/* DayFlow · 官网 · 全站样式
   ---------------------------------------
   设计原则：
   - 极简 · 大量留白 · 深色主色调 (#0A1744) 与品牌 App 一致
   - 无 JS 依赖也能读，任何浏览器都能开
   - 响应式：<640px 单栏，≥640px 三栏
*/

:root {
  --primary: #0A1744;
  --primary-2: #1E293B;
  --accent: #2563EB;
  --ink: #0F172A;
  --ink2: #334155;
  --muted: #64748B;
  --divider: #E2E8F0;
  --surface: #FFFFFF;
  --bg: #F8FAFC;
  --danger: #DC2626;
  --success: #059669;
  --radius: 12px;
  --radius-lg: 20px;
  --shadow: 0 2px 8px rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 8px 32px rgba(15, 23, 42, 0.12);
  --max-w: 1100px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

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

/* ─── Header ─────────────────────────── */
header {
  background: var(--surface);
  border-bottom: 1px solid var(--divider);
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: saturate(180%) blur(10px);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 18px;
  color: var(--primary);
  text-decoration: none;
}
.brand-mark {
  width: 32px;
  height: 32px;
  background: var(--primary);
  color: #fff;
  border-radius: 8px;
  display: grid;
  place-items: center;
  font-weight: 700;
  font-size: 18px;
}
.nav-links {
  display: flex;
  gap: 24px;
  font-size: 14px;
}
.nav-links a {
  color: var(--ink2);
  text-decoration: none;
}
.nav-links a:hover {
  color: var(--primary);
}

/* ─── Hero ─────────────────────────── */
.hero {
  padding: 80px 0 60px;
  text-align: center;
}
.hero h1 {
  font-size: 44px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 18px;
  line-height: 1.2;
}
.hero .sub {
  font-size: 18px;
  color: var(--ink2);
  margin-bottom: 32px;
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
}
.hero .badges {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 40px;
}
.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: var(--surface);
  border: 1px solid var(--divider);
  border-radius: 100px;
  font-size: 13px;
  color: var(--ink2);
}

.cta {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 500;
  text-decoration: none;
  transition: transform 0.15s, box-shadow 0.15s;
  border: none;
  cursor: pointer;
}
.btn-primary {
  background: var(--primary);
  color: #fff;
}
.btn-primary:hover {
  text-decoration: none;
  transform: translateY(-1px);
  box-shadow: var(--shadow-lg);
}
.btn-outline {
  background: var(--surface);
  color: var(--primary);
  border: 1.5px solid var(--divider);
}
.btn-outline:hover {
  text-decoration: none;
  border-color: var(--primary);
}

/* ─── Features Section ─────────────────────────── */
.section {
  padding: 60px 0;
}
.section h2 {
  font-size: 28px;
  font-weight: 700;
  color: var(--primary);
  text-align: center;
  margin-bottom: 12px;
}
.section .lead {
  font-size: 15px;
  color: var(--muted);
  text-align: center;
  margin-bottom: 48px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
@media (max-width: 800px) {
  .grid-3 { grid-template-columns: 1fr; }
}

.card {
  background: var(--surface);
  border: 1px solid var(--divider);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: transform 0.15s, box-shadow 0.15s;
}
.card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}
.card-icon {
  width: 44px;
  height: 44px;
  background: rgba(37, 99, 235, 0.08);
  border-radius: 10px;
  display: grid;
  place-items: center;
  font-size: 22px;
  margin-bottom: 14px;
}
.card h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--ink);
}
.card p {
  font-size: 14px;
  color: var(--ink2);
  line-height: 1.6;
}

/* ─── Privacy Promise ─────────────────────────── */
.promise {
  background: var(--primary);
  color: #fff;
  padding: 60px 0;
  margin: 40px 0;
}
.promise h2 {
  color: #fff;
  font-size: 28px;
  margin-bottom: 32px;
  text-align: center;
}
.promise-list {
  max-width: 640px;
  margin: 0 auto;
  list-style: none;
}
.promise-list li {
  padding: 10px 0;
  font-size: 15px;
  display: flex;
  align-items: flex-start;
  gap: 10px;
  opacity: 0.95;
}
.promise-list li::before {
  content: "✓";
  color: #4ADE80;
  font-weight: 700;
  flex-shrink: 0;
  margin-top: 2px;
}

/* ─── Footer ─────────────────────────── */
footer {
  background: var(--surface);
  border-top: 1px solid var(--divider);
  padding: 32px 0;
  margin-top: 60px;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 14px;
  font-size: 13px;
  color: var(--muted);
}
.footer-inner a {
  color: var(--muted);
  margin: 0 8px;
}
.footer-inner a:hover {
  color: var(--primary);
}

/* ─── Legal / Manual Page ─────────────────────────── */
.doc {
  background: var(--surface);
  border-radius: var(--radius-lg);
  padding: 48px 32px;
  margin: 40px 0;
  box-shadow: var(--shadow);
  line-height: 1.75;
}
.doc h1 {
  color: var(--primary);
  font-size: 32px;
  margin-bottom: 8px;
}
.doc .meta {
  color: var(--muted);
  font-size: 14px;
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--divider);
}
.doc h2 {
  color: var(--primary);
  font-size: 20px;
  margin: 32px 0 12px;
  padding-top: 12px;
}
.doc h3 {
  color: var(--ink);
  font-size: 16px;
  margin: 20px 0 8px;
  font-weight: 600;
}
.doc p {
  color: var(--ink2);
  margin-bottom: 12px;
}
.doc ul {
  color: var(--ink2);
  padding-left: 20px;
  margin-bottom: 12px;
}
.doc ul li { margin: 4px 0; }
.doc .callout {
  background: rgba(37, 99, 235, 0.06);
  border-left: 3px solid var(--accent);
  padding: 12px 16px;
  border-radius: 6px;
  color: var(--ink2);
  margin: 16px 0;
}
.doc hr {
  border: 0;
  border-top: 1px solid var(--divider);
  margin: 24px 0;
}
.doc .anchor-nav {
  background: var(--bg);
  border-radius: var(--radius);
  padding: 14px 18px;
  margin-bottom: 24px;
  font-size: 13px;
}
.doc .anchor-nav a {
  display: inline-block;
  margin-right: 12px;
  color: var(--ink2);
}

/* ─── Small tweaks ─────────────────────────── */
@media (max-width: 640px) {
  .container { padding: 0 16px; }

  /* Header - 顶栏导航压缩 */
  header { position: static; }  /* 移动端不 sticky，避免遮挡 */
  .nav {
    padding: 10px 0;
    flex-direction: column;
    align-items: center;
    gap: 8px;
  }
  .brand { font-size: 15px; gap: 8px; }
  .brand-mark { width: 26px; height: 26px; font-size: 14px; border-radius: 6px; }
  .nav-links {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 16px;
    font-size: 13px;
    white-space: nowrap;   /* 关键：单个链接内部不换行 */
    padding-top: 2px;
  }
  .nav-links a { white-space: nowrap; }

  /* Hero */
  .hero { padding: 40px 0 32px; }
  .hero h1 { font-size: 28px; line-height: 1.25; }
  .hero .sub { font-size: 15px; margin-bottom: 22px; padding: 0 4px; }
  .hero .badges { gap: 8px; margin-bottom: 28px; }
  .badge { font-size: 12px; padding: 5px 10px; }
  .cta { gap: 10px; }
  .btn { padding: 11px 18px; font-size: 14px; width: 100%; justify-content: center; }
  .cta .btn { flex: 1 1 100%; }

  /* Section */
  .section { padding: 40px 0; }
  .section h2 { font-size: 22px; }
  .section .lead { font-size: 14px; margin-bottom: 28px; }
  .grid-3 { gap: 14px; }
  .card { padding: 20px; border-radius: 16px; }
  .card h3 { font-size: 16px; }
  .card p { font-size: 13.5px; }

  /* Promise */
  .promise { padding: 40px 0; margin: 24px 0; }
  .promise h2 { font-size: 22px; margin-bottom: 20px; }
  .promise-list li { font-size: 14px; }

  /* Footer */
  footer { padding: 24px 0; margin-top: 40px; }
  .footer-inner {
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 10px;
    font-size: 12px;
  }
  .footer-inner a { margin: 0 6px; }

  /* Doc pages（隐私 / 手册 / 支持 / 条款） */
  .doc { padding: 24px 18px; margin: 20px 0; border-radius: 14px; }
  .doc h1 { font-size: 24px; }
  .doc h2 { font-size: 17px; margin: 24px 0 10px; }
  .doc h3 { font-size: 15px; }
  .doc p, .doc ul { font-size: 14px; }
  .doc .anchor-nav { font-size: 12px; padding: 10px 14px; }
  .doc .anchor-nav a { margin-right: 10px; margin-bottom: 4px; }
  .doc .callout { font-size: 13px; padding: 10px 14px; }
}

/* iOS 小屏 (iPhone SE 375px 及以下) */
@media (max-width: 380px) {
  .hero h1 { font-size: 24px; }
  .brand { font-size: 14px; }
  .nav-links { gap: 10px; font-size: 12px; }
}