/* AI 搜题 official download page */
:root {
  --bg: #070a10;
  --bg-2: #0a0f19;
  --surface: rgba(16, 23, 37, 0.72);
  --surface-solid: #0f1624;
  --surface-2: #121b2d;
  --text: #eef2ff;
  --muted: #98a5c2;
  --soft: #c8d2e8;
  --line: rgba(148, 163, 197, 0.16);
  --line-strong: rgba(148, 163, 197, 0.3);
  --brand: #6c8cff;
  --brand-2: #8b5cf6;
  --cyan: #4fd1ff;
  --green: #43d99a;
  --warn: #ffb86b;
  --shadow: 0 30px 80px rgba(0, 0, 0, 0.45);
  --nav-bg: rgba(7, 10, 16, 0.7);
  --term-bg: #060a12;
  --term-text: #c9d6f2;
  --radius: 22px;
  --max: 1140px;
}

html[data-theme="light"] {
  --bg: #f5f7ff;
  --bg-2: #eef2ff;
  --surface: rgba(255, 255, 255, 0.8);
  --surface-solid: #ffffff;
  --surface-2: #f0f4ff;
  --text: #101728;
  --muted: #5a6684;
  --soft: #33405e;
  --line: rgba(16, 23, 40, 0.1);
  --line-strong: rgba(16, 23, 40, 0.2);
  --brand: #2f5bea;
  --brand-2: #7c3aed;
  --cyan: #0284c7;
  --green: #0e9f6e;
  --warn: #b45309;
  --shadow: 0 30px 70px rgba(44, 64, 120, 0.14);
  --nav-bg: rgba(245, 247, 255, 0.78);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; overflow-x: hidden; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Noto Sans CJK SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; }
code, pre { font-family: "SFMono-Regular", "JetBrains Mono", Consolas, "Liberation Mono", monospace; }
::selection { background: rgba(108, 140, 255, 0.35); }

.skip-link {
  position: fixed; left: 16px; top: -60px; z-index: 100;
  padding: 10px 16px; border-radius: 10px; background: var(--brand); color: #fff;
  transition: top 0.2s;
}
.skip-link:focus { top: 16px; }

.bg { position: fixed; inset: 0; z-index: -1; overflow: hidden; pointer-events: none; }
.bg-grid {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 68px 68px;
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 20%, transparent 75%);
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 20%, transparent 75%);
  opacity: 0.55;
}
.orb { position: absolute; border-radius: 50%; filter: blur(80px); opacity: 0.45; }
.orb-a { width: 520px; height: 520px; top: -180px; left: -120px; background: rgba(91, 124, 255, 0.32); }
.orb-b { width: 460px; height: 460px; top: 260px; right: -160px; background: rgba(139, 92, 246, 0.25); }
.orb-c { width: 420px; height: 420px; top: 1400px; left: 20%; background: rgba(79, 209, 255, 0.13); }

.container { width: min(var(--max), calc(100% - 40px)); margin: 0 auto; min-width: 0; max-width: 100%; }
.hero-visual, .deepseek-card, .terminal, .terminal pre, .download-card, .release-card, .shots { min-width: 0; max-width: 100%; }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 9px;
  border: 1px solid transparent; border-radius: 14px;
  padding: 12px 20px; font-weight: 650; font-size: 14.5px; line-height: 1;
  cursor: pointer; transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s, background 0.2s;
  white-space: nowrap; -webkit-tap-highlight-color: transparent;
}
.btn:hover { transform: translateY(-1px); }
.btn:focus-visible { outline: 3px solid rgba(108, 140, 255, 0.4); outline-offset: 3px; }
.btn-primary {
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  color: #fff;
  box-shadow: 0 12px 30px rgba(80, 105, 255, 0.32);
}
.btn-primary:hover { box-shadow: 0 16px 38px rgba(80, 105, 255, 0.42); }
.btn-ghost {
  background: var(--surface);
  border-color: var(--line-strong);
  color: var(--text);
  backdrop-filter: blur(12px);
}
.btn-ghost:hover { border-color: var(--brand); }
.btn-sm { padding: 10px 15px; border-radius: 12px; font-size: 13px; }
.btn-lg { padding: 15px 24px; border-radius: 16px; font-size: 15.5px; }
.btn-icon { width: 18px; height: 18px; flex: 0 0 auto; }
.icon-btn {
  width: 40px; height: 40px; border-radius: 12px; border: 1px solid var(--line);
  background: var(--surface); display: inline-flex; align-items: center; justify-content: center;
  cursor: pointer; color: var(--soft); transition: border-color 0.2s, color 0.2s, background 0.2s;
}
.icon-btn:hover { border-color: var(--brand); color: var(--brand); }
.icon-btn svg { width: 19px; height: 19px; }
.text-link { color: var(--brand); font-size: 14px; font-weight: 600; display: inline-flex; gap: 6px; align-items: center; }
.text-link:hover { text-decoration: underline; }
.dot-sep { width: 3px; height: 3px; border-radius: 50%; background: var(--line-strong); }

/* ---------- nav ---------- */
.nav {
  position: fixed; inset: 0 0 auto 0; z-index: 50; max-width: 100%;
  background: var(--nav-bg); backdrop-filter: blur(18px); -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid transparent; transition: border-color 0.25s, box-shadow 0.25s;
}
.nav.scrolled { border-bottom-color: var(--line); box-shadow: 0 10px 40px rgba(0, 0, 0, 0.12); }
.nav-inner { height: 72px; display: flex; align-items: center; justify-content: space-between; gap: 24px; min-width: 0; max-width: 100%; }
.brand, .nav-actions { min-width: 0; max-width: 100%; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 750; letter-spacing: -0.02em; }
.brand-mark {
  width: 38px; height: 38px; border-radius: 12px; display: inline-flex; align-items: center; justify-content: center;
  color: #fff; background: linear-gradient(135deg, #2f5bea, #7c5cff);
  box-shadow: 0 8px 22px rgba(80, 105, 255, 0.35); flex: 0 0 auto;
}
.brand-mark svg { width: 26px; height: 26px; }
.brand-text { font-size: 17px; }
.brand-text em {
  font-style: normal; font-size: 10px; letter-spacing: 0.12em; font-weight: 700;
  color: var(--brand); border: 1px solid rgba(108, 140, 255, 0.35); border-radius: 6px;
  padding: 2px 5px; margin-left: 4px; vertical-align: 2px;
}
.nav-links { display: flex; align-items: center; gap: 30px; font-size: 14px; color: var(--muted); }
.nav-links a { transition: color 0.2s; }
.nav-links a:hover { color: var(--text); }
.nav-actions { display: flex; align-items: center; gap: 10px; }
.nav-toggle { display: none; }
.icon-moon { display: none; }
html[data-theme="light"] .icon-sun { display: none; }
html[data-theme="light"] .icon-moon { display: block; }

/* ---------- hero ---------- */
.hero { padding: 146px 0 56px; position: relative; }
.hero-inner { display: grid; grid-template-columns: 1.06fr 0.94fr; align-items: center; gap: 44px; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px; font-size: 12px; letter-spacing: 0.06em;
  color: var(--soft); border: 1px solid var(--line); background: var(--surface);
  padding: 7px 12px; border-radius: 999px; backdrop-filter: blur(12px);
}
.pulse-dot {
  width: 7px; height: 7px; border-radius: 50%; background: var(--green);
  box-shadow: 0 0 0 0 rgba(67, 217, 154, 0.5); animation: pulse 2s infinite; flex: 0 0 auto;
}
@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(67, 217, 154, 0.45); }
  70% { box-shadow: 0 0 0 8px rgba(67, 217, 154, 0); }
  100% { box-shadow: 0 0 0 0 rgba(67, 217, 154, 0); }
}
.hero h1 {
  margin: 22px 0 0; font-size: clamp(44px, 5.8vw, 76px); line-height: 1.06;
  letter-spacing: -0.045em; font-weight: 800;
}
.gradient-text {
  background: linear-gradient(100deg, var(--brand) 0%, var(--cyan) 45%, var(--brand-2) 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.lead { margin: 24px 0 0; max-width: 570px; color: var(--muted); font-size: 16.5px; line-height: 1.9; }
.lead strong { color: var(--soft); font-weight: 600; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }
.hero-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-top: 18px; color: var(--muted); font-size: 12.5px; }
.trust { display: flex; flex-wrap: wrap; gap: 8px 18px; list-style: none; padding: 0; margin: 22px 0 0; color: var(--muted); font-size: 12.5px; }
.trust li { display: flex; align-items: center; gap: 6px; }
.trust li::before { content: "✓"; color: var(--green); font-weight: 800; }

.hero-visual { position: relative; min-height: 640px; display: flex; align-items: center; justify-content: center; }
.hero-glow {
  position: absolute; width: 430px; height: 520px; border-radius: 50%;
  background: radial-gradient(circle, rgba(91, 124, 255, 0.4), transparent 66%);
  filter: blur(30px); transform: translateY(-10px);
}
.phone {
  position: relative; width: 296px; height: 636px; border-radius: 44px;
  border: 9px solid #1a2336; background: #080c14;
  box-shadow: 0 50px 100px rgba(0, 0, 0, 0.55), inset 0 0 0 1px rgba(255, 255, 255, 0.06);
  overflow: hidden;
}
.phone-hero { transform: rotate(1.6deg); transition: transform 0.5s ease; z-index: 2; }
.phone-hero:hover { transform: rotate(0deg) translateY(-6px); }
.phone-screen { display: block; width: 100%; height: 100%; overflow: hidden; border-radius: 34px; background: #0e1016; }
.phone-screen img { width: 100%; height: 100%; object-fit: cover; object-position: top center; }
.phone-notch {
  position: absolute; top: 9px; left: 50%; transform: translateX(-50%);
  width: 88px; height: 20px; border-radius: 20px; background: #1a2336; z-index: 3;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.04);
}
.float-card {
  position: absolute; z-index: 4; display: flex; align-items: center; gap: 10px;
  background: rgba(14, 21, 35, 0.86); border: 1px solid rgba(148, 163, 197, 0.22);
  border-radius: 14px; padding: 10px 13px; box-shadow: 0 18px 50px rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(14px); font-size: 12px;
}
html[data-theme="light"] .float-card { background: rgba(255, 255, 255, 0.9); }
.float-card b { display: block; font-size: 12.5px; font-weight: 650; }
.float-card small { display: block; color: var(--muted); font-size: 10.5px; margin-top: 2px; }
.float-thinking { top: 16%; left: -44px; }
.float-format { bottom: 17%; right: -48px; }
.float-model { bottom: 36%; left: -64px; }
.mini-badge {
  width: 30px; height: 30px; border-radius: 9px; display: inline-flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, rgba(108, 140, 255, 0.25), rgba(139, 92, 246, 0.25));
  color: var(--brand); font-weight: 800; font-size: 13px; flex: 0 0 auto;
}
.mini-blue { background: linear-gradient(135deg, #2f5bea, #7c5cff); color: #fff; font-size: 11px; }

.chip-row { display: flex; flex-wrap: wrap; justify-content: center; gap: 9px; margin-top: 66px; }
.chip {
  color: var(--muted); font-size: 12px; border: 1px solid var(--line);
  background: var(--surface); border-radius: 999px; padding: 7px 13px;
  backdrop-filter: blur(10px);
}

/* ---------- sections ---------- */
.section { padding: 108px 0; scroll-margin-top: 86px; }
.section-head { max-width: 760px; margin-bottom: 42px; }
.kicker { font-size: 11px; letter-spacing: 0.2em; font-weight: 750; color: var(--brand); text-transform: uppercase; }
.section-head h2 {
  margin: 14px 0 0; font-size: clamp(32px, 4.4vw, 50px); line-height: 1.14;
  letter-spacing: -0.035em; font-weight: 780;
}
.section-head p { margin: 16px 0 0; max-width: 640px; color: var(--muted); font-size: 15.5px; line-height: 1.85; }

/* ---------- features ---------- */
.feature-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 15px; }
.feature-card {
  position: relative; padding: 24px 22px 22px; border-radius: 20px;
  border: 1px solid var(--line); background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.035), transparent 45%),
    var(--surface);
  backdrop-filter: blur(14px);
  transition: transform 0.25s ease, border-color 0.25s, background 0.25s;
  overflow: hidden;
}
html[data-theme="light"] .feature-card { background: linear-gradient(180deg, rgba(47, 91, 234, 0.04), transparent 50%), var(--surface-solid); }
.feature-card:hover { transform: translateY(-5px); border-color: rgba(108, 140, 255, 0.45); }
.feature-card::after {
  content: ""; position: absolute; width: 140px; height: 140px; right: -70px; top: -70px; border-radius: 50%;
  background: radial-gradient(circle, rgba(108, 140, 255, 0.2), transparent 70%); opacity: 0; transition: opacity 0.3s;
}
.feature-card:hover::after { opacity: 1; }
.feature-icon {
  width: 44px; height: 44px; border-radius: 13px; display: inline-flex; align-items: center; justify-content: center;
  color: var(--brand); background: rgba(108, 140, 255, 0.12); border: 1px solid rgba(108, 140, 255, 0.2);
  margin-bottom: 16px;
}
.feature-icon svg { width: 23px; height: 23px; }
.feature-card h3 { margin: 0 0 7px; font-size: 16.5px; letter-spacing: -0.01em; }
.feature-card p { margin: 0; color: var(--muted); font-size: 13.2px; line-height: 1.75; }

/* ---------- showcase ---------- */
.showcase { background: var(--bg-2); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.shots { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; align-items: end; }
.shot { margin: 0; text-align: center; }
.shot-btn { display: block; width: 100%; border: 0; background: none; padding: 0; cursor: zoom-in; }
.phone-shot {
  width: min(264px, 100%); height: auto; aspect-ratio: 296 / 636; margin: 0 auto;
  border-width: 7px; border-radius: 36px; box-shadow: 0 30px 70px rgba(0, 0, 0, 0.38);
  transform: rotate(-1.2deg); transition: transform 0.35s ease, box-shadow 0.35s;
}
.shot:nth-child(2) .phone-shot { transform: translateY(-18px); }
.shot:nth-child(3) .phone-shot { transform: rotate(1.2deg); }
.shot-btn:hover .phone-shot { transform: translateY(-10px) rotate(0deg); box-shadow: 0 38px 90px rgba(0, 0, 0, 0.5); }
.phone-shot .phone-screen { border-radius: 28px; }
.shot figcaption { margin-top: 18px; display: flex; flex-direction: column; gap: 4px; }
.shot figcaption b { font-size: 14.5px; }
.shot figcaption span { color: var(--muted); font-size: 12px; }

/* ---------- deepseek ---------- */
.deepseek-card {
  position: relative; display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 44px; align-items: center;
  padding: 46px; border-radius: 28px; border: 1px solid var(--line);
  background:
    radial-gradient(ellipse 60% 80% at 0% 0%, rgba(108, 140, 255, 0.18), transparent 60%),
    radial-gradient(ellipse 50% 70% at 100% 100%, rgba(139, 92, 246, 0.15), transparent 60%),
    var(--surface);
  overflow: hidden;
}
.deepseek-copy h2 { margin: 14px 0 0; font-size: clamp(30px, 3.8vw, 44px); line-height: 1.14; letter-spacing: -0.035em; }
.deepseek-copy p { color: var(--muted); font-size: 15px; line-height: 1.85; margin: 16px 0 0; }
.check-list { list-style: none; padding: 0; margin: 22px 0 24px; display: grid; gap: 10px; }
.check-list li { position: relative; padding-left: 26px; color: var(--soft); font-size: 13.5px; }
.check-list li::before {
  content: "✓"; position: absolute; left: 0; top: 0; color: var(--green); font-weight: 800;
  width: 18px; height: 18px; border-radius: 50%; background: rgba(67, 217, 154, 0.12);
  display: inline-flex; align-items: center; justify-content: center; font-size: 11px;
}
.terminal {
  background: var(--term-bg); color: var(--term-text); border: 1px solid rgba(148, 163, 197, 0.2);
  border-radius: 18px; overflow: hidden; box-shadow: 0 26px 60px rgba(0, 0, 0, 0.35);
}
.terminal-bar { display: flex; align-items: center; gap: 6px; padding: 11px 14px; border-bottom: 1px solid rgba(148, 163, 197, 0.14); }
.terminal-bar span { width: 9px; height: 9px; border-radius: 50%; background: #ff6b6b; }
.terminal-bar span:nth-child(2) { background: #ffd166; }
.terminal-bar span:nth-child(3) { background: #43d99a; }
.terminal-bar em { margin-left: 8px; font-style: normal; font-size: 10.5px; color: #7f90b3; letter-spacing: 0.06em; }
.terminal pre { margin: 0; padding: 18px; overflow-x: auto; font-size: 11.6px; line-height: 1.75; }
.t-muted { color: #7f90b3; }
.t-key { color: #9db2ff; }
.t-str { color: #7ee2b8; }
.t-bool { color: #ffb86b; }
.terminal-foot { padding: 10px 14px; border-top: 1px solid rgba(148, 163, 197, 0.14); color: #7f90b3; font-size: 11px; display: flex; align-items: center; gap: 8px; }

/* ---------- update ---------- */
.update-grid { display: grid; grid-template-columns: 0.9fr 1.1fr; gap: 28px; align-items: start; }
.update-grid.single { grid-template-columns: minmax(0, 720px); justify-content: center; }
.steps { list-style: none; padding: 0; margin: 0; display: grid; gap: 22px; }
.steps li { display: flex; gap: 16px; align-items: flex-start; }
.steps li > span {
  width: 38px; height: 38px; flex: 0 0 auto; border-radius: 12px; display: inline-flex; align-items: center; justify-content: center;
  font-size: 12px; font-weight: 750; color: var(--brand); background: rgba(108, 140, 255, 0.12); border: 1px solid rgba(108, 140, 255, 0.22);
}
.steps b { display: block; font-size: 15.5px; margin-top: 4px; }
.steps p { margin: 4px 0 0; color: var(--muted); font-size: 13.2px; line-height: 1.75; }
.steps code { background: var(--surface-2); border: 1px solid var(--line); border-radius: 6px; padding: 2px 6px; font-size: 11.5px; }
.release-card {
  border: 1px solid rgba(108, 140, 255, 0.28); border-radius: 24px; padding: 26px;
  background:
    radial-gradient(ellipse 70% 80% at 100% 0%, rgba(108, 140, 255, 0.16), transparent 60%),
    var(--surface-solid);
  box-shadow: var(--shadow);
}
.release-top { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.status { display: inline-flex; align-items: center; gap: 7px; color: var(--muted); font-size: 11.5px; }
.release-version { font-size: 44px; font-weight: 800; letter-spacing: -0.04em; margin-top: 12px; }
.release-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 9px; color: var(--muted); font-size: 12.5px; margin-top: 2px; }
.changelog { list-style: none; padding: 0; margin: 20px 0 22px; display: grid; gap: 8px; }
.changelog li { position: relative; padding-left: 17px; color: var(--soft); font-size: 13.2px; }
.changelog li::before { content: ""; position: absolute; left: 0; top: 8px; width: 5px; height: 5px; border-radius: 50%; background: var(--brand); }
.release-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 16px; }

/* ---------- download ---------- */
.download-card {
  display: grid; grid-template-columns: 1.35fr 0.65fr; gap: 36px; padding: 46px;
  border-radius: 30px; color: #fff;
  background:
    radial-gradient(ellipse 60% 100% at 0% 0%, rgba(255, 255, 255, 0.22), transparent 55%),
    linear-gradient(135deg, #2f5bea 0%, #5b52e8 48%, #8b3fd6 100%);
  box-shadow: 0 40px 100px rgba(60, 70, 220, 0.32);
  position: relative; overflow: hidden;
}
.download-card::after {
  content: ""; position: absolute; width: 360px; height: 360px; right: -130px; bottom: -160px;
  border-radius: 50%; border: 1px solid rgba(255, 255, 255, 0.18);
}
.download-card .kicker { color: rgba(255, 255, 255, 0.7); }
.download-card h2 { margin: 12px 0 0; font-size: clamp(30px, 4vw, 46px); letter-spacing: -0.035em; line-height: 1.1; }
.download-card p { color: rgba(255, 255, 255, 0.78); font-size: 14.5px; line-height: 1.8; margin: 14px 0 0; max-width: 600px; }
.download-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 26px; }
.download-card .btn-primary { background: #fff; color: #1a2350; box-shadow: 0 14px 34px rgba(0, 0, 0, 0.22); }
.download-card .btn-ghost { background: rgba(255, 255, 255, 0.1); border-color: rgba(255, 255, 255, 0.3); color: #fff; }
.download-meta { display: flex; flex-wrap: wrap; gap: 10px; color: rgba(255, 255, 255, 0.72); font-size: 12.5px; margin-top: 16px; }
.download-meta .dot-sep { background: rgba(255, 255, 255, 0.4); }
.sha-line { font-size: 11px; color: rgba(255, 255, 255, 0.62); margin-top: 16px; word-break: break-all; }
.sha-line code { color: rgba(255, 255, 255, 0.82); background: rgba(0, 0, 0, 0.2); border: 1px solid rgba(255, 255, 255, 0.14); border-radius: 6px; padding: 3px 7px; font-size: 10.5px; }
.download-side { background: rgba(7, 10, 20, 0.22); border: 1px solid rgba(255, 255, 255, 0.16); border-radius: 18px; padding: 22px; backdrop-filter: blur(10px); }
.download-side h3 { margin: 0 0 12px; font-size: 14px; }
.download-side ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 9px; }
.download-side li { position: relative; padding-left: 18px; color: rgba(255, 255, 255, 0.82); font-size: 12.5px; }
.download-side li::before { content: "✓"; position: absolute; left: 0; color: rgba(255, 255, 255, 0.65); }
.download-side .tiny { margin-top: 16px; font-size: 11px; color: rgba(255, 255, 255, 0.6); }
.download-side a { color: #fff; text-decoration: underline; }

/* ---------- faq ---------- */
.faq-list { max-width: 820px; border-top: 1px solid var(--line); }
.faq-list details { border-bottom: 1px solid var(--line); padding: 4px 0; }
.faq-list summary {
  cursor: pointer; list-style: none; padding: 18px 34px 18px 0; position: relative;
  font-weight: 600; font-size: 15px;
}
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: "+"; position: absolute; right: 4px; top: 16px; color: var(--muted); font-size: 20px; line-height: 1; transition: transform 0.2s; }
.faq-list details[open] summary::after { content: "−"; }
.faq-list p { margin: 0 0 18px; color: var(--muted); font-size: 13.8px; line-height: 1.85; max-width: 720px; }
.faq-list code { background: var(--surface-2); border: 1px solid var(--line); border-radius: 5px; padding: 2px 5px; font-size: 12px; }

/* ---------- footer ---------- */
.footer { border-top: 1px solid var(--line); padding: 42px 0 36px; background: var(--bg-2); }
.footer-inner { display: flex; flex-wrap: wrap; align-items: center; gap: 24px 40px; }
.footer-brand { display: flex; align-items: center; gap: 12px; }
.footer-brand b { display: block; font-size: 15px; }
.footer-brand span { display: block; color: var(--muted); font-size: 11.5px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 18px; color: var(--muted); font-size: 12.5px; margin-left: auto; }
.footer-links a:hover { color: var(--text); }
.copyright { width: 100%; color: var(--muted); font-size: 11.5px; margin: 0; }

/* ---------- mobile bar / lightbox ---------- */
.mobile-bar {
  display: none; position: fixed; left: 0; right: 0; bottom: 0; z-index: 45;
  max-width: 100%; align-items: center; justify-content: space-between; gap: 14px;
  padding: 10px 16px calc(10px + env(safe-area-inset-bottom));
  background: var(--nav-bg); backdrop-filter: blur(18px); border-top: 1px solid var(--line);
}
.mobile-bar b { display: block; font-size: 13px; }
.mobile-bar span { display: block; color: var(--muted); font-size: 11px; }
.lightbox {
  position: fixed; inset: 0; z-index: 80; background: rgba(3, 6, 12, 0.9);
  display: grid; place-items: center; padding: 24px; backdrop-filter: blur(8px);
}
.lightbox[hidden] { display: none; }
.lightbox img { max-width: min(92vw, 560px); max-height: 90vh; border-radius: 22px; box-shadow: 0 40px 100px rgba(0, 0, 0, 0.6); }
.lightbox-close {
  position: absolute; top: 16px; right: 18px; width: 42px; height: 42px; border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.2); background: rgba(255, 255, 255, 0.08); color: #fff;
  font-size: 24px; line-height: 1; cursor: pointer;
}

/* ---------- reveal ---------- */
.reveal { opacity: 0; transform: translateY(20px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
  .reveal { opacity: 1; transform: none; }
}

/* ---------- responsive ---------- */
@media (max-width: 1040px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .hero-inner { grid-template-columns: 1fr; gap: 20px; }
  .hero-copy { max-width: 720px; }
  .hero-visual { min-height: 660px; margin-top: 14px; }
  .nav-links { gap: 20px; }
}
@media (max-width: 860px) {
  .nav-links {
    position: absolute; top: 72px; left: 20px; right: 20px; display: none;
    flex-direction: column; align-items: stretch; gap: 4px; padding: 12px;
    background: var(--surface-solid); border: 1px solid var(--line); border-radius: 16px;
    box-shadow: var(--shadow);
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 11px 12px; border-radius: 10px; }
  .nav-links a:hover { background: var(--surface-2); }
  .nav-toggle { display: inline-flex; }
  .nav-download { display: none; }
  .deepseek-card { grid-template-columns: 1fr; padding: 30px; gap: 28px; }
  .update-grid { grid-template-columns: 1fr; }
  .download-card { grid-template-columns: 1fr; padding: 32px; }
  .download-side { max-width: 520px; }
  .shots {
    display: flex; gap: 18px; overflow-x: auto; scroll-snap-type: x mandatory;
    padding: 4px 4px 16px; -webkit-overflow-scrolling: touch;
  }
  .shot { flex: 0 0 250px; scroll-snap-align: center; }
  .shot:nth-child(2) .phone-shot { transform: none; }
  .phone-shot { width: 250px; }
}
@media (max-width: 640px) {
  body { padding-bottom: 76px; }
  .container { width: calc(100% - 32px); }
  .nav-inner { height: 64px; }
  .nav-links { top: 64px; left: 16px; right: 16px; }
  .hero { padding: 118px 0 28px; }
  .hero h1 { font-size: clamp(40px, 13vw, 58px); }
  .lead { font-size: 15px; }
  .hero-cta .btn { flex: 1 1 100%; }
  .hero-visual { min-height: 570px; }
  .hero-glow { width: 320px; height: 440px; }
  .phone { width: 258px; height: 556px; border-width: 8px; border-radius: 38px; }
  .phone-screen { border-radius: 29px; }
  .float-thinking { left: -12px; top: 12%; }
  .float-format { right: -10px; bottom: 12%; }
  .float-model { left: -16px; bottom: 30%; }
  .float-card { padding: 8px 10px; font-size: 11px; }
  .float-card small { display: none; }
  .chip-row { margin-top: 36px; justify-content: flex-start; }
  .section { padding: 76px 0; }
  .section-head { margin-bottom: 30px; }
  .section-head h2 { font-size: clamp(30px, 8.5vw, 42px); }
  .feature-grid { grid-template-columns: 1fr; }
  .deepseek-card { padding: 24px; border-radius: 22px; }
  .terminal pre { font-size: 10.5px; padding: 14px; }
  .release-card { padding: 22px; }
  .release-version { font-size: 38px; }
  .download-card { padding: 26px 22px; border-radius: 24px; }
  .download-card .btn { width: 100%; }
  .download-side { padding: 18px; }
  .faq-list summary { font-size: 14px; }
  .footer-inner { align-items: flex-start; }
  .footer-links { margin-left: 0; }
  .mobile-bar { display: flex; }
  .lightbox { padding: 12px; }
}
@media (max-width: 380px) {
  .brand-text em { display: none; }
  .float-model { display: none; }
}