/* ===========================================================================
 * 云卷云舒 · 共享样式 —— 纸感编辑风（参考 knowledge.libo.run）
 * 纸底 #f5f0e5 · 墨色 #252018 · 砖红 #a43b27/#c7462b · 发丝线 #d4c7b6
 * 标题宋体衬线，正文黑体 1.7 行高；圆角 4~8px；不用投影，用细线分隔
 * 加载顺序：css/style.css → 页面内联 CSS（页面专属）
 * =========================================================================== */

/* ---------- CSS 变量 ---------- */
:root {
  --color-primary: #a43b27;
  --color-primary-dark: #873020;
  --color-secondary: #c7462b;
  --color-gradient: #a43b27;
  --color-dark: #252018;
  --color-text: #252018;
  --color-text-sub: #4a443b;
  --color-text-muted: #6a6155;
  --color-text-faint: #8a7f70;
  --color-bg: #f5f0e5;
  --color-bg-card: #fffdf8;
  --color-bg-soft: #f1ead9;
  --color-border: #d4c7b6;
  --color-border-dashed: #cbbca4;
  --color-gold: #b7791f;
  --color-bronze: #92610f;
  --color-success: #497952;

  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-pill: 4px;

  --shadow-sm: none;
  --shadow-md: none;
  --shadow-lg: none;

  --font-stack: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-serif: "Songti SC", "Songti TC", STSong, Georgia, serif;
  --size-snav-font: 15px;
  --size-h1: clamp(2rem, 4vw, 2.75rem);
  --size-h2: clamp(1.5rem, 3vw, 2rem);
  --size-body: 16px;
}

/* ---------- Reset ---------- */
* { box-sizing: border-box; }
body {
  font-family: var(--font-stack);
  background: var(--color-bg);
  margin: 0;
  padding: 0;
  color: var(--color-text);
  font-size: var(--size-body);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
a { color: var(--color-primary); text-decoration: underline; text-underline-offset: 4px; text-decoration-thickness: 1px; }
a:hover { color: var(--color-primary-dark); text-decoration-thickness: 2px; }
img { max-width: 100%; }
h1, h2, h3, h4 {
  font-family: var(--font-serif);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.01em;
}
:focus-visible { outline: 3px solid var(--color-primary); outline-offset: 2px; }

/* ---------- 容器 ---------- */
.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ---------- 顶部导航 ---------- */
.snav {
  display: flex;
  align-items: center;
  gap: 22px;
  padding: 14px 20px;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
}
.snav-home {
  color: var(--color-text);
  text-decoration: none;
  font-weight: 700;
  font-size: var(--size-snav-font);
  padding: 6px 0;
}
.snav-home.on { color: var(--color-primary); }
.snav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--color-text);
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 24px;
  letter-spacing: -0.02em;
  text-decoration: none;
  white-space: nowrap;
}
.snav-logo:hover { color: var(--color-text); }
.snav-logo .snav-seal {
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
  box-shadow: none;
}
.snav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 26px;
  font-size: var(--size-snav-font);
  align-items: center;
  margin-left: auto;
}
.snav-links a {
  color: var(--color-text);
  padding: 9px 0;
  font-weight: 600;
  font-size: 14px;
  text-decoration: none;
  line-height: 1.2;
}
.snav-links a:hover { color: var(--color-primary); }
.snav-links a.on { color: var(--color-primary); }
.snav-cta {
  background: transparent;
  color: var(--color-primary) !important;
  padding: 7px 17px;
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 14px;
  text-decoration: none;
  box-shadow: none;
  flex-shrink: 0;
}
.snav-cta:hover { background: #fff0e7; }
.snav-cta.logged {
  background: var(--color-success);
  border-color: var(--color-success);
  color: #fffdf8 !important;
}
.snav-cta.logged:hover { background: #3d6444; }

/* ---------- Hero 区 ---------- */
.hero {
  padding: 64px 20px 56px;
  text-align: center;
  background: transparent;
  border-bottom: 1px solid var(--color-border);
}
.hero h1 { font-size: var(--size-h1); margin: 0 0 20px; line-height: 1.25; letter-spacing: -0.02em; }
.hero h1 .hl { color: var(--color-primary); }
.hero .sub {
  font-size: 18px;
  color: var(--color-text-muted);
  margin: 0 auto 30px;
  max-width: 580px;
  line-height: 1.8;
}
.hero .sub b {
  color: var(--color-text);
  background: transparent;
  padding: 0;
  border-radius: 0;
  border-bottom: 2px solid var(--color-secondary);
  font-weight: 650;
}
.badge {
  display: inline-block;
  background: transparent;
  border: 1px solid var(--color-border);
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  color: var(--color-text-muted);
  letter-spacing: 0.04em;
  margin-bottom: 18px;
}
.hero-btns {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 10px 22px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  transition: background-color 150ms ease-out, border-color 150ms ease-out, transform 150ms ease-out;
  cursor: pointer;
  border: 1px solid var(--color-primary);
}
.btn:active { transform: scale(0.97); }
.btn.primary {
  background: var(--color-primary);
  color: #fffdf8;
  box-shadow: none;
}
.btn.primary:hover {
  background: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  transform: none;
  box-shadow: none;
  color: #fffdf8;
  text-decoration: none;
}
.btn.ghost {
  background: transparent;
  color: var(--color-primary);
  border: 1px solid var(--color-primary);
}
.btn.ghost:hover { background: #fff0e7; color: var(--color-primary); text-decoration: none; }
.hero-meta { margin-top: 20px; font-size: 14px; color: var(--color-text-faint); }

/* ---------- Section 通用 ---------- */
section { padding: 56px 20px; }
section.white { background: transparent; border-top: 1px solid var(--color-border); }
.section-title {
  font-size: var(--size-h2);
  text-align: center;
  margin: 0 0 10px;
}
.section-sub {
  font-size: 16px;
  color: var(--color-text-muted);
  text-align: center;
  margin: 0 0 34px;
  line-height: 1.7;
}

/* ---------- 卡片网格 ---------- */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 18px;
}
.card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 22px;
  box-shadow: none;
}
.card .icon { font-size: 28px; margin-bottom: 10px; }
.card h3 { font-size: 19px; margin: 0 0 8px; }
.card p { font-size: 15px; color: var(--color-text-muted); line-height: 1.8; margin: 0; }
.card .ref { margin-top: 10px; font-size: 13px; color: var(--color-text-faint); }
.f-card .ref b { color: var(--color-primary); }

/* ---------- 步骤 ---------- */
.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 26px;
}
.step {
  background: transparent;
  border: 0;
  border-top: 2px solid var(--color-text);
  border-radius: 0;
  padding: 20px 0 0;
  box-shadow: none;
}
.step .num {
  width: auto;
  height: auto;
  line-height: 1;
  text-align: left;
  background: transparent;
  color: var(--color-primary);
  border-radius: 0;
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.06em;
  font-variant-numeric: tabular-nums;
  margin-bottom: 14px;
  display: block;
}
.step h4 { font-size: 17px; margin: 0 0 6px; }
.step p { font-size: 14.5px; color: var(--color-text-muted); line-height: 1.8; margin: 0; }

/* ---------- 排行榜 ---------- */
.rank-box {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 16px;
  box-shadow: none;
}
.rank-row {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 0;
  border-bottom: 1px solid var(--color-bg-soft);
}
.rank-row:last-child { border-bottom: none; }
.rank-no { width: 30px; text-align: center; font-weight: 800; color: var(--color-text-faint); font-variant-numeric: tabular-nums; }
.rank-no.r1 { color: var(--color-gold); }
.rank-no.r2 { color: #a89d8c; }
.rank-no.r3 { color: var(--color-bronze); }
.rank-av {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--color-bg-soft);
  object-fit: cover;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.rank-av img { width: 100%; height: 100%; object-fit: cover; }
.rank-name { flex: 1; font-weight: 600; }
.rank-score { font-weight: 800; color: var(--color-text); margin-right: 8px; font-variant-numeric: tabular-nums; }
.rank-lv { font-size: 12px; padding: 2px 8px; border-radius: var(--radius-sm); background: var(--color-bg-soft); color: var(--color-primary); }
.rank-empty { padding: 24px; text-align: center; color: var(--color-text-faint); }

/* ---------- 邀请区 ---------- */
.invite-wrap {
  display: flex;
  gap: 34px;
  align-items: flex-start;
  flex-wrap: wrap;
  margin-top: 8px;
}
.invite-card { flex: 0 0 300px; max-width: 300px; }
.invite-card img {
  width: 100%;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  box-shadow: none;
  display: block;
}
.invite-tip {
  font-size: 13px;
  color: var(--color-text-faint);
  margin-top: 10px;
  text-align: center;
  line-height: 1.7;
}
.invite-side { flex: 1; min-width: 260px; }
.invite-h { font-size: 20px; font-weight: 700; margin-bottom: 10px; font-family: var(--font-serif); }
.invite-h2 { font-size: 14px; font-weight: 700; color: var(--color-text-muted); margin: 22px 0 9px; }
.invite-p { font-size: 15px; color: var(--color-text-muted); line-height: 1.85; margin-bottom: 20px; }
.invite-btn {
  display: block;
  width: 100%;
  text-align: center;
  background: transparent;
  color: var(--color-primary);
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  margin-bottom: 11px;
  transition: background-color 150ms ease-out;
  font-family: inherit;
}
.invite-btn:hover { background: #fff0e7; }
.invite-btn.primary {
  background: var(--color-primary);
  color: #fffdf8;
  border-color: var(--color-primary);
  box-shadow: none;
}
.invite-btn.primary:hover { background: var(--color-primary-dark); color: #fffdf8; filter: none; }
.invite-quote {
  background: var(--color-bg-soft);
  border: 1px dashed var(--color-border-dashed);
  border-radius: var(--radius-sm);
  padding: 13px 15px;
  font-size: 15px;
  color: var(--color-text-sub);
  line-height: 1.8;
  cursor: pointer;
  position: relative;
}
.invite-quote::after {
  content: "点一下复制";
  position: absolute;
  right: 12px;
  bottom: 9px;
  font-size: 11px;
  color: var(--color-text-faint);
}

/* ---------- FAQ ---------- */
.faq-section details,
.faq details {
  background: transparent;
  border: 0;
  border-bottom: 1px solid var(--color-border);
  border-radius: 0;
  padding: 16px 4px;
  margin-bottom: 0;
  box-shadow: none;
}
.faq-section summary,
.faq summary {
  font-weight: 650;
  cursor: pointer;
  font-size: 16px;
  outline: none;
  min-height: 32px;
  display: flex;
  align-items: center;
}
.faq-section summary::marker,
.faq summary::marker { color: var(--color-primary); }
.faq-section .a,
.faq .a {
  margin-top: 10px;
  font-size: 15px;
  color: var(--color-text-muted);
  line-height: 1.85;
}
.faq-section .a b,
.faq .a b { color: var(--color-text); }

/* ---------- About ---------- */
.about h3 { font-size: 20px; margin: 24px 0 12px; }
.about h3:first-child { margin-top: 0; }
.about p { font-size: 15.5px; color: var(--color-text-muted); line-height: 1.9; margin: 0 0 14px; }
.about p b { color: var(--color-text); }

/* ---------- Footer ---------- */
footer.site-footer {
  background: var(--color-bg);
  color: var(--color-text-muted);
  border-top: 1px solid var(--color-border);
  padding: 34px 20px 36px;
  margin-top: 40px;
  font-size: 14px;
  text-align: left;
}
footer.site-footer .sf-inner { max-width: 1080px; margin: 0 auto; }
footer.site-footer .sf-top {
  display: flex;
  gap: 30px;
  flex-wrap: wrap;
  justify-content: space-between;
  padding-bottom: 26px;
  border-bottom: 1px solid var(--color-border);
}
footer.site-footer .sf-brand { display: flex; align-items: center; gap: 12px; }
footer.site-footer .sf-seal {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
  box-shadow: none;
}
footer.site-footer .sf-logo {
  width: auto;
  min-width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  padding: 0 16px;
  background: transparent;
  border: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text);
  font-family: var(--font-serif);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 2px;
  white-space: nowrap;
  flex-shrink: 0;
  box-shadow: none;
}
footer.site-footer .sf-brand b { display: block; color: var(--color-text); font-family: var(--font-serif); font-size: 18px; font-weight: 700; letter-spacing: 0.5px; }
footer.site-footer .sf-brand span { display: block; font-size: 12.5px; color: var(--color-text-faint); margin-top: 3px; }
footer.site-footer .sf-cols { display: flex; gap: 52px; flex-wrap: wrap; justify-content: space-between; }
footer.site-footer .sf-cols h4 { color: var(--color-text); font-size: 13px; font-weight: 700; margin: 0 0 11px; }
footer.site-footer .sf-cols a { display: block; color: var(--color-text-muted); font-size: 14px; line-height: 2.05; text-decoration: none; }
footer.site-footer .sf-cols a:hover { color: var(--color-primary); text-decoration: underline; text-underline-offset: 4px; }
footer.site-footer .sf-bottom {
  padding-top: 20px;
  display: flex;
  justify-content: space-between;
  gap: 14px;
  flex-wrap: wrap;
  font-size: 12.5px;
  color: var(--color-text-faint);
  line-height: 1.9;
}
footer.site-footer .sf-bottom a { color: var(--color-text-muted); text-decoration: none; }
footer.site-footer .sf-bottom a:hover { color: var(--color-primary); }
footer.site-footer .sf-sep { margin: 0 8px; opacity: 0.4; }

/* ---------- Toast ---------- */
.toast {
  position: fixed;
  left: 50%;
  bottom: 60px;
  transform: translateX(-50%) translateY(20px);
  background: var(--color-dark);
  color: #fffdf8;
  padding: 12px 22px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 600;
  opacity: 0;
  pointer-events: none;
  transition: 0.25s;
  z-index: 9999;
}
.toast.on { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ---------- 小程序二维码 ---------- */
.promo { text-align: center; }
.promo h2 { font-size: var(--size-h2); margin: 0 0 8px; }
.qr-img {
  width: 240px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  box-shadow: none;
  margin: 8px 0 14px;
}
.promo-tip { font-size: 14px; color: var(--color-text-faint); }
.promo-tip b { color: var(--color-primary); }

/* ---------- 通用 utility ---------- */
.text-center { text-align: center; }
.mt-sm { margin-top: 12px; }
.mt-md { margin-top: 22px; }
.mt-lg { margin-top: 32px; }
.fs-sm { font-size: 13px; }
.fs-md { font-size: 15px; }
.fw-bold { font-weight: 700; }
.text-muted { color: var(--color-text-faint); }

/* ---------- 响应式 ---------- */
@media (max-width: 768px) {
  .snav { flex-wrap: wrap; padding: 10px 14px; }
  .snav-links { gap: 8px 16px; font-size: 14px; }
  .hero { padding: 44px 16px 40px; }
  .hero h1 { font-size: clamp(1.75rem, 7.5vw, 2.5rem); }
  .hero .sub { font-size: 16px; }
  .section-title { font-size: 24px; }
  .grid { grid-template-columns: 1fr; }
}
@media (max-width: 700px) {
  .snav-links { grid-template-columns: repeat(3, minmax(0, 1fr)); width: 100%; }
}
@media (max-width: 640px) {
  .invite-card { flex: 0 0 100%; max-width: 320px; margin: 0 auto; }
  footer.site-footer .sf-bottom { flex-direction: column; gap: 8px; align-items: center; text-align: center; }
  footer.site-footer .sf-sep { display: none; }
}