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 14px var(--accent);
}

/* Center the eyebrow pill inside centered section headers
   (eyebrows inside cards stay left-aligned). */
.section-head .eyebrow {
  justify-self: center;
}

/* ============== buttons ============== */

.site-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 48px;
  padding: 0 22px;
  border: 1px solid var(--border-strong);
  border-radius: var(--r-pill);
  color: var(--text);
  background: var(--surface-glass);
  font-weight: 700;
  font-size: 0.95rem;
  line-height: 1;
  text-align: center;
  cursor: pointer;
  transition: transform var(--t-fast), background var(--t-fast),
    border-color var(--t-fast), box-shadow var(--t-mid);
}

.site-btn:hover {
  transform: translateY(-1px);
  border-color: var(--text-soft);
  background: rgba(255, 255, 255, 0.06);
}

:root[data-theme="light"] .site-btn:hover {
  background: rgba(15, 23, 42, 0.05);
}

.site-btn.primary {
  color: #fff;
  border: 1px solid transparent;
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-2) 100%);
  box-shadow: var(--glow-accent);
}

.site-btn.primary:hover {
  filter: brightness(1.06);
  box-shadow: 0 0 0 1px rgba(124, 92, 255, 0.6),
    0 32px 100px rgba(124, 92, 255, 0.32);
}

.site-btn.ghost {
  border-color: transparent;
  background: transparent;
}

.site-btn.sm {
  min-height: 38px;
  padding: 0 16px;
  font-size: 0.85rem;
}

.site-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.hero-ru-btns {
  display: inline-flex;
  gap: 12px;
  flex-wrap: wrap;
}

.hero-btn-tg {
  border-color: #2aabee;
  color: #2aabee !important;
}
.hero-btn-tg:hover {
  background: #2aabee;
  color: #fff !important;
  border-color: #2aabee;
}

.hero-btn-max {
  border-color: #0077ff;
  color: #0077ff !important;
}
.hero-btn-max:hover {
  background: #0077ff;
  color: #fff !important;
  border-color: #0077ff;
}

@media (max-width: 768px) {
  .hero-ru-btns {
    flex-basis: 100%;
    width: 100%;
  }
}

/* ============== header ============== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid var(--border);
  background: rgba(7, 8, 13, 0.72);
  backdrop-filter: blur(22px) saturate(150%);
  -webkit-backdrop-filter: blur(22px) saturate(150%);
}

:root[data-theme="light"] .site-header {
  background: rgba(255, 255, 255, 0.78);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 18px;
  min-height: 72px;
  position: relative;
}

.site-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-right: auto;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--text);
}

.site-brand img {
  display: block;
  width: 36px;
  height: 36px;
  border-radius: 10px;
  object-fit: cover;
  filter: invert(1);
}

:root[data-theme="light"] .site-brand img {
  filter: none;
}

.site-brand .brand-text {
  font-size: 1.1rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.site-menu {
  display: flex;
  align-items: center;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.site-menu > li {
  position: relative;
}

.site-menu a,
.site-menu .menu-trigger {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 14px;
  color: var(--text-soft);
  border-radius: 12px;
  background: transparent;
  border: 0;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: background var(--t-fast), color var(--t-fast);
}

.site-menu a:hover,
.site-menu .menu-trigger:hover,
.site-menu .menu-trigger[aria-expanded="true"] {
  color: var(--text);
  background: var(--surface-glass);
}

.site-menu .menu-trigger::after {
  content: "";
  width: 8px;
  height: 8px;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(45deg) translateY(-2px);
  margin-left: 4px;
  transition: transform var(--t-fast);
}

.site-menu .menu-trigger[aria-expanded="true"]::after {
  transform: rotate(-135deg) translateY(0);
}

.theme-toggle {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border: 1px solid var(--border);
  background: var(--surface-glass);
  border-radius: var(--r-pill);
  color: var(--text);
  cursor: pointer;
  transition: background var(--t-fast), border-color var(--t-fast);
}

.theme-toggle:hover {
  border-color: var(--border-strong);
}

.theme-toggle .icon-light {
  display: none;
}

:root[data-theme="light"] .theme-toggle .icon-dark {
  display: none;
}

:root[data-theme="light"] .theme-toggle .icon-light {
  display: block;
}

.site-menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid var(--border);
  border-radius: 12px;
  color: var(--text);
  background: var(--surface-glass);
  cursor: pointer;
  margin-left: auto;
}

/* mega menu */
.mega-menu {
  position: absolute;
  top: calc(100% + 12px);
  left: 50%;
  transform: translateX(-50%) translateY(-6px);
  display: none;
  width: max-content;
  max-width: min(92vw, 720px);
  padding: 22px;
  background: var(--surface-strong);
  border: 1px solid var(--border-strong);
  border-radius: var(--r-lg);
  box-shadow: var(--sh-lg);
  opacity: 0;
  pointer-events: none;
  z-index: 110;
  transition: transform var(--t-mid), opacity var(--t-mid);
}

.mega-menu.is-open {
  display: block;
  opacity: 1;
  pointer-events: auto;
  transform: translateX(-50%) translateY(0);
}

.mega-menu.right {
  left: auto;
  right: 0;
  transform: translateY(-6px);
}

.mega-menu.right.is-open {
  transform: translateY(0);
}

.mega-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4px 36px;
}

.mega-grid.compare {
  grid-template-columns: 1fr;
  gap: 2px;
  min-width: 280px;
}

.mega-section h6 {
  margin: 6px 12px 8px;
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  font-weight: 800;
  text-transform: uppercase;
  color: var(--dim);
}

.mega-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border-radius: 12px;
  color: var(--text-soft);
  font-weight: 600;
  font-size: 0.92rem;
  transition: background var(--t-fast), color var(--t-fast);
}

.mega-link:hover {
  color: var(--text);
  background: var(--surface-glass);
}

.mega-link.sub {
  padding: 7px 12px 7px 22px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--muted);
}

.mega-link.sub:hover {
  color: var(--text-soft);
}

.ai-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
  box-shadow: 0 0 12px currentColor;
}

.ai-dot.chatgpt { background: var(--c-chatgpt); color: var(--c-chatgpt); }
.ai-dot.claude { background: var(--c-claude); color: var(--c-claude); }
.ai-dot.gemini { background: var(--c-gemini); color: var(--c-gemini); }
.ai-dot.grok { background: var(--c-grok); color: var(--c-grok); }
.ai-dot.deepseek { background: var(--c-deepseek); color: var(--c-deepseek); }
.ai-dot.qwen { background: var(--c-qwen); color: var(--c-qwen); }
.ai-dot.llama { background: var(--c-llama); color: var(--c-llama); }
.ai-dot.kimi { background: var(--c-kimi); color: var(--c-kimi); }
.ai-dot.perplexity { background: var(--c-perplexity); color: var(--c-perplexity); }

/* ============== hero ============== */

.hero {
  position: relative;
  padding: clamp(56px, 9vw, 130px) 0 clamp(40px, 6vw, 80px);
  overflow: hidden;
}

.hero-orb {
  position: absolute;
  inset: -25% -10% auto -10%;
  height: 760px;
  pointer-events: none;
  background:
    radial-gradient(45% 55% at 30% 30%, rgba(124, 92, 255, 0.55), transparent 70%),
    radial-gradient(40% 50% at 70% 30%, rgba(56, 189, 248, 0.45), transparent 70%),
    radial-gradient(50% 60% at 50% 70%, rgba(244, 114, 182, 0.28), transparent 70%);
  filter: blur(40px);
  opacity: 0.7;
  z-index: 0;
}

.hero .site-container {
  position: relative;
  z-index: 1;
}

.hero-grid {
  display: grid;
  align-items: center;
  gap: clamp(34px, 6vw, 70px);
  grid-template-columns: minmax(0, 1.05fr) minmax(280px, 0.85fr);
}

.hero-copy {
  display: grid;
  gap: 22px;
}

.hero-copy .title-xl {
  letter-spacing: -0.06em;
}

.hero-meta {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 8px 14px 8px 8px;
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  background: var(--surface-glass);
  width: fit-content;
  font-size: 0.85rem;
  color: var(--muted);
}

.hero-meta .badge {
  padding: 4px 10px;
  border-radius: var(--r-pill);
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
  font-weight: 700;
  font-size: 0.74rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* hero chat preview */
.chat-preview {
  position: relative;
  padding: 18px;
  border-radius: var(--r-xl);
  border: 1px solid var(--border);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.06), rgba(255, 255, 255, 0.015)),
    var(--surface);
  box-shadow: var(--sh-lg);
  backdrop-filter: blur(22px);
}

.chat-preview-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.85rem;
}

.chat-preview-top .dots {
  display: flex;
  gap: 6px;
}

.chat-preview-top .dots span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.chat-preview-top .dots span:nth-child(1) { background: #fb7185; }
.chat-preview-top .dots span:nth-child(2) { background: #facc15; }
.chat-preview-top .dots span:nth-child(3) { background: #4ade80; }

.chat-preview .msg {
  width: fit-content;
  max-width: 88%;
  margin-top: 12px;
  padding: 12px 14px;
  border-radius: 16px;
  background: var(--surface-glass);
  color: var(--text-soft);
  font-size: 0.92rem;
  border: 1px solid var(--border);
}

.chat-preview .msg.user {
  margin-left: auto;
  background: linear-gradient(135deg, rgba(124, 92, 255, 0.18), rgba(56, 189, 248, 0.14));
  border-color: rgba(124, 92, 255, 0.35);
  color: var(--text);
}

.chat-preview-input {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-top: 16px;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 16px;
  background: rgba(0, 0, 0, 0.2);
  color: var(--muted);
  font-size: 0.9rem;
}

:root[data-theme="light"] .chat-preview-input {
  background: rgba(15, 23, 42, 0.04);
}

.chat-preview-input .send {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
}

/* ============== marquee ============== */

.marquee {
  position: relative;
  padding: 18px 0;
  overflow: hidden;
  border-block: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.02);
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 12%, #000 88%, transparent);
  mask-image: linear-gradient(90deg, transparent, #000 12%, #000 88%, transparent);
}

:root[data-theme="light"] .marquee {
  background: rgba(15, 23, 42, 0.02);
}

.marquee-track {
  display: flex;
  flex-wrap: nowrap;
  gap: 36px;
  width: max-content;
  animation: marquee-scroll 38s linear infinite;
}

.marquee-item {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 8px 16px;
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  color: var(--text-soft);
  background: var(--surface-glass);
  font-weight: 600;
  font-size: 0.92rem;
  white-space: nowrap;
}

@keyframes marquee-scroll {
  to {
    transform: translateX(-50%);
  }
}

/* ============== bento / cards ============== */

.bento-grid {
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(12, minmax(0, 1fr));
}

.bento-grid > * {
  grid-column: span 4;
}

.bento-grid > .span-6 { grid-column: span 6; }
.bento-grid > .span-8 { grid-column: span 8; }
.bento-grid > .span-12 { grid-column: span 12; }

.card {
  position: relative;
  padding: clamp(20px, 2vw, 28px);
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.06), rgba(255, 255, 255, 0.01)),
    var(--surface);
  box-shadow: var(--sh-md);
  backdrop-filter: blur(18px);
  transition: transform var(--t-mid), border-color var(--t-mid),
    box-shadow var(--t-mid);
}

:root[data-theme="light"] .card {
  background: var(--surface-strong);
}

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

.card.glow::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(
    280px 200px at var(--mx, 50%) var(--my, 0%),
    rgba(124, 92, 255, 0.18),
    transparent 60%
  );
  opacity: 0;
  transition: opacity var(--t-mid);
}

.card.glow:hover::before {
  opacity: 1;
}

.card.feature {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.card p,
.card li {
  color: var(--muted);
}

.icon-tile {
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  border-radius: 14px;
  color: #fff;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  font-weight: 800;
  font-size: 1.05rem;
}

.icon-tile.outline {
  color: var(--text);
  background: var(--surface-glass);
  border: 1px solid var(--border-strong);
}

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

/* ============== AI showcase grid ============== */

.ai-showcase {
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.ai-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 24px;
  border-radius: var(--r-lg);
  border: 1px solid var(--border);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.05), rgba(255, 255, 255, 0)),
    var(--surface);
  box-shadow: var(--sh-md);
  overflow: hidden;
  transition: transform var(--t-mid), border-color var(--t-mid),
    box-shadow var(--t-mid);
}

:root[data-theme="light"] .ai-card {
  background: var(--surface-strong);
}

.ai-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(
    340px 200px at 0% 0%,
    var(--ai-color, var(--accent)),
    transparent 60%
  );
  opacity: 0.14;
  pointer-events: none;
  transition: opacity var(--t-mid);
}

.ai-card:hover {
  transform: translateY(-4px);
  border-color: var(--ai-color, var(--accent-2));
  box-shadow: 0 20px 60px -20px var(--ai-color, var(--accent));
}

.ai-card:hover::before {
  opacity: 0.26;
}

.ai-card .ai-head {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
}

.ai-card .ai-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: var(--r-pill);
  border: 1px solid var(--border);
  color: var(--text-soft);
  background: var(--surface-glass);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  width: fit-content;
}

.ai-card .ai-desc {
  margin: 0;
  color: var(--muted);
  font-size: 0.93rem;
  flex: 1;
  display: -webkit-box;
  -webkit-line-clamp: 5;
  line-clamp: 5;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.ai-card .ai-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-top: 8px;
}

.ai-card .ai-foot a {
  color: var(--text-soft);
  font-weight: 700;
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.ai-card .ai-foot a:hover {
  color: var(--text);
}

.ai-card .ai-foot a::after {
  content: "→";
  transition: transform var(--t-fast);
}

.ai-card .ai-foot a:hover::after {
  transform: translateX(3px);
}

/* AI brand colors driving --ai-color */
.ai-card[data-ai="chatgpt"] { --ai-color: var(--c-chatgpt); }
.ai-card[data-ai="claude"] { --ai-color: var(--c-claude); }
.ai-card[data-ai="gemini"] { --ai-color: var(--c-gemini); }
.ai-card[data-ai="grok"] { --ai-color: var(--c-grok); }
.ai-card[data-ai="deepseek"] { --ai-color: var(--c-deepseek); }
.ai-card[data-ai="qwen"] { --ai-color: var(--c-qwen); }
.ai-card[data-ai="llama"] { --ai-color: var(--c-llama); }
.ai-card[data-ai="kimi"] { --ai-color: var(--c-kimi); }
.ai-card[data-ai="perplexity"] { --ai-color: var(--c-perplexity); }

/* ============== model rail (horizontal scroll) ============== */

.model-rail {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(280px, 320px);
  gap: 16px;
  overflow-x: auto;
  padding: 4px 4px 24px;
  scroll-snap-type: x mandatory;
  scrollbar-width: thin;
  scrollbar-color: var(--border-strong) transparent;
}

.model-rail::-webkit-scrollbar {
  height: 8px;
}

.model-rail::-webkit-scrollbar-thumb {
  background: var(--border-strong);
  border-radius: var(--r-pill);
}

.model-card {
  scroll-snap-align: start;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 22px;
  border-radius: var(--r-lg);
  border: 1px solid var(--border);
  background: var(--surface);
  transition: transform var(--t-mid), border-color var(--t-mid);
}

:root[data-theme="light"] .model-card {
  background: var(--surface-strong);
}

.model-card:hover {
  transform: translateY(-3px);
  border-color: var(--border-strong);
}

.model-card .pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: var(--r-pill);
  background: var(--surface-glass);
  border: 1px solid var(--border);
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  width: fit-content;
}

.model-card h3 {
  margin: 0;
  font-size: 1.2rem;
  letter-spacing: -0.025em;
}

.model-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.93rem;
  flex: 1;
}

.model-card .meta {
  display: grid;
  gap: 6px;
  padding-top: 10px;
  border-top: 1px solid var(--hairline);
  font-size: 0.82rem;
  color: var(--muted);
}

.model-card .meta span {
  display: flex;
  justify-content: space-between;
}

.model-card .meta span b {
  color: var(--text-soft);
  font-weight: 700;
}

/* ============== faq ============== */

.faq {
  display: grid;
  gap: 12px;
  max-width: 820px;
  margin-inline: auto;
}

.faq details {
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  background: var(--surface);
  overflow: hidden;
}

:root[data-theme="light"] .faq details {
  background: var(--surface-strong);
}

.faq summary {
  cursor: pointer;
  list-style: none;
  padding: 18px 22px;
  color: var(--text);
  font-weight: 700;
  font-size: 1rem;
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: center;
}

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

.faq summary::after {
  content: "+";
  width: 24px;
  height: 24px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--surface-glass);
  border: 1px solid var(--border);
  font-size: 1.1rem;
  font-weight: 600;
  flex-shrink: 0;
  transition: transform var(--t-fast);
}

.faq details[open] summary::after {
  transform: rotate(45deg);
}

.faq details p {
  margin: 0;
  padding: 0 22px 20px;
  color: var(--muted);
}

/* ============== check-list ============== */

.check-list {
  display: grid;
  gap: 12px;
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
}

.check-list li {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  color: var(--muted);
}

.check-list li::before {
  content: "";
  flex: 0 0 22px;
  height: 22px;
  border-radius: 50%;
  background:
    linear-gradient(135deg, var(--accent), var(--accent-2)) center/cover;
  position: relative;
  margin-top: 2px;
}

.check-list li::after {
  content: "";
  position: absolute;
  margin-left: -16px;
  margin-top: 8px;
  width: 8px;
  height: 4px;
  border-left: 2px solid #fff;
  border-bottom: 2px solid #fff;
  transform: rotate(-45deg);
}

/* ============== compare table ============== */

.compare-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 18px;
  margin-bottom: 18px;
}

.compare-side {
  position: relative;
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  background: var(--surface);
  display: grid;
  gap: 10px;
}

:root[data-theme="light"] .compare-side {
  background: var(--surface-strong);
}

.compare-side .head {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.4rem;
  letter-spacing: -0.025em;
}

.compare-side p {
  color: var(--muted);
  margin: 0;
}

.compare-table {
  width: 100%;
  border-collapse: collapse;
  border-radius: var(--r-lg);
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--surface);
}

:root[data-theme="light"] .compare-table {
  background: var(--surface-strong);
}

.compare-table th,
.compare-table td {
  padding: 16px 18px;
  text-align: left;
  border-bottom: 1px solid var(--hairline);
  font-size: 0.94rem;
  vertical-align: top;
}

.compare-table th {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
  background: var(--surface-glass);
  font-weight: 700;
}

.compare-table tr:last-child td {
  border-bottom: 0;
}

.compare-table tr td:first-child {
  font-weight: 700;
  color: var(--text);
  width: 28%;
}

.compare-table td {
  color: var(--text-soft);
}

/* ============== model spec table ============== */

.spec-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 14px;
}

.spec-item {
  padding: 16px 18px;
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  background: var(--surface);
  display: grid;
  gap: 4px;
}

:root[data-theme="light"] .spec-item {
  background: var(--surface-strong);
}

.spec-item .lbl {
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  font-weight: 700;
}

.spec-item .val {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
}

/* ============== footer ============== */

.site-footer {
  position: relative;
  z-index: 1;
  margin-top: clamp(40px, 6vw, 80px);
  border-top: 1px solid var(--border);
  background: rgba(7, 8, 13, 0.7);
  backdrop-filter: blur(18px);
}

:root[data-theme="light"] .site-footer {
  background: rgba(255, 255, 255, 0.7);
}

.footer-top {
  padding: clamp(48px, 6vw, 80px) 0 36px;
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(260px, 1.4fr) repeat(4, minmax(0, 1fr));
  gap: 32px;
}

.footer-grid h5 {
  margin: 0 0 14px;
  color: var(--dim);
  font-size: 0.74rem;
  font-weight: 800;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.footer-grid ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.footer-grid a {
  color: var(--muted);
  font-size: 0.92rem;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: color var(--t-fast);
}

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

.footer-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 18px;
}

.footer-logo img {
  width: 36px;
  height: 36px;
  border-radius: 10px;
}

.footer-logo .brand-text {
  font-size: 1.05rem;
  font-weight: 800;
}

.footer-grid p {
  color: var(--muted);
  font-size: 0.92rem;
  margin: 0 0 18px;
}

.store-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.store-links img {
  max-height: 40px;
  border-radius: 10px;
}

.lang-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 36px;
  padding-top: 36px;
  border-top: 1px solid var(--hairline);
}

.lang-grid a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 12px;
  color: var(--muted);
  font-size: 0.85rem;
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  background: var(--surface-glass);
  transition: color var(--t-fast), border-color var(--t-fast);
}

.lang-grid a:hover {
  color: var(--text);
  border-color: var(--border-strong);
}

.lang-grid .flag {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  object-fit: cover;
}

.footer-bottom {
  border-top: 1px solid var(--hairline);
  padding: 22px 0;
}

.footer-bottom-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  color: var(--muted);
  font-size: 0.85rem;
}

.footer-bottom-inner p,
.footer-bottom-inner span {
  margin: 0;
}

/* ============== model hero (brand pages) ============== */

.brand-hero {
  position: relative;
  padding: clamp(72px, 9vw, 130px) 0 clamp(48px, 6vw, 80px);
  text-align: center;
}

.brand-hero .lead {
  max-width: 760px;
  margin: 0 auto;
}

.brand-hero .ai-tag {
  margin: 0 auto 18px;
}

.brand-hero h1 {
  margin: 0 0 18px;
}

/* ============== ad wrap ============== */

.ad-wrap {
  display: flex;
  justify-content: center;
  max-width: 100%;
  overflow-x: auto;
}

/* ============== chat-frame fallback ============== */

.chat-frame {
  display: block;
  width: 100%;
  height: 100vh;
  border: 0;
}

/* ============== prose (legal) ============== */

.prose {
  max-width: 880px;
  margin-inline: auto;
}

.prose h2,
.prose h3 {
  margin: 1.6em 0 0.6em;
  color: var(--text);
}

.prose p,
.prose li {
  color: var(--muted);
  line-height: 1.75;
}

.prose a {
  color: var(--accent-2);
  text-decoration: underline;
  text-decoration-color: rgba(56, 189, 248, 0.45);
}

/* ============== reveal-on-scroll ============== */

.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 600ms ease, transform 600ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.reveal.in {
  opacity: 1;
  transform: none;
}

/* ============== responsive ============== */

@media (max-width: 1100px) {
  .ai-showcase {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 991px) {
  .site-nav {
    flex-wrap: wrap;
    min-height: auto;
    padding: 14px 0;
  }

  .site-menu-toggle {
    display: inline-grid;
    place-items: center;
  }

  .site-menu {
    display: none;
    order: 99;
    flex-basis: 100%;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    padding: 14px 0 8px;
  }

  .site-menu.is-open {
    display: flex;
  }

  .site-menu > li {
    width: 100%;
  }

  .site-menu a,
  .site-menu .menu-trigger {
    width: 100%;
    justify-content: space-between;
    padding: 12px 14px;
  }

  .mega-menu {
    position: static;
    transform: none;
    display: none;
    width: 100%;
    max-width: 100%;
    margin-top: 4px;
    padding: 12px;
    box-shadow: none;
    background: var(--surface-glass);
    opacity: 1;
    pointer-events: auto;
  }

  .mega-menu.right {
    transform: none;
  }

  .mega-menu.is-open {
    display: block;
    transform: none;
  }

  .mega-grid {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .site-nav > .site-btn,
  .site-nav > .theme-toggle {
    display: none;
  }

  .hero-grid,
  .ai-showcase {
    grid-template-columns: 1fr;
  }

  .chat-preview {
    display: none;
  }

  .bento-grid > * {
    grid-column: span 12;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }

  .compare-shell {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 575px) {
  .site-container {
    width: min(100% - 24px, var(--container));
  }

  .hero-grid {
    gap: 28px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
  }

  .footer-bottom-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .ai-showcase {
    grid-template-columns: 1fr;
  }
}