:root {
  color-scheme: light;
  --bg: #f5f7fb;
  --bg-2: #edf1f7;
  --surface: #ffffff;
  --surface-2: #f9fbfd;
  --ink: #0f172a;
  --ink-2: #334155;
  --muted: #64748b;
  --line: #e2e8f0;
  --accent: #1668e3;
  --accent-hover: #0f56c4;
  --accent-soft: #e8f0fe;
  --ok: #0f8a4d;
  --ok-soft: #e6f5ec;
  --warn: #a15c00;
  --warn-soft: #fff4e0;
  --glow: rgba(22, 104, 227, .14);
  --skeleton: #d9e2ef;
  --shadow: 0 24px 64px -28px rgba(15, 23, 42, .25);
  --shadow-sm: 0 8px 28px -18px rgba(15, 23, 42, .18);
  --radius: 16px;
  --maxw: 1120px;
  --sans: -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0f1217;
  --bg-2: #151a22;
  --surface: #1b2027;
  --surface-2: #171c23;
  --ink: #e6e9ee;
  --ink-2: #c3cad4;
  --muted: #9aa3ae;
  --line: #2a3038;
  --accent: #4c8dff;
  --accent-hover: #6ba1ff;
  --accent-soft: #1c2a44;
  --ok: #5fd08a;
  --ok-soft: #1c3a29;
  --warn: #e0a95a;
  --warn-soft: #3a2f1c;
  --glow: rgba(76, 141, 255, .16);
  --skeleton: #333c4a;
  --shadow: 0 24px 64px -28px rgba(0, 0, 0, .55);
  --shadow-sm: 0 8px 28px -18px rgba(0, 0, 0, .5);
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  overflow-x: hidden;
  font-family: var(--sans);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.wrap { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 28px; }
section[id] { scroll-margin-top: 84px; }

/* ── 顶部导航 ── */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: var(--bg);
  border-bottom: 1px solid transparent;
}
.nav.scrolled { border-bottom-color: var(--line); box-shadow: var(--shadow-sm); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; gap: 16px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 16px; white-space: nowrap; }
.brand img { width: 30px; height: 30px; border-radius: 7px; }
.nav-links { display: flex; align-items: center; gap: 2px; flex-wrap: wrap; justify-content: flex-end; }
.nav-links a { padding: 7px 12px; font-size: 14px; color: var(--ink-2); border-radius: 999px; }
.nav-links a:hover { background: var(--accent-soft); color: var(--ink); }
.nav-links a.nav-dl { background: var(--accent); color: #fff; font-weight: 700; margin-left: 6px; }
.nav-links a.nav-dl:hover { background: var(--accent-hover); }
.nav-links a.nav-login { color: var(--accent); font-weight: 600; }
.nav-links a.nav-home { color: var(--muted); font-size: 13px; }
.theme-toggle {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 6px 12px; border-radius: 999px; border: 1px solid var(--line);
  background: var(--surface); color: var(--muted); cursor: pointer;
  font-size: 13px; line-height: 1.2; font-family: inherit; margin-left: 6px;
}
.theme-toggle:hover { color: var(--ink); border-color: var(--accent); }
.theme-toggle .theme-icon { font-size: 14px; line-height: 1; }

/* ── 首屏 ── */
.hero { position: relative; overflow: hidden; padding: 68px 0 56px; }
.hero::after {
  content: ""; position: absolute; inset: auto -10% -38% 42%; height: 70%;
  background: radial-gradient(50% 50% at 50% 50%, var(--glow), transparent 70%);
  pointer-events: none;
}
.hero-inner { position: relative; display: grid; grid-template-columns: 1.05fr .95fr; gap: 52px; align-items: center; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  border: 1px solid var(--line); background: var(--surface);
  padding: 5px 14px; border-radius: 999px; font-size: 13px; color: var(--ink-2);
}
.eyebrow img { width: 18px; height: 18px; border-radius: 4px; }
.hero h1 { font-size: clamp(32px, 4.4vw, 50px); line-height: 1.18; letter-spacing: -.02em; margin: 18px 0 14px; font-weight: 800; }
.hero h1 em { font-style: normal; color: var(--accent); }
.hero .sub { font-size: 16px; color: var(--muted); max-width: 500px; margin-bottom: 22px; }
.hero-cta { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 14px; margin-bottom: 14px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 22px; border-radius: 999px; font-size: 15px; font-weight: 700;
  border: 1px solid transparent; cursor: pointer; font-family: inherit;
}
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-hover); }
.btn-ghost { background: var(--surface); border-color: var(--line); color: var(--ink); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn-sm { padding: 8px 16px; font-size: 13.5px; }
.dl-note { font-size: 12.5px; color: var(--muted); margin-bottom: 18px; }
.checks { list-style: none; display: grid; gap: 9px; }
.checks li { display: flex; gap: 10px; font-size: 14.5px; color: var(--ink-2); }
.checks i {
  flex: 0 0 20px; height: 20px; border-radius: 50%; background: var(--accent);
  color: #fff; font-style: normal; font-size: 12px; font-weight: 700;
  display: grid; place-items: center; margin-top: 3px;
}

/* ── 首屏产品窗口 ── */
.hero-visual { position: relative; min-height: 330px; }
.win {
  background: var(--surface); border: 1px solid var(--line); border-radius: 14px;
  overflow: hidden; box-shadow: var(--shadow); transform: rotate(-1.1deg);
}
.win-bar {
  display: flex; align-items: center; gap: 6px; padding: 9px 12px;
  background: var(--bg-2); border-bottom: 1px solid var(--line);
  font-size: 12px; color: var(--muted);
}
.win-bar .d { width: 8px; height: 8px; border-radius: 50%; background: var(--line); }
.win-bar .win-title { margin-left: 8px; }
.win-body { background: var(--surface-2); }
.float-card {
  position: absolute; display: flex; flex-direction: column; gap: 2px;
  background: var(--surface); border: 1px solid var(--line); border-radius: 12px;
  padding: 10px 14px; box-shadow: var(--shadow-sm); font-size: 12px; color: var(--muted);
}
.float-card b { font-size: 15px; color: var(--ink); }
.float-card .mini { font-size: 11px; }
.fc-1 { left: -18px; bottom: 26px; transform: rotate(-2deg); }
.fc-2 { right: -12px; top: 26px; transform: rotate(2deg); }
.fc-2 .ok { color: var(--ok); font-weight: 700; }

/* ── 截图与占位 ── */
.shot-img { width: 100%; height: auto; display: block; }
.shot-ph {
  position: relative; aspect-ratio: 16 / 10; overflow: hidden;
  background: linear-gradient(135deg, var(--surface-2), var(--bg-2));
  display: flex; align-items: center; justify-content: center;
}
.ph-ui { position: absolute; inset: 0; display: grid; grid-template-columns: 17% 27% 1fr; opacity: .85; }
.ph-side { background: var(--surface); border-right: 1px solid var(--line); }
.ph-list { padding: 14px 10px; display: flex; flex-direction: column; gap: 10px; border-right: 1px solid var(--line); }
.ph-list i { display: block; height: 24px; border-radius: 7px; background: var(--skeleton); }
.ph-list i:nth-child(2n) { width: 78%; }
.ph-chat { padding: 18px 16px; display: flex; flex-direction: column; gap: 11px; }
.ph-b { height: 30px; border-radius: 9px; background: var(--skeleton); }
.ph-b.l { width: 62%; }
.ph-b.r { width: 50%; align-self: flex-end; background: var(--accent-soft); }
.ph-b.l2 { width: 46%; }
.ph-b.r2 { width: 66%; }
.ph-tag {
  position: relative; z-index: 1; display: flex; flex-direction: column; align-items: center; gap: 4px;
  background: var(--surface); border: 1px solid var(--line); border-radius: 12px;
  padding: 12px 18px; box-shadow: var(--shadow-sm); text-align: center; color: var(--muted);
}
.ph-tag .ph-glyph { font-size: 22px; color: var(--accent); line-height: 1; }
.ph-tag .ph-title { font-size: 13px; font-weight: 600; color: var(--ink-2); }
.ph-tag code { font-size: 11px; color: var(--muted); }

/* ── 规格条 ── */
.spec { margin: 0 auto 68px; max-width: var(--maxw); padding: 0 28px; }
.spec-card {
  background: var(--surface); border: 1px solid var(--line); border-radius: 20px;
  padding: 20px 24px 6px; box-shadow: var(--shadow-sm);
}
.spec-top { display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; margin-bottom: 16px; }
.spec-brand { display: flex; align-items: center; gap: 12px; }
.spec-brand img { width: 38px; height: 38px; border-radius: 9px; }
.spec-brand strong { display: block; font-size: 15px; }
.spec-brand span { font-size: 12.5px; color: var(--muted); }
.tag { font-size: 12px; padding: 4px 10px; border-radius: 999px; background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.spec-grid { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); }
.spec-grid div { padding: 14px 8px 16px; text-align: center; }
.spec-grid b { display: block; font-size: 14px; }
.spec-grid span { font-size: 12px; color: var(--muted); }

/* ── 通用区块 ── */
.section { padding: 76px 0; }
.section.alt { background: var(--bg-2); }
.sec-head { text-align: center; margin-bottom: 40px; }
.kicker { font-size: 13px; color: var(--accent); font-weight: 700; letter-spacing: .08em; margin-bottom: 8px; }
.sec-head h2 { font-size: clamp(24px, 3vw, 34px); font-weight: 800; letter-spacing: -.02em; }
.sec-head p { color: var(--muted); margin-top: 8px; }

/* ── 功能卡片 ── */
.cards { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 20px; transition: transform .18s ease, box-shadow .18s ease;
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-sm); }
.card .ico {
  width: 42px; height: 42px; border-radius: 12px; display: grid; place-items: center;
  background: var(--accent-soft); color: var(--accent); font-size: 19px; margin-bottom: 12px;
}
.card .n { font-size: 12px; color: var(--accent); font-weight: 700; }
.card h3 { font-size: 16px; margin: 4px 0 6px; }
.card p { font-size: 13.5px; color: var(--muted); }

/* ── 左右交替介绍 ── */
.zig { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; margin-bottom: 56px; }
.zig:last-child { margin-bottom: 0; }
.zig[id] { scroll-margin-top: 84px; }
.zig.reverse .copy { order: 2; }
.zig .frame {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; box-shadow: var(--shadow);
}
.zig h3 { font-size: 24px; font-weight: 800; margin-bottom: 12px; letter-spacing: -.01em; }
.zig p { color: var(--muted); font-size: 15px; margin-bottom: 12px; }
.zig ul { padding-left: 18px; color: var(--ink-2); font-size: 15px; }
.zig li { margin: 6px 0; }
.badge { display: inline-block; font-size: 11px; font-weight: 700; color: var(--accent); background: var(--accent-soft); padding: 2px 8px; border-radius: 999px; vertical-align: 2px; margin-left: 6px; }

/* ── AI 问答示例卡片 ── */
.qa-demo {
  margin-top: 18px; padding: 16px; display: grid; gap: 12px;
  background: var(--surface); border: 1px solid var(--line);
  border-radius: 14px; box-shadow: var(--shadow-sm);
}
.qa-q, .qa-a { display: flex; gap: 10px; align-items: flex-start; }
.qa-a { border-top: 1px dashed var(--line); padding-top: 12px; }
.qa-avatar {
  flex: 0 0 28px; width: 28px; height: 28px; border-radius: 50%;
  background: var(--bg-2); color: var(--muted);
  display: grid; place-items: center; font-size: 11px; font-weight: 700;
}
.qa-a .qa-avatar { background: var(--accent-soft); color: var(--accent); }
.qa-demo p { margin: 0; color: var(--ink-2); font-size: 13.5px; line-height: 1.75; }
.qa-src { margin-top: 6px; font-size: 12px; color: var(--accent); }
/* ── 三步骤 ── */
.steps { display: grid; grid-template-columns: 1fr auto 1fr auto 1fr; gap: 10px; align-items: start; }
.step { text-align: center; padding: 8px 10px; }
.step .ico {
  width: 52px; height: 52px; margin: 0 auto 12px; border-radius: 14px;
  border: 1px solid var(--line); background: var(--surface);
  display: grid; place-items: center; font-size: 20px; color: var(--accent);
}
.step .no { font-size: 12px; color: var(--accent); font-weight: 700; }
.step h3 { font-size: 16px; margin: 4px 0 6px; }
.step p { font-size: 13px; color: var(--muted); }
.arrow { color: var(--muted); opacity: .5; font-size: 22px; padding-top: 24px; text-align: center; }

/* ── 对比 ── */
.compare { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.cmp { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; }
.cmp.good { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent-soft); }
.cmp h3 { margin-bottom: 12px; font-size: 18px; }
.cmp.good h3 { color: var(--accent); }
.cmp li { margin: 8px 0 8px 18px; color: var(--ink-2); font-size: 14.5px; }

/* ── 截图画廊 ── */
.gallery { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.gallery-item {
  display: block; border-radius: 12px; overflow: hidden; border: 1px solid var(--line);
  background: var(--surface); aspect-ratio: 1.9 / 1; position: relative;
}
.gallery-item img { width: 100%; height: 100%; object-fit: cover; object-position: top center; }
.gallery-item:hover { outline: 2px solid var(--accent); outline-offset: 1px; }
.gallery-item.is-ph { display: grid; place-items: center; background: linear-gradient(135deg, var(--surface-2), var(--bg-2)); }
.gallery-item.is-ph span { position: relative; z-index: 1; font-size: 13px; color: var(--muted); background: var(--surface); border: 1px solid var(--line); padding: 8px 14px; border-radius: 999px; }
.gallery-cap { position: absolute; left: 10px; bottom: 10px; font-size: 12px; color: #fff; background: rgba(15, 23, 42, .62); padding: 3px 9px; border-radius: 999px; }

/* ── 价格 ── */
.price-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 16px; margin-bottom: 28px; }
.price-card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 24px; display: flex; flex-direction: column; gap: 12px;
}
.price-card.featured { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent-soft); }
.price-card .plan-name { color: var(--muted); font-size: 13.5px; }
.price-card .plan-price { font-size: 30px; font-weight: 800; letter-spacing: -.02em; }
.price-card .plan-price span { font-size: 13px; font-weight: 400; color: var(--muted); }
.price-card .plan-term { color: var(--muted); font-size: 12.5px; }
.price-card ul { list-style: none; display: grid; gap: 7px; margin: 2px 0 6px; }
.price-card li { font-size: 13.5px; color: var(--ink-2); padding-left: 20px; position: relative; }
.price-card li::before { content: "✓"; position: absolute; left: 0; color: var(--ok); font-weight: 700; }
.price-card .btn { width: 100%; }
.price-note { color: var(--muted); font-size: 13px; text-align: center; }

/* ── 功能对照表 ── */
.table-wrap { overflow-x: auto; margin-top: 28px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); }
table { width: 100%; border-collapse: collapse; font-size: 14px; min-width: 560px; }
th, td { text-align: left; padding: 12px 16px; border-bottom: 1px solid var(--line); }
th { color: var(--muted); font-size: 12px; font-weight: 600; }
tr:last-child td { border-bottom: none; }
td.yes { color: var(--ok); }
td.no { color: var(--muted); }

/* ── FAQ ── */
.faq { max-width: 820px; margin: 0 auto; display: grid; gap: 10px; }
.faq details { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 0 18px; }
.faq summary { cursor: pointer; padding: 15px 0; font-weight: 600; font-size: 15px; list-style: none; display: flex; justify-content: space-between; gap: 12px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--muted); font-weight: 400; }
.faq details[open] summary::after { content: "−"; }
.faq .answer { padding: 0 0 15px; color: var(--muted); font-size: 14px; }

/* ── 底部 CTA ── */
.cta-band {
  text-align: center; background: var(--surface); border: 1px solid var(--line);
  border-radius: 20px; padding: 38px 24px; box-shadow: var(--shadow-sm);
}
.cta-band h2 { font-size: 26px; font-weight: 800; margin: 0 0 8px; }
.cta-band p { color: var(--muted); margin-bottom: 18px; }
.cta-band .hero-cta { justify-content: center; margin-bottom: 0; }

/* ── 使用案例（WorkBuddy） ── */
.case {
  display: grid; grid-template-columns: 1.05fr .95fr; gap: 28px;
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px; box-shadow: var(--shadow-sm); margin-top: 8px;
}
.case[id] { scroll-margin-top: 84px; }
.case h3 { font-size: 22px; font-weight: 800; letter-spacing: -.01em; margin: 4px 0 10px; }
.case p { color: var(--muted); font-size: 14.5px; }
.case-steps { list-style: none; counter-reset: case-step; display: grid; gap: 12px; margin-top: 16px; }
.case-steps li { counter-increment: case-step; position: relative; padding-left: 36px; }
.case-steps li::before {
  content: counter(case-step); position: absolute; left: 0; top: 2px;
  width: 24px; height: 24px; border-radius: 50%; background: var(--accent-soft);
  color: var(--accent); font-size: 12px; font-weight: 700; display: grid; place-items: center;
}
.case-steps b { display: block; font-size: 14.5px; }
.case-steps span { color: var(--muted); font-size: 13.5px; line-height: 1.7; }
.case-side { display: flex; flex-direction: column; }
.case-prompt-label { font-size: 12px; color: var(--muted); font-weight: 600; margin-bottom: 6px; }
.case-prompt {
  background: var(--code-bg); border: 1px solid var(--line); border-radius: 12px;
  padding: 16px; margin: 0; font-size: 13px; line-height: 1.75; color: var(--ink-2);
  white-space: pre-wrap; font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
}
.case-note { font-size: 12.5px; color: var(--muted); margin-top: 10px; line-height: 1.7; }
.case-shots { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 18px; }
.case-shot { margin: 0; }
.case-shot .frame {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; box-shadow: var(--shadow-sm);
}
.case-shot figcaption { text-align: center; font-size: 12.5px; color: var(--muted); margin-top: 8px; }
/* ── 页脚 ── */
footer { border-top: 1px solid var(--line); padding: 40px 0 24px; margin-top: 12px; }
.foot { display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
.foot .left { max-width: 460px; }
.foot .brand { margin-bottom: 10px; }
.foot p, .foot a { font-size: 13.5px; color: var(--muted); }
.foot-col { display: flex; flex-direction: column; gap: 8px; }
.foot-col h4 { font-size: 13px; color: var(--ink); margin-bottom: 4px; }
.foot-bottom { margin-top: 28px; padding-top: 16px; border-top: 1px solid var(--line); display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; font-size: 12.5px; color: var(--muted); }

/* ── 大图预览 ── */
.lb { position: fixed; inset: 0; background: rgba(15, 23, 42, .78); display: none; place-items: center; z-index: 80; padding: 24px; }
.lb.open { display: grid; }
.lb img { max-width: min(1200px, 94vw); max-height: 90vh; border-radius: 12px; box-shadow: var(--shadow); background: var(--surface); }

@media (max-width: 980px) {
  .hero-inner, .zig, .zig.reverse .copy, .cards, .compare, .price-grid { grid-template-columns: 1fr; }
  .zig.reverse .copy { order: 0; }
  .spec-grid { grid-template-columns: repeat(2, 1fr); }
  .gallery { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: 1fr; }
  .case { grid-template-columns: 1fr; }
  .case-shots { grid-template-columns: 1fr; }
  .arrow { display: none; }
  .hero { padding-top: 44px; }
  .hero-visual { min-height: 0; }
  .float-card { display: none; }
  .nav-links a:not(.nav-dl):not(.nav-login) { display: none; }
  .theme-toggle { margin-left: 0; }
}
@media (max-width: 640px) {
  .wrap { padding: 0 18px; }
  .nav-inner { gap: 8px; }
  .brand { font-size: 15px; gap: 8px; }
  .brand img { width: 26px; height: 26px; }
  .nav-links { gap: 0; }
  .nav-links a { padding: 7px 8px; }
  .nav-links a.nav-dl { padding: 7px 12px; }
  .theme-toggle { padding: 6px 8px; }
  .theme-toggle .theme-label { display: none; }
  .hero h1 { font-size: 31px; }
  .hero .sub { font-size: 15px; }
  .section { padding: 56px 0; }
  .spec { padding: 0 18px; margin-bottom: 52px; }
  .cards, .gallery { grid-template-columns: 1fr; }
  .case { padding: 20px; }
  .win { transform: none; }
  .foot { flex-direction: column; }
}