/* ============================================================
   DWZ ShortURL 项目宣传站 - 样式（v5 亮色重写）
   设计语言：Vercel Minimal（site/DESIGN.md）
   - 近白画布 #fafafa + 纯白卡片 #ffffff + 墨黑 ink #171717
   - 主 CTA：墨黑 100px pill；导航按钮：6px 方角
   - hero 顶部 mesh gradient（蓝/紫/粉低饱和）是唯一装饰
   - 卡片 8px 圆角 + stacked shadow + inset hairline
   - 深墨黑 #171717 极性翻转 band 作为产品面板与代码块
   ============================================================ */

:root {
  --canvas: #ffffff;
  --canvas-soft: #fafafa;
  --canvas-soft-2: #f5f5f5;
  --hairline: #ebebeb;
  --hairline-strong: #a1a1a1;

  --ink: #171717;
  --body: #4d4d4d;
  --mute: #888888;
  --on-primary: #ffffff;

  --link: #0070f3;
  --link-deep: #0761d1;
  --error: #ee0000;
  --warning: #f5a623;
  --success: #27a644;

  --grad-dev-1: #007cf0;
  --grad-dev-2: #00dfd8;
  --grad-prev-1: #7928ca;
  --grad-prev-2: #ff0080;
  --grad-ship-1: #ff4d4d;
  --grad-ship-2: #f9cb28;

  --font-sans: Inter, "SF Pro Display", -apple-system, BlinkMacSystemFont,
               "Segoe UI", "PingFang SC", "Hiragino Sans GB",
               "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "SF Mono", "Cascadia Code",
               Consolas, monospace;

  --r-xs: 4px;
  --r-sm: 6px;
  --r-md: 8px;
  --r-lg: 12px;
  --r-pill: 100px;
  --r-full: 9999px;

  --maxw: 1240px;
  --nav-h: 64px;

  --shadow-card:
    inset 0 0 0 1px rgba(0, 0, 0, 0.08),
    0px 1px 1px rgba(0, 0, 0, 0.05),
    0px 2px 2px rgba(0, 0, 0, 0.06);
  --shadow-lift:
    inset 0 0 0 1px rgba(0, 0, 0, 0.08),
    0px 2px 2px rgba(0, 0, 0, 0.06),
    0px 8px 16px -4px rgba(0, 0, 0, 0.06);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 12px); }

body {
  font-family: var(--font-sans);
  background: var(--canvas-soft);
  color: var(--ink);
  line-height: 1.5;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

::selection { background: rgba(0, 112, 243, 0.16); }

a { color: var(--link); text-decoration: none; }
a:hover { color: var(--link-deep); }

:focus-visible { outline: 2px solid rgba(0, 112, 243, 0.45); outline-offset: 2px; border-radius: var(--r-xs); }

.mono { font-family: var(--font-mono); }
.tnum { font-variant-numeric: tabular-nums; }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ================= 导航（Vercel nav-bar：64px / 白底 / 6px 按钮） ================= */
.nav {
  position: fixed; inset: 0 0 auto 0; z-index: 100;
  height: var(--nav-h);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--hairline);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 100%; gap: 20px; }

.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--ink); font-weight: 600; font-size: 14px; letter-spacing: -0.2px; }
.brand:hover { color: var(--ink); text-decoration: none; }
.brand-mark {
  width: 24px; height: 24px; border-radius: var(--r-sm);
  background: var(--ink);
  position: relative;
}
.brand-mark::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(135deg, transparent 40%, rgba(255, 255, 255, 0.9) 40%, rgba(255, 255, 255, 0.9) 47%, transparent 47%);
  border-radius: inherit;
}
.brand-name { font-weight: 600; letter-spacing: -0.4px; }

.nav-links { display: flex; gap: 26px; align-items: center; }
.nav-links a { color: var(--body); font-size: 14px; font-weight: 400; }
.nav-links a:hover { color: var(--ink); text-decoration: none; }
.nav-links a.active { color: var(--ink); }

.nav-actions { display: flex; gap: 8px; align-items: center; }
.nav-toggle { display: none; background: var(--canvas); border: 1px solid var(--hairline); border-radius: var(--r-sm); color: var(--ink); width: 40px; height: 40px; cursor: pointer; font-size: 15px; }

/* ================= 按钮 ================= */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  font-family: var(--font-sans); cursor: pointer;
  transition: background 0.12s, border-color 0.12s, color 0.12s, opacity 0.12s;
}
/* 营销尺度：墨黑 / 白 pill（100px 圆角，约 48px 高） */
.btn-primary, .btn-secondary, .btn-ghost {
  font-size: 16px; font-weight: 500; line-height: 1.2;
  min-height: 48px; padding: 0 24px;
  border-radius: var(--r-pill);
}
.btn-primary { background: var(--ink); color: var(--on-primary); border: 1px solid var(--ink); }
.btn-primary:hover { background: #000; color: var(--on-primary); text-decoration: none; }
.btn-secondary { background: var(--canvas); color: var(--ink); border: 1px solid var(--hairline); }
.btn-secondary:hover { background: var(--canvas-soft-2); color: var(--ink); text-decoration: none; }
/* 次级中的次级：用于「查看源码」这类弱引导 */
.btn-ghost { background: transparent; color: var(--ink-soft, var(--ink)); border: 1px solid transparent; }
.btn-ghost:hover { background: var(--canvas-soft-2); color: var(--ink); text-decoration: none; }
/* 导航尺度：6px 方角（nav-cta） */
.btn-nav, .btn-nav-primary {
  font-size: 14px; font-weight: 500; line-height: 1.2;
  min-height: 32px; padding: 0 14px;
  border-radius: var(--r-sm);
}
.btn-nav { background: var(--canvas); color: var(--ink); border: 1px solid var(--hairline); }
.btn-nav:hover { background: var(--canvas-soft-2); color: var(--ink); text-decoration: none; }
.btn-nav-primary { background: var(--ink); color: var(--on-primary); border: 1px solid var(--ink); }
.btn-nav-primary:hover { background: #000; color: var(--on-primary); text-decoration: none; }

/* ================= Hero（Vercel hero-band：白底 + mesh gradient） ================= */
.hero { position: relative; background: var(--canvas); padding: calc(var(--nav-h) + 88px) 0 0; overflow: hidden; }
.hero-mesh {
  position: absolute; inset: 0 0 auto 0; height: 420px; z-index: 0;
  background:
    radial-gradient(560px 300px at 18% -10%, rgba(0, 124, 240, 0.14), transparent 65%),
    radial-gradient(500px 300px at 50% -16%, rgba(121, 40, 202, 0.10), transparent 65%),
    radial-gradient(560px 300px at 82% -10%, rgba(255, 0, 128, 0.10), transparent 65%),
    radial-gradient(420px 260px at 68% 8%, rgba(0, 223, 216, 0.08), transparent 65%);
}
.hero-copy { position: relative; z-index: 1; text-align: center; max-width: 760px; margin: 0 auto; }

.eyebrow {
  display: inline-block;
  font-family: var(--font-mono); font-size: 12px; font-weight: 400;
  letter-spacing: 0; color: var(--mute);
  padding: 4px 12px; border: 1px solid var(--hairline); border-radius: var(--r-full);
  background: var(--canvas);
  margin-bottom: 20px;
}
.sec-head .eyebrow { margin-bottom: 16px; }

.hero-copy h1 {
  font-size: 48px; font-weight: 600; line-height: 1.1;
  letter-spacing: -2.4px; color: var(--ink); margin-bottom: 20px;
}
.hero-copy .lead {
  font-size: 18px; color: var(--body); line-height: 1.55;
  max-width: 560px; margin: 0 auto 32px;
}
.hero-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.hero-points { list-style: none; margin-top: 28px; display: flex; justify-content: center; flex-wrap: wrap; gap: 12px 28px; }
.hero-points li { font-size: 14px; color: var(--body); display: inline-flex; align-items: center; gap: 8px; }
.tick { width: 8px; height: 8px; border-radius: 50%; background: var(--link); display: inline-block; }

/* ---- 产品面板（Vercel code-editor-mockup：墨黑极性翻转） ---- */
.app-panel {
  position: relative; z-index: 1;
  margin: 72px 0 0;
  background: var(--ink);
  border-radius: var(--r-md);
  padding: 24px;
  box-shadow: 0 16px 40px rgba(23, 23, 23, 0.18);
}
.app-bar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 0 14px; border-bottom: 1px solid rgba(255, 255, 255, 0.12);
  font-size: 13px; color: rgba(255, 255, 255, 0.55);
}
.app-bar .dots { display: flex; gap: 6px; }
.app-bar .dots i { width: 8px; height: 8px; border-radius: 50%; background: rgba(255, 255, 255, 0.2); display: block; }
.app-row {
  display: grid; grid-template-columns: 110px 1fr 80px 88px; gap: 16px; align-items: center;
  padding: 13px 4px; border-bottom: 1px solid rgba(255, 255, 255, 0.08); font-size: 13px;
}
.app-row:last-child { border-bottom: none; }
.app-row-head { padding: 12px 4px 8px; font-size: 11px; letter-spacing: 0.05em; text-transform: uppercase; color: rgba(255, 255, 255, 0.35); }
.app-row .code { font-family: var(--font-mono); color: #fff; }
.app-row .url { color: rgba(255, 255, 255, 0.55); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.app-row .clicks { font-family: var(--font-mono); color: rgba(255, 255, 255, 0.65); text-align: right; font-variant-numeric: tabular-nums; }
.badge {
  justify-self: end; font-family: var(--font-mono); font-size: 11px; font-weight: 400;
  padding: 2px 8px; border-radius: var(--r-full);
  background: rgba(255, 255, 255, 0.1); border: 1px solid rgba(255, 255, 255, 0.14);
}
.badge.ok { color: #4ade80; }
.badge.warn { color: #f5a623; }
.badge.err { color: #f87171; }

/* ================= 数据条 ================= */
.band { background: var(--canvas-soft); padding: 96px 0 0; }
.metrics {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 0;
  background: var(--canvas); border: 1px solid var(--hairline);
  border-radius: var(--r-md); padding: 28px 32px;
  box-shadow: var(--shadow-card);
}
.metric { display: flex; align-items: baseline; gap: 12px; justify-content: center; }
.metric + .metric { border-left: 1px solid var(--hairline); }
.metric b { font-size: 32px; font-weight: 600; letter-spacing: -1.2px; color: var(--ink); font-variant-numeric: tabular-nums; }
.metric span { font-size: 14px; color: var(--body); }

/* ================= 区块通用 ================= */
.section { padding: 96px 0; }
.sec-head { margin-bottom: 48px; }
.sec-head h2 { font-size: 32px; font-weight: 600; letter-spacing: -1.28px; color: var(--ink); margin-bottom: 12px; }
.sec-head p { font-size: 16px; color: var(--body); max-width: 560px; }

/* ================= 功能卡片（Vercel card-marketing：白卡 / 8px / stacked shadow） ================= */
.card-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.card {
  background: var(--canvas); border: 1px solid var(--hairline); border-radius: var(--r-md);
  padding: 24px;
  box-shadow: var(--shadow-card);
  transition: box-shadow 0.15s, border-color 0.15s;
}
.card:hover { box-shadow: var(--shadow-lift); border-color: var(--hairline-strong); }
.card .tags { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 16px; }
.tag {
  font-family: var(--font-mono); font-size: 11px; font-weight: 400;
  padding: 3px 8px; border-radius: var(--r-full);
  background: var(--canvas-soft); border: 1px solid var(--hairline); color: var(--body);
}
.card h3 { font-size: 18px; font-weight: 600; letter-spacing: -0.4px; margin-bottom: 8px; color: var(--ink); }
.card p { font-size: 14px; color: var(--body); line-height: 1.55; }

/* ================= 架构（Vercel showcase-band-dark：墨黑极性翻转） ================= */
.arch {
  background: var(--ink);
  border-radius: var(--r-md);
  padding: 32px; overflow-x: auto;
  box-shadow: 0 16px 40px rgba(23, 23, 23, 0.18);
}
.arch pre {
  font-family: var(--font-mono); font-size: 12.5px; line-height: 1.5;
  color: rgba(255, 255, 255, 0.45); min-width: 840px;
}
.arch pre b { color: #fff; font-weight: 500; }
.arch pre i { color: #8ab4f8; font-style: normal; }

/* ================= 快速开始（Vercel code-editor-mockup） ================= */
.quick-grid { display: grid; grid-template-columns: 1.2fr 1fr; gap: 16px; }
.code-block { background: var(--ink); border-radius: var(--r-md); overflow: hidden; box-shadow: 0 16px 40px rgba(23, 23, 23, 0.14); }
.code-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 10px 16px; border-bottom: 1px solid rgba(255, 255, 255, 0.12);
  font-size: 12px; color: rgba(255, 255, 255, 0.55);
}
.copy-btn {
  background: rgba(255, 255, 255, 0.08); border: 1px solid rgba(255, 255, 255, 0.16); border-radius: var(--r-xs);
  color: rgba(255, 255, 255, 0.75); font-size: 12px; padding: 4px 10px; cursor: pointer;
  font-family: var(--font-mono); transition: color 0.15s, border-color 0.15s, background 0.15s;
}
.copy-btn:hover { color: #fff; border-color: rgba(255, 255, 255, 0.4); background: rgba(255, 255, 255, 0.12); }
.copy-btn.ok { color: #4ade80; border-color: rgba(74, 222, 128, 0.5); }
.code-block pre { padding: 18px 20px; overflow-x: auto; font-family: var(--font-mono); font-size: 13px; line-height: 1.7; color: #d4d4d8; }
.code-block pre .cm { color: rgba(255, 255, 255, 0.35); }
.code-block pre .fn { color: #8ab4f8; }

/* ================= 文档 ================= */
.docs-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.doc-card {
  background: var(--canvas); border: 1px solid var(--hairline); border-radius: var(--r-md);
  padding: 24px; display: block;
  box-shadow: var(--shadow-card);
  transition: box-shadow 0.15s, border-color 0.15s;
}
.doc-card:hover { box-shadow: var(--shadow-lift); border-color: var(--hairline-strong); text-decoration: none; }
.doc-card h3 { font-size: 16px; font-weight: 600; margin-bottom: 6px; color: var(--ink); }
.doc-card p { font-size: 14px; color: var(--body); }
.doc-card .go { color: var(--link); font-family: var(--font-mono); font-size: 12px; font-weight: 500; display: inline-block; margin-top: 12px; }

/* ================= CTA ================= */
.cta-band { margin-top: 96px; background: var(--canvas); border: 1px solid var(--hairline); border-radius: var(--r-lg); padding: 48px; text-align: center; box-shadow: var(--shadow-card); }
.cta-band h2 { font-size: 32px; font-weight: 600; letter-spacing: -1.28px; margin-bottom: 24px; color: var(--ink); }

/* ================= 页脚（Vercel footer：白底 / mono caption） ================= */
.footer { background: var(--canvas); border-top: 1px solid var(--hairline); padding: 32px 0 40px; }
.footer-inner { display: flex; justify-content: space-between; align-items: center; gap: 20px; flex-wrap: wrap; }
.footer p { font-size: 13px; color: var(--mute); }
.footer b { color: var(--ink); font-weight: 600; }
.footer a { color: var(--mute); }
.footer a:hover { color: var(--link); }

/* ================= Reveal ================= */
.reveal { opacity: 0; transform: translateY(8px); transition: opacity 0.35s ease, transform 0.35s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ================= 响应式 ================= */
@media (max-width: 1024px) {
  .card-grid { grid-template-columns: repeat(2, 1fr); }
  .docs-grid { grid-template-columns: repeat(2, 1fr); }
  .quick-grid { grid-template-columns: 1fr; }
  .metric + .metric { border-left: none; }
  .metrics { gap: 20px 0; padding: 24px; }
  .metrics { grid-template-columns: repeat(2, 1fr); }
  .metric { justify-content: flex-start; }
  .hero-copy h1 { font-size: 40px; letter-spacing: -2px; }
  .sec-head h2 { font-size: 28px; letter-spacing: -1px; }
  .section { padding: 72px 0; }
  .band { padding: 72px 0 0; }
}
@media (max-width: 768px) {
  .nav-links {
    position: fixed; top: var(--nav-h); left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 0;
    background: var(--canvas); border-bottom: 1px solid var(--hairline);
    padding: 8px 24px 16px; display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 0; border-bottom: 1px solid var(--hairline); }
  .nav-actions { display: none; }
  .nav-toggle { display: block; }
  .hero { padding-top: calc(var(--nav-h) + 64px); }
  .hero-copy h1 { font-size: 32px; letter-spacing: -1.4px; }
  .sec-head h2 { font-size: 26px; }
  .card-grid, .docs-grid { grid-template-columns: 1fr; }
  .app-row { grid-template-columns: 96px 1fr; }
  .app-row-head { display: none; }
  .app-row .clicks, .app-row .badge { display: none; }
}
@media (max-width: 480px) {
  .container { padding: 0 16px; }
  .cta-band { padding: 32px 24px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation: none !important; transition: none !important; }
  .reveal { opacity: 1; transform: none; }
}