/* ============================================================
   微信年轮 · 官网共享样式
   纯 CSS：无外部资源、无第三方字体、仅系统字体栈
   桌面优先，移动可读
   ============================================================ */

:root {
  --bg: #f6f8f3;
  --surface: #ffffff;
  --surface-soft: #edf3ea;
  --ink: #17211b;
  --muted: #5b6b60;
  --faint: #87938a;
  --accent: #07c160;
  --accent-strong: #059e50;
  --accent-dark: #067a3e;
  --accent-soft: #e2f5e9;
  --line: #dfe7dd;
  --warn-bg: #fff7e6;
  --warn-line: #efdcab;
  --warn-ink: #7d5500;
  --code-bg: #eef1ea;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow-card: 0 1px 2px rgba(23, 33, 27, .05), 0 10px 28px rgba(23, 33, 27, .07);
  --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Noto Sans CJK SC", "Source Han Sans SC", "Segoe UI", sans-serif;
  --font-mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, "PingFang SC", monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.75;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection { background: rgba(7, 193, 96, .22); }

a { color: var(--accent-dark); text-decoration: underline; text-underline-offset: 3px; }
a:hover { color: var(--accent-strong); }

img, svg { max-width: 100%; }

:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------------- 顶栏 ---------------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(246, 248, 243, .92);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 18px;
  flex-wrap: wrap;
  max-width: 1100px;
  margin: 0 auto;
  padding: 12px 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 9px;
  font-size: 19px;
  font-weight: 700;
  color: var(--ink);
  text-decoration: none;
}

.brand:hover { color: var(--ink); }

.brand .ver {
  font-size: 12px;
  font-weight: 600;
  color: var(--accent-dark);
  background: var(--accent-soft);
  border: 1px solid #c8ecd4;
  padding: 2px 8px;
  border-radius: 999px;
  line-height: 1.4;
}

.nav {
  display: flex;
  align-items: center;
  gap: 2px;
  margin-left: auto;
  flex-wrap: wrap;
}

.nav a {
  display: inline-block;
  color: var(--muted);
  text-decoration: none;
  padding: 7px 12px;
  border-radius: 8px;
  font-size: 15.5px;
}

.nav a:hover { color: var(--ink); background: rgba(7, 193, 96, .09); }

.nav a[aria-current="page"] { color: var(--accent-dark); font-weight: 600; }

/* ---------------- 按钮 ---------------- */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border-radius: 999px;
  padding: 12px 26px;
  font-size: 16px;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
  transition: background .15s ease, color .15s ease, border-color .15s ease;
}

.btn-sm { padding: 8px 18px; font-size: 15px; }

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 6px 16px rgba(7, 193, 96, .28);
}

.btn-primary:hover { background: var(--accent-strong); color: #fff; }

.btn-outline {
  background: var(--surface);
  border-color: var(--line);
  color: var(--ink);
}

.btn-outline:hover { border-color: var(--accent); color: var(--accent-dark); }

/* ---------------- Hero ---------------- */

.hero { padding: 84px 0 56px; text-align: center; }

.hero .badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  background: var(--accent-soft);
  border: 1px solid #c8ecd4;
  color: var(--accent-dark);
  padding: 6px 16px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 600;
}

.hero h1 {
  font-size: clamp(31px, 5vw, 50px);
  line-height: 1.28;
  letter-spacing: .01em;
  margin: 26px auto 18px;
  max-width: 18em;
}

.hero .lead {
  font-size: 18px;
  color: var(--muted);
  max-width: 42em;
  margin: 0 auto 34px;
}

.hero .actions {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

.hero .honest-line {
  margin: 26px auto 0;
  max-width: 40em;
  font-size: 14.5px;
  color: var(--muted);
}

.hero .honest-line strong { color: var(--warn-ink); }

/* ---------------- 通用分区 ---------------- */

.section { padding: 64px 0; }

.section--tint { background: var(--surface-soft); }

.section--center { text-align: center; }

.section-title {
  font-size: 28px;
  line-height: 1.35;
  margin: 0 0 10px;
}

.section-sub {
  color: var(--muted);
  margin: 0 0 38px;
  max-width: 46em;
}

.section--center .section-sub { margin-left: auto; margin-right: auto; }

.section-note {
  text-align: center;
  color: var(--muted);
  font-size: 15.5px;
  margin: 34px 0 0;
}

/* ---------------- 能力卡片 ---------------- */

.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px 26px;
  box-shadow: var(--shadow-card);
}

.card--privacy {
  background: linear-gradient(180deg, #f0faf3 0%, #ffffff 62%);
}

.card .icon {
  width: 46px;
  height: 46px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent-soft);
  margin-bottom: 16px;
}

.card h3 { margin: 0 0 10px; font-size: 19px; }

.card ul { margin: 0; padding-left: 1.15em; color: var(--muted); font-size: 15.5px; }
.card li { margin: 7px 0; }
.card li::marker { color: var(--accent); }

.more-capabilities {
  margin: 26px auto 0;
  max-width: 52em;
  text-align: center;
  color: var(--muted);
  font-size: 15px;
}

/* ---------------- 使用三步 ---------------- */

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.step {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px 26px 26px;
  box-shadow: var(--shadow-card);
}

.step .num {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  font-weight: 700;
  font-size: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
}

.step h3 { margin: 0 0 8px; font-size: 17.5px; }

.step p { margin: 0; color: var(--muted); font-size: 15.5px; }

/* ---------------- 诚实说明区 ---------------- */

.honest {
  background: var(--warn-bg);
  border: 1px solid var(--warn-line);
  border-radius: var(--radius);
  padding: 38px 38px 30px;
}

.honest h2 { margin: 0 0 8px; font-size: 24px; color: var(--warn-ink); }

.honest .honest-lead { margin: 0 0 26px; color: #6b4d12; font-size: 15.5px; }

.honest-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px 30px;
}

.honest-item { font-size: 15px; color: #5c4516; }

.honest-item .mark {
  display: block;
  font-weight: 700;
  color: var(--warn-ink);
  margin-bottom: 2px;
}

/* ---------------- 下载区 ---------------- */

.download {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 46px 40px;
  text-align: center;
  box-shadow: var(--shadow-card);
}

.ver-chip {
  display: inline-block;
  background: var(--accent-soft);
  border: 1px solid #c8ecd4;
  color: var(--accent-dark);
  font-weight: 600;
  font-size: 14px;
  padding: 4px 14px;
  border-radius: 999px;
}

.download h2 { margin: 18px 0 8px; font-size: 27px; }

.dl-meta {
  list-style: none;
  margin: 0 0 26px;
  padding: 0;
  display: flex;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
}

.dl-meta li {
  background: var(--surface-soft);
  border-radius: 999px;
  padding: 4px 14px;
  font-size: 14px;
  color: var(--muted);
}

.download .btn { font-size: 16.5px; }

.sha {
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.6;
  text-align: left;
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  word-break: break-all;
  max-width: 660px;
  margin: 22px auto 0;
}

.sha .label {
  display: block;
  font-family: var(--font-sans);
  color: var(--faint);
  font-size: 12.5px;
  margin-bottom: 5px;
}

.sign-note {
  background: var(--warn-bg);
  border: 1px solid var(--warn-line);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  text-align: left;
  font-size: 14.5px;
  color: var(--warn-ink);
  max-width: 700px;
  margin: 20px auto 0;
}

/* ---------------- 页脚 ---------------- */

.site-footer {
  border-top: 1px solid var(--line);
  background: #f0f3ec;
  margin-top: 24px;
  padding: 46px 0 54px;
  color: var(--muted);
  font-size: 14.5px;
}

.footer-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 22px 56px;
  justify-content: space-between;
  align-items: flex-start;
}

.footer-grid p { margin: 0 0 6px; }

.footer-links {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}

.footer-links a { color: var(--accent-dark); }

.disclaimer {
  margin-top: 20px;
  color: var(--faint);
  font-size: 13.5px;
}

/* ---------------- 子页面 ---------------- */

.page-head { padding: 58px 0 6px; text-align: center; }

.page-head h1 {
  font-size: clamp(27px, 4vw, 38px);
  line-height: 1.3;
  margin: 0 0 12px;
}

.page-head .lead {
  color: var(--muted);
  font-size: 17px;
  max-width: 46em;
  margin: 0 auto;
}

.page-body { padding: 30px 0 10px; }

.guide-section {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 30px 34px;
  margin: 28px 0;
  box-shadow: var(--shadow-card);
}

.guide-section h2 {
  font-size: 21px;
  margin: 0 0 4px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.guide-section h2 .num-dot {
  flex: none;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  font-size: 15px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}

.guide-section .section-lead { color: var(--muted); margin: 0 0 14px; font-size: 15.5px; }

.guide-steps {
  list-style: none;
  margin: 12px 0 0;
  padding: 0;
  counter-reset: gs;
}

.guide-steps li {
  counter-increment: gs;
  position: relative;
  padding-left: 42px;
  margin: 15px 0;
  color: var(--muted);
  font-size: 15.5px;
}

.guide-steps li::before {
  content: counter(gs);
  position: absolute;
  left: 0;
  top: 3px;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent-dark);
  font-weight: 700;
  font-size: 13.5px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.note-box {
  margin-top: 18px;
  background: var(--surface-soft);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 12px 16px;
  font-size: 14.5px;
  color: var(--muted);
}

.warn-box {
  background: var(--warn-bg);
  border: 1px solid var(--warn-line);
  border-radius: var(--radius-sm);
  padding: 14px 18px;
  font-size: 14.5px;
  color: var(--warn-ink);
  margin-top: 16px;
}

.path {
  font-family: var(--font-mono);
  font-size: .9em;
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 0 7px;
  white-space: nowrap;
}

/* FAQ */

.faq details {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 17px 22px;
  margin: 12px 0;
  box-shadow: 0 1px 2px rgba(23, 33, 27, .04);
}

.faq summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--ink);
  font-size: 16px;
}

.faq summary::marker { color: var(--accent); }

.faq details[open] summary { margin-bottom: 6px; }

.faq details p {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 15px;
}

/* 更新日志 */

.versions { margin-top: 14px; }

.version {
  background: var(--surface);
  border: 1px solid var(--line);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius-sm);
  padding: 22px 26px;
  margin: 16px 0;
}

.version h2 { font-size: 19px; margin: 0 0 2px; }

.version .tag-new {
  display: inline-block;
  vertical-align: 2px;
  margin-left: 8px;
  background: var(--accent);
  color: #fff;
  font-size: 12px;
  font-weight: 600;
  border-radius: 999px;
  padding: 1px 9px;
}

.version .date { color: var(--faint); font-size: 14px; margin: 0 0 10px; }

.version ul { margin: 0; padding-left: 1.2em; color: var(--muted); font-size: 15.5px; }
.version li { margin: 5px 0; }
.version li::marker { color: var(--accent); }

/* ---------------- 响应式 ---------------- */

@media (max-width: 920px) {
  .cards, .steps, .honest-grid { grid-template-columns: 1fr 1fr; }
  .cards .card--privacy { grid-column: 1 / -1; }
}

@media (max-width: 640px) {
  body { font-size: 16px; }

  .header-inner { padding: 10px 16px; gap: 10px; }
  .nav { order: 3; width: 100%; justify-content: center; }
  .nav .btn { margin-left: 6px; }

  .hero { padding: 56px 0 40px; }
  .hero h1 { margin-top: 20px; }

  .section { padding: 44px 0; }
  .section-title { font-size: 24px; }

  .cards, .steps, .honest-grid { grid-template-columns: 1fr; }
  .cards .card--privacy { grid-column: auto; }

  .honest { padding: 28px 22px 22px; }

  .download { padding: 34px 20px; }
  .download .btn { width: 100%; justify-content: center; }

  .guide-section { padding: 24px 20px; }

  .footer-grid { flex-direction: column; gap: 16px; }
}