:root {
  --bg: #f6fbff;
  --card: rgba(255,255,255,.88);
  --text: #142033;
  --muted: #667085;
  --line: rgba(20,32,51,.1);
  --orange: #ff6b12;
  --orange2: #ff8a00;
  --yellow: #ffd21e;
  --blue: #0b8fff;
  --shadow: 0 24px 70px rgba(18,38,63,.12);
  --radius: 28px;
  --nav-bg: rgba(248,253,255,.76);
  --soft: rgba(255,255,255,.65);
  --soft2: #f8fafc;
  --dark-card: #1f2329;
}

html[data-theme="dark"] {
  --bg: #0f172a;
  --card: rgba(24,32,48,.88);
  --text: #f8fafc;
  --muted: #94a3b8;
  --line: rgba(255,255,255,.12);
  --shadow: 0 24px 70px rgba(0,0,0,.35);
  --nav-bg: rgba(15,23,42,.78);
  --soft: rgba(255,255,255,.06);
  --soft2: rgba(255,255,255,.06);
  --dark-card: #111827;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 12% 8%, rgba(255,210,30,.35), transparent 34%),
    radial-gradient(circle at 86% 16%, rgba(30,150,255,.18), transparent 30%),
    linear-gradient(180deg,#f8fdff 0%,#fffaf1 46%,#f7fbff 100%);
  transition: background .2s ease, color .2s ease;
}

html[data-theme="dark"] body {
  background:
    radial-gradient(circle at 12% 8%, rgba(255,210,30,.16), transparent 34%),
    radial-gradient(circle at 86% 16%, rgba(30,150,255,.18), transparent 30%),
    linear-gradient(180deg,#0f172a 0%,#111827 48%,#0b1120 100%);
}

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

.container { width: min(1180px, calc(100% - 36px)); margin: 0 auto; }

.nav {
  position: sticky; top: 0; z-index: 20;
  backdrop-filter: blur(18px); -webkit-backdrop-filter: blur(18px);
  background: var(--nav-bg); border-bottom: 1px solid var(--line);
}

.nav-inner {
  min-height: 72px; display: flex; align-items: center;
  justify-content: space-between; gap: 20px;
}

.brand {
  display: flex; align-items: center; gap: 12px;
  font-weight: 900; font-size: 22px; letter-spacing: -.02em; white-space: nowrap;
}

.brand img { width: 44px; height: 44px; object-fit: contain; border-radius: 12px; }

.nav-links { display: flex; align-items: center; gap: 24px; color: var(--muted); font-size: 14px; }
.nav-links a:hover { color: var(--orange); }

.nav-actions { display: flex; align-items: center; gap: 10px; white-space: nowrap; }

.lang-dropdown { position: relative; }

.lang-btn {
  display: flex; align-items: center; gap: 6px; border: 0; border-radius: 10px;
  padding: 7px 9px; font-size: 14px; font-weight: 700;
  color: #4b5563; background: transparent; cursor: pointer;
  transition: background .16s ease, color .16s ease;
}

.lang-btn:hover { background: rgba(17,24,39,.06); color: #374151; }
.lang-flag { font-size: 16px; line-height: 1; }
.lang-code { font-size: 13px; }
.chevron { width: 12px; height: 12px; color: #9ca3af; transition: transform .2s ease; }

.theme-btn {
  width: 40px; height: 40px; border: 0; border-radius: 10px; padding: 8px;
  color: #6b7280; background: transparent; display: inline-grid; place-items: center;
  cursor: pointer; transition: background .16s ease, color .16s ease;
}

.theme-btn:hover { background: rgba(17,24,39,.06); color: #374151; }
.theme-icon { width: 20px; height: 20px; }
.hidden { display: none !important; }

html[data-theme="dark"] .lang-btn { color: #d1d5db; }
html[data-theme="dark"] .lang-btn:hover { background: rgba(255,255,255,.08); color: #fff; }
html[data-theme="dark"] .theme-btn { color: #9ca3af; }
html[data-theme="dark"] .theme-btn:hover { background: rgba(255,255,255,.08); color: #fff; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 44px; padding: 0 18px; border-radius: 999px;
  font-weight: 800; border: 1px solid transparent; cursor: pointer;
  transition: transform .16s ease, box-shadow .16s ease, background .16s ease;
}

.btn:hover { transform: translateY(-1px); }

.btn-primary {
  background: linear-gradient(135deg, var(--orange), var(--orange2));
  color: #fff; box-shadow: 0 14px 32px rgba(255,107,18,.25);
}

.btn-secondary {
  background: rgba(255,255,255,.72); border-color: var(--line); color: var(--text);
}

html[data-theme="dark"] .btn-secondary { background: rgba(255,255,255,.08); }

.hero { padding: 86px 0 58px; overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: 1.04fr .96fr; gap: 42px; align-items: center; }

.badge {
  display: inline-flex; align-items: center; gap: 8px; padding: 8px 12px;
  border-radius: 999px; background: rgba(255,107,18,.1); color: #df4d00;
  font-weight: 800; font-size: 13px; border: 1px solid rgba(255,107,18,.16);
}

html[data-theme="dark"] .badge { color: #ffb56b; }

h1 { margin: 20px 0 16px; font-size: clamp(42px,6vw,76px); line-height: 1.02; letter-spacing: -.06em; }

.gradient-text {
  background: linear-gradient(120deg,#111827 5%,#ff6b12 46%,#0b8fff 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}

html[data-theme="dark"] .gradient-text {
  background: linear-gradient(120deg,#f8fafc 5%,#ff9c42 46%,#7cc6ff 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}

.lead { font-size: 20px; line-height: 1.8; color: var(--muted); margin: 0 0 28px; max-width: 660px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 30px; }

.stats { display: grid; grid-template-columns: repeat(3,1fr); gap: 12px; max-width: 650px; }

.stat { padding: 16px; background: var(--soft); border: 1px solid var(--line); border-radius: 18px; }
.stat b { display: block; font-size: 22px; margin-bottom: 4px; }
.stat span { color: var(--muted); font-size: 13px; }

.visual { min-height: 480px; position: relative; display: grid; place-items: center; }

.visual::before {
  content: ""; position: absolute; width: min(420px,82vw); height: min(420px,82vw);
  border-radius: 50%; background:
    radial-gradient(circle at 50% 42%, rgba(255,210,30,.28), transparent 58%),
    radial-gradient(circle at 70% 28%, rgba(30,150,255,.16), transparent 48%);
  z-index: 0; pointer-events: none;
}

.hero-card {
  width: min(460px,88vw); padding: 34px; border-radius: 40px;
  background: rgba(255,255,255,.78); border: 1px solid rgba(255,255,255,.7);
  box-shadow: var(--shadow); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  text-align: center; position: relative; z-index: 1;
}

html[data-theme="dark"] .hero-card { background: rgba(24,32,48,.72); border-color: rgba(255,255,255,.12); }

.hero-logo {
  width: min(320px,82vw); height: auto; max-height: 250px; object-fit: contain;
  margin: 0 auto 18px; display: block; filter: drop-shadow(0 24px 34px rgba(255,184,0,.32));
}

.mini-panel { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 22px; text-align: left; }
.mini-panel div { padding: 14px; border-radius: 18px; background: var(--soft2); border: 1px solid var(--line); }
.mini-panel b { display:block; margin-bottom: 4px; }
.mini-panel span { color: var(--muted); font-size: 13px; }

section { padding: 68px 0; }
.section-head { text-align: center; margin-bottom: 34px; }

.eyebrow {
  display: inline-block; color: var(--orange); font-weight: 900; letter-spacing: .08em;
  font-size: 13px; text-transform: uppercase; margin-bottom: 10px;
}

h2 { margin: 0; font-size: clamp(30px,4vw,46px); line-height: 1.15; letter-spacing: -.04em; }

.section-desc { color: var(--muted); font-size: 17px; line-height: 1.75; margin: 14px auto 0; max-width: 760px; }

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

.feature {
  padding: 24px; border-radius: 24px; background: var(--card);
  border: 1px solid rgba(255,255,255,.8); box-shadow: 0 18px 44px rgba(18,38,63,.08);
}

html[data-theme="dark"] .feature,
html[data-theme="dark"] .step,
html[data-theme="dark"] .qa {
  border-color: rgba(255,255,255,.1); box-shadow: 0 18px 44px rgba(0,0,0,.18);
}

.feature .icon {
  width: 42px; height: 42px; border-radius: 14px; display: grid; place-items: center;
  background: rgba(255,107,18,.12); color: var(--orange); font-size: 22px; margin-bottom: 14px;
}

.feature h3, .price-card h3 { margin: 0 0 8px; font-size: 19px; }
.feature p { margin: 0; color: var(--muted); line-height: 1.7; font-size: 14px; }

.pricing { display: grid; grid-template-columns: repeat(3,1fr); gap: 22px; align-items: stretch; }

.price-card {
  position: relative; padding: 28px; border-radius: var(--radius);
  background: rgba(255,255,255,.9); border: 1px solid rgba(255,107,18,.22);
  box-shadow: var(--shadow); overflow: hidden;
}

html[data-theme="dark"] .price-card { background: rgba(24,32,48,.88); }

.price-card::before {
  content: ""; position: absolute; left: 0; right: 0; top: 0; height: 6px;
  background: linear-gradient(90deg,var(--orange),var(--orange2));
}

.price-card.highlight { transform: scale(1.035); border-color: rgba(255,107,18,.42); }

.tag {
  display: inline-flex; padding: 5px 9px; border-radius: 999px;
  background: rgba(255,107,18,.1); color: #ff5b00; font-size: 12px; font-weight: 800;
  margin-left: 8px; vertical-align: middle;
}

html[data-theme="dark"] .tag { color: #ffb56b; }

.price { display: flex; align-items: flex-end; gap: 8px; margin: 18px 0; }
.price small { color: var(--muted); transform: translateY(-8px); }
.price strong { font-size: 44px; line-height: 1; color: #f05a12; letter-spacing: -.04em; }
.price span { color: var(--muted); padding-bottom: 5px; }

.old-price { color: #98a2b3; text-decoration: line-through; font-size: 13px; margin-bottom: 18px; }

.quota {
  display: grid; grid-template-columns: 1fr 1fr; gap: 8px; background: var(--soft2);
  padding: 16px; border-radius: 18px; margin: 18px 0; color: var(--muted); font-size: 14px;
}

.quota b { color: var(--text); float: right; }

.list { list-style: none; padding: 0; margin: 18px 0 24px; }
.list li { display: flex; gap: 10px; margin: 12px 0; line-height: 1.65; color: var(--muted); font-size: 14px; }
.list li::before { content: "✓"; color: var(--orange); font-weight: 900; flex: 0 0 auto; }

.price-card .btn { width: 100%; border-radius: 14px; }

.metered {
  background: var(--dark-card); color: #fff; border-radius: 34px; padding: 34px;
  box-shadow: var(--shadow); overflow: hidden; position: relative;
}

.metered::after {
  content: ""; position: absolute; right: -120px; top: -120px; width: 340px; height: 340px;
  border-radius: 50%; background: radial-gradient(circle, rgba(255,210,30,.22), transparent 62%);
}

.metered-head {
  display: flex; justify-content: space-between; gap: 24px; align-items: flex-end;
  margin-bottom: 24px; position: relative; z-index: 1;
}

.metered h2 { color: #fff; }
.metered .section-desc { color: rgba(255,255,255,.68); margin-left: 0; }

.rate-table { width: 100%; border-collapse: collapse; position: relative; z-index: 1; overflow: hidden; border-radius: 18px; }

.rate-table th,
.rate-table td { padding: 18px 16px; text-align: left; border-bottom: 1px solid rgba(255,255,255,.1); }

.rate-table th { color: rgba(255,255,255,.68); font-size: 13px; font-weight: 800; }
.rate-table td { font-size: 18px; font-weight: 800; }
.rate-table td small { display: block; color: rgba(255,255,255,.56); font-size: 12px; margin-top: 4px; font-weight: 600; }

.model-opus48 { color: #d6b7ff; }
.model-sonnet { color: #9dccff; }
.model-opus46 { color: #ffca7a; }
.model-haiku { color: #86efac; }

.steps { display: grid; grid-template-columns: repeat(3,1fr); gap: 18px; }

.step, .qa {
  padding: 26px; border-radius: 24px; background: var(--card);
  border: 1px solid rgba(255,255,255,.8); box-shadow: 0 18px 44px rgba(18,38,63,.08);
}

.step-num {
  width: 38px; height: 38px; border-radius: 13px; background: #111827; color: #fff;
  display: grid; place-items: center; font-weight: 900; margin-bottom: 14px;
}

html[data-theme="dark"] .step-num { background: rgba(255,255,255,.12); }

.step h3, .qa h3 { margin: 0 0 8px; }
.step p, .qa p { margin: 0; color: var(--muted); line-height: 1.75; }

.faq { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }

.cta {
  padding: 54px; border-radius: 38px;
  background:
    radial-gradient(circle at 14% 20%, rgba(255,210,30,.45), transparent 34%),
    linear-gradient(135deg,#fff 0%,#fff1dc 100%);
  border: 1px solid rgba(255,255,255,.8); box-shadow: var(--shadow); text-align: center;
}

html[data-theme="dark"] .cta {
  background:
    radial-gradient(circle at 14% 20%, rgba(255,210,30,.18), transparent 34%),
    linear-gradient(135deg, rgba(24,32,48,.95) 0%, rgba(17,24,39,.95) 100%);
  border-color: rgba(255,255,255,.1);
}

.cta h2 { margin-bottom: 14px; }
.cta p { margin: 0 auto 24px; color: var(--muted); line-height: 1.75; max-width: 720px; }

footer { padding: 34px 0 46px; color: var(--muted); font-size: 14px; text-align: center; }

.note {
  margin-top: 16px; padding: 14px 16px; border-radius: 16px;
  background: rgba(255,107,18,.08); color: #9a3412; font-size: 13px; line-height: 1.65;
}

html[data-theme="dark"] .note { color: #ffbd8a; }

.lang-en { display: none; }
html[data-lang="en"] .lang-zh { display: none; }
html[data-lang="en"] .lang-en { display: inline; }

@media (max-width: 920px) {
  .nav-links { display: none; }
  .hero-grid { grid-template-columns: 1fr; }
  .visual { min-height: 360px; }
  .features, .pricing, .steps { grid-template-columns: 1fr; }
  .price-card.highlight { transform: none; }
  .faq { grid-template-columns: 1fr; }
  .metered-head { display: block; }
  .rate-table th:nth-child(4), .rate-table td:nth-child(4) { display: none; }
}

@media (max-width: 560px) {
  .container { width: min(100% - 24px,1180px); }
  .hero { padding-top: 52px; }
  .stats { grid-template-columns: 1fr; }
  .hero-card { padding: 24px; border-radius: 30px; }
  .hero-logo { width: min(280px,82vw); max-height: 220px; }
  .metered { padding: 22px; border-radius: 26px; }
  .rate-table th, .rate-table td { padding: 14px 10px; }
  .rate-table td { font-size: 15px; }
  .cta { padding: 32px 20px; }
  .brand span { font-size: 19px; }
  .lang-code { display: none; }
  .theme-btn { width: 38px; height: 38px; }
  .btn { padding: 0 14px; }
}