/* ============ 牙夜静 官网样式 ============ */
:root {
  --bg: #f5f7fb;
  --bg-dark: #05070f;
  --bg-deep: #0a0f1f;
  --card: #ffffff;
  --ink: #101322;
  --ink-2: #5a6072;
  --ink-3: #8a90a3;
  --primary: #2563eb;
  --primary-2: #7c3aed;
  --accent: #22d3ee;
  --grad: linear-gradient(120deg, #2563eb 0%, #7c3aed 100%);
  --grad-soft: linear-gradient(120deg, rgba(37,99,235,.12), rgba(124,58,237,.12));
  --radius: 18px;
  --shadow: 0 18px 50px -20px rgba(20,30,70,.25);
  --shadow-sm: 0 8px 24px -12px rgba(20,30,70,.18);
  --font: "Segoe UI", "PingFang SC", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, sans-serif;
  --maxw: 1180px;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
.wrap { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- 导航 ---------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(255,255,255,.82);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid rgba(15,23,42,.06);
  transition: box-shadow .3s ease;
}
.nav.scrolled { box-shadow: 0 10px 30px -18px rgba(20,30,70,.35); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 66px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 20px; letter-spacing: .5px; }
.brand .logo {
  width: 34px; height: 34px;
  object-fit: contain; display: block;
}
.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-links a {
  padding: 8px 14px; border-radius: 10px; font-size: 15px; color: var(--ink-2);
  transition: all .18s ease; white-space: nowrap;
}
.nav-links a:hover { color: var(--primary); background: rgba(37,99,235,.08); }
.nav-cta {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 18px; border-radius: 12px; color: #fff; background: var(--grad);
  font-weight: 600; font-size: 14px; box-shadow: 0 10px 24px -10px rgba(37,99,235,.8);
  transition: transform .18s ease, box-shadow .18s ease;
}
.nav-cta:hover { transform: translateY(-2px); box-shadow: 0 16px 30px -12px rgba(124,58,237,.9); }
.burger { display: none; flex-direction: column; gap: 5px; background: none; border: 0; cursor: pointer; padding: 8px; }
.burger span { width: 22px; height: 2px; background: var(--ink); border-radius: 2px; transition: .25s; }
.burger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.burger.open span:nth-child(2) { opacity: 0; }
.burger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- Hero ---------- */
.hero {
  position: relative; padding: 150px 0 90px;
  background: radial-gradient(1200px 600px at 85% -10%, rgba(124,58,237,.35), transparent 60%),
              radial-gradient(900px 500px at -10% 20%, rgba(34,211,238,.22), transparent 55%),
              linear-gradient(160deg, #05070f 0%, #0a0f1f 55%, #101832 100%);
  color: #eef2ff; overflow: hidden;
}
.hero::after {
  content: ""; position: absolute; inset: 0; pointer-events: none; opacity: .35;
  background-image: linear-gradient(rgba(255,255,255,.04) 1px, transparent 1px),
                    linear-gradient(90deg, rgba(255,255,255,.04) 1px, transparent 1px);
  background-size: 46px 46px;
  mask-image: radial-gradient(circle at 50% 40%, #000, transparent 75%);
}
.hero-grid { position: relative; z-index: 2; display: grid; grid-template-columns: 1.05fr .95fr; gap: 56px; align-items: center; }
.hero .eyebrow {
  display: inline-flex; align-items: center; gap: 8px; font-size: 13px; letter-spacing: 2px;
  color: var(--accent); text-transform: uppercase; margin-bottom: 22px;
}
.hero .eyebrow::before { content: ""; width: 26px; height: 2px; background: var(--accent); border-radius: 2px; }
.hero h1 { font-size: clamp(34px, 5vw, 58px); line-height: 1.15; font-weight: 800; letter-spacing: .5px; }
.hero h1 .grad { background: linear-gradient(120deg, #60a5fa, #a78bfa, #22d3ee); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero .sub { margin-top: 22px; font-size: 18px; color: #b7c1de; max-width: 520px; }
.hero .note { margin-top: 18px; font-size: 13.5px; color: #8d97b8; display: flex; gap: 8px; align-items: flex-start; }
.hero .note::before { content: "i"; flex: none; width: 18px; height: 18px; border-radius: 50%; background: rgba(34,211,238,.2); color: var(--accent); display: grid; place-items: center; font-size: 11px; font-weight: 700; margin-top: 3px; }
.hero-actions { display: flex; gap: 14px; margin-top: 32px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 9px; padding: 14px 26px; border-radius: 13px;
  font-weight: 600; font-size: 15px; cursor: pointer; border: 0; transition: all .2s ease;
}
.btn-primary { background: var(--grad); color: #fff; box-shadow: 0 14px 30px -12px rgba(99,102,241,.9); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 20px 40px -14px rgba(124,58,237,.95); }
.btn-ghost { background: rgba(255,255,255,.08); color: #e6eaff; border: 1px solid rgba(255,255,255,.18); }
.btn-ghost:hover { background: rgba(255,255,255,.16); }
.hero-visual { position: relative; }
.hero-visual .frame {
  border-radius: 20px; overflow: hidden; border: 1px solid rgba(255,255,255,.12);
  box-shadow: 0 40px 80px -30px rgba(0,0,0,.7); background: #0c1326;
}
.hero-visual img { width: 100%; object-fit: cover; }
.float-chip {
  position: absolute; background: rgba(16,22,44,.85); backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,.14); border-radius: 13px; padding: 10px 14px;
  font-size: 13px; color: #cfe0ff; box-shadow: 0 18px 40px -18px rgba(0,0,0,.8);
  display: flex; align-items: center; gap: 9px; animation: float 5s ease-in-out infinite;
}
.float-chip .dot { width: 9px; height: 9px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 0 4px rgba(34,211,238,.2); }
.chip-a { top: 18px; left: -18px; }
.chip-b { bottom: 22px; right: -14px; animation-delay: -2.5s; }
@keyframes float { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-10px); } }

/* ---------- 区块通用 ---------- */
.section { padding: 96px 0; }
.section.dark { background: var(--bg-dark); color: #eef2ff; }
.sec-head { max-width: 640px; margin: 0 auto 56px; text-align: center; }
.sec-head .tag { display: inline-block; font-size: 13px; letter-spacing: 2px; color: var(--primary); font-weight: 700; text-transform: uppercase; margin-bottom: 14px; }
.section.dark .sec-head .tag { color: var(--accent); }
.sec-head h2 { font-size: clamp(26px, 3.4vw, 38px); font-weight: 800; line-height: 1.25; }
.sec-head p { margin-top: 14px; color: var(--ink-2); font-size: 16.5px; }
.section.dark .sec-head p { color: #aab3d0; }

/* ---------- 卖点卡片 ---------- */
.features { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.fcard {
  background: var(--card); border-radius: var(--radius); padding: 30px 26px;
  box-shadow: var(--shadow-sm); border: 1px solid rgba(15,23,42,.05);
  transition: transform .25s ease, box-shadow .25s ease;
}
.fcard:hover { transform: translateY(-6px); box-shadow: var(--shadow); }
.fcard .ico { width: 50px; height: 50px; border-radius: 14px; display: grid; place-items: center; font-size: 24px; background: var(--grad-soft); margin-bottom: 18px; }
.fcard h3 { font-size: 18px; font-weight: 700; margin-bottom: 9px; }
.fcard p { font-size: 14.5px; color: var(--ink-2); }

/* ---------- 产品说明 (ya1/ya2) ---------- */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center; }
.split .copy h2 { font-size: clamp(26px, 3.4vw, 36px); font-weight: 800; line-height: 1.3; }
.split .copy p { margin-top: 16px; color: var(--ink-2); font-size: 16px; }
.split .copy ul { margin-top: 20px; list-style: none; }
.split .copy ul li { padding: 6px 0 6px 30px; position: relative; color: var(--ink-2); font-size: 15.5px; }
.split .copy ul li::before { content: "✓"; position: absolute; left: 0; top: 6px; width: 20px; height: 20px; border-radius: 50%; background: var(--grad); color: #fff; display: grid; place-items: center; font-size: 12px; font-weight: 700; }
.split .media { display: grid; gap: 20px; }
.split .media .shot { border-radius: 16px; overflow: hidden; border: 1px solid rgba(15,23,42,.08); box-shadow: var(--shadow-sm); }
.split .media .shot img { width: 100%; }
.split.rev { direction: rtl; }
.split.rev > * { direction: ltr; }

/* ---------- 使用建议 ---------- */
.tips-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.tip {
  background: rgba(255,255,255,.05); border: 1px solid rgba(255,255,255,.1);
  border-radius: var(--radius); padding: 30px 26px; transition: transform .25s ease;
}
.tip:hover { transform: translateY(-5px); }
.tip .num { font-size: 30px; font-weight: 800; background: linear-gradient(120deg,#60a5fa,#a78bfa); -webkit-background-clip: text; background-clip: text; color: transparent; margin-bottom: 10px; }
.tip h3 { font-size: 17px; margin-bottom: 8px; }
.tip p { font-size: 14.5px; color: #aab3d0; }

/* ---------- 上传分析 CTA ---------- */
.upload-box {
  background: var(--card); border-radius: 24px; padding: 54px; text-align: center;
  box-shadow: var(--shadow); border: 1px solid rgba(15,23,42,.06);
  max-width: 720px; margin: 0 auto; position: relative; overflow: hidden;
}
.upload-box::before { content: ""; position: absolute; inset: 0; background: radial-gradient(500px 200px at 50% 0%, rgba(124,58,237,.12), transparent 70%); pointer-events: none; }
.dropzone {
  position: relative; margin: 30px auto 20px; max-width: 520px; padding: 44px 30px;
  border: 2px dashed rgba(37,99,235,.4); border-radius: 18px; background: rgba(37,99,235,.04);
  transition: .2s ease; cursor: pointer;
}
.dropzone:hover, .dropzone.drag { border-color: var(--primary); background: rgba(37,99,235,.08); }
.dropzone .ico { font-size: 40px; margin-bottom: 12px; }
.dropzone p { color: var(--ink-2); font-size: 15px; }
.dropzone .hint { margin-top: 8px; font-size: 12.5px; color: var(--ink-3); }
.upload-status { min-height: 22px; font-size: 14px; color: var(--ink-2); margin-top: 6px; }
.upload-status.ok { color: #16a34a; }
.upload-status.err { color: #dc2626; }
.badge-soon { display: inline-block; font-size: 12px; letter-spacing: 1px; color: var(--primary); background: rgba(37,99,235,.1); padding: 4px 12px; border-radius: 99px; font-weight: 700; margin-bottom: 16px; }

/* ---------- 页脚 ---------- */
.footer { background: #04060c; color: #8d97b8; padding: 64px 0 40px; }
.footer .grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 40px; }
.footer .brand { color: #fff; margin-bottom: 14px; }
.footer p { font-size: 14px; }
.footer h4 { color: #e6eaff; font-size: 14px; letter-spacing: 1px; margin-bottom: 16px; }
.footer ul { list-style: none; }
.footer ul li { margin-bottom: 10px; }
.footer ul li a { font-size: 14px; transition: color .15s; }
.footer ul li a:hover { color: #fff; }
.footer .bottom { margin-top: 48px; padding-top: 24px; border-top: 1px solid rgba(255,255,255,.08); display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; font-size: 13px; }

/* ---------- 协议/政策页 ---------- */
.legal { padding: 140px 0 90px; }
.legal-card { background: var(--card); border-radius: 22px; box-shadow: var(--shadow-sm); border: 1px solid rgba(15,23,42,.06); padding: 56px; max-width: 840px; margin: 0 auto; }
.legal-card h1 { font-size: 30px; font-weight: 800; margin-bottom: 6px; }
.legal-card .update { color: var(--ink-3); font-size: 13px; margin-bottom: 32px; }
.legal-card h2 { font-size: 20px; font-weight: 700; margin: 34px 0 12px; padding-top: 8px; }
.legal-card h3 { font-size: 16px; font-weight: 700; margin: 22px 0 8px; }
.legal-card p, .legal-card li { font-size: 15px; color: #33384d; }
.legal-card ul { padding-left: 20px; }
.legal-card li { margin-bottom: 8px; }
.legal-card a { color: var(--primary); }

/* ---------- 响应式 ---------- */
@media (max-width: 960px) {
  .features { grid-template-columns: repeat(2, 1fr); }
  .tips-grid { grid-template-columns: 1fr; }
  .split { grid-template-columns: 1fr; gap: 34px; }
  .split.rev { direction: ltr; }
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .chip-a { left: 6px; } .chip-b { right: 6px; }
  .footer .grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 680px) {
  .nav-links { position: fixed; top: 66px; left: 0; right: 0; background: #fff; flex-direction: column; align-items: stretch; padding: 12px 16px 18px; gap: 4px; border-bottom: 1px solid rgba(15,23,42,.06); box-shadow: 0 20px 40px -20px rgba(0,0,0,.3); transform: translateY(-120%); transition: transform .3s ease; }
  .nav-links.open { transform: translateY(0); }
  .nav-links a { padding: 12px 14px; }
  .burger { display: flex; }
  .nav-cta { display: none; }
  .features { grid-template-columns: 1fr; }
  .hero { padding: 120px 0 64px; }
  .legal-card { padding: 34px 22px; }
  .upload-box { padding: 36px 20px; }
  .footer .grid { grid-template-columns: 1fr; }
}

/* ---------- 磨耗对比 ---------- */
.compare-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; margin-top: 24px; }
.compare-card { border-radius: 16px; padding: 24px 22px; border: 1px solid; }
.compare-card.normal { background: rgba(34,197,94,.07); border-color: rgba(34,197,94,.3); }
.compare-card.bad { background: rgba(239,68,68,.07); border-color: rgba(239,68,68,.3); }
.compare-card .label { font-size: 13.5px; font-weight: 700; letter-spacing: .5px; }
.compare-card.normal .label { color: #16a34a; }
.compare-card.bad .label { color: #dc2626; }
.compare-card .value { font-size: 32px; font-weight: 800; margin: 10px 0 2px; line-height: 1.1; }
.compare-card .unit { font-size: 13px; color: var(--ink-3); }
.compare-card .sub { margin-top: 10px; font-size: 13px; color: var(--ink-2); }
.compare-note { margin-top: 20px; font-size: 15px; color: var(--ink-2); }
.compare-note strong { color: #dc2626; font-size: 17px; }
@media (max-width: 960px) {
  .compare-grid { grid-template-columns: 1fr; }
}

/* ---------- 上传分析 ---------- */
.mode-row { display: flex; justify-content: center; gap: 12px; margin-top: 20px; flex-wrap: wrap; }
.mode-opt { display: inline-flex; align-items: center; gap: 6px; padding: 9px 16px; border-radius: 99px; border: 1px solid rgba(15,23,42,.12); cursor: pointer; font-size: 14px; color: var(--ink-2); transition: .18s; background: #fff; font-family: inherit; }
.mode-opt.active { border-color: var(--primary); background: rgba(37,99,235,.08); color: var(--primary); font-weight: 600; }
.progress-wrap { max-width: 520px; margin: 22px auto 0; }
.progress-bar { height: 10px; border-radius: 99px; background: rgba(37,99,235,.12); overflow: hidden; }
.progress-fill { height: 100%; width: 0; background: var(--grad); border-radius: 99px; transition: width .3s ease; }
.progress-text { margin-top: 8px; font-size: 13px; color: var(--ink-2); text-align: center; }
.result { margin-top: 28px; text-align: left; }
.result-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.stat { background: linear-gradient(160deg, #f5f7ff, #fbf5ff); border: 1px solid rgba(15,23,42,.06); border-radius: 16px; padding: 22px 16px; text-align: center; }
.stat .num { font-size: 34px; font-weight: 800; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.stat .lbl { margin-top: 4px; font-size: 13px; color: var(--ink-2); }
.ep-list { margin-top: 20px; background: #fff; border: 1px solid rgba(15,23,42,.06); border-radius: 16px; padding: 20px; }
.ep-list h4 { font-size: 15px; margin-bottom: 10px; }
.ep-list ul { list-style: none; max-height: 220px; overflow: auto; }
.ep-list li { padding: 6px 0; border-bottom: 1px dashed rgba(15,23,42,.08); font-size: 14px; color: var(--ink-2); }
.ep-list .more { margin-top: 8px; font-size: 13px; color: var(--ink-3); }
.no-ep { margin-top: 16px; color: #16a34a; font-size: 15px; text-align: center; }
@media (max-width: 680px) {
  .result-grid { grid-template-columns: 1fr; }
}