/* ═══════════════════════════════════════════════════════════════
   PAPER 共享基础样式 — 所有页面共用
   设计系统: 学术蓝 · 专业 · 信任 · 合规
   最后更新: 2026-07-22
   ═══════════════════════════════════════════════════════════════ */

/* ── CSS 变量（与 V8 设计系统统一）── */
:root {
  --white: #ffffff;
  --bg: #f8f9fb;
  --surface: #ffffff;
  --border: #e8ecf1;
  --border-light: #f1f4f7;

  --text: #14181f;
  --text-secondary: #5a6475;
  --text-tertiary: #949eae;

  --brand: #1a3658;
  --brand-light: #234b78;
  --brand-pale: #e8eff7;

  --gold: #b8942d;
  --gold-light: #f5ecd7;
  --gold-dark: #8b6914;

  --green: #2d7a4a;
  --green-bg: #eaf5ef;
  --red: #c0392b;
  --red-bg: #fdf0ef;

  --shadow-sm: 0 1px 3px rgba(20,24,31,0.06);
  --shadow-md: 0 4px 16px rgba(20,24,31,0.08);
  --shadow-lg: 0 8px 32px rgba(20,24,31,0.10);

  --serif: "Noto Serif SC", "STSong", "SimSun", serif;
  --sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --num: "Inter", "JetBrains Mono", monospace;

  --radius: 8px;
  --radius-sm: 6px;
  --radius-lg: 12px;
}

/* ── Reset ── */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;font-size:16px}
body{
  font-family:var(--sans);
  background:var(--white);
  color:var(--text);
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
}
a{color:inherit;text-decoration:none}
button{cursor:pointer;font-family:inherit;border:none;background:none}
img{max-width:100%;height:auto;display:block}

/* ── Layout ── */
.wrap{max-width:1200px;margin:0 auto;padding:0 48px}

/* ── Buttons ── */
.btn{
  display:inline-flex;align-items:center;justify-content:center;
  height:44px;padding:0 24px;
  font-size:14px;font-weight:600;
  border-radius:var(--radius-sm);
  transition:all 0.2s ease;
  font-family:var(--sans);
  letter-spacing:.01em;
  gap:8px;
  white-space:nowrap;
}
.btn-outline{
  color:var(--brand);background:transparent;
  border:1.5px solid var(--border);
}
.btn-outline:hover{border-color:var(--brand);background:var(--brand-pale)}
.btn-primary{
  color:#fff;background:var(--brand);
  border:1.5px solid var(--brand);
  box-shadow:0 2px 8px rgba(26,54,88,0.18);
}
.btn-primary:hover{
  background:var(--brand-light);
  transform:translateY(-1px);
  box-shadow:0 4px 14px rgba(26,54,88,0.25);
}

/* ── 共享导航栏（.site-nav）── */
.site-nav{
  position:sticky;top:0;z-index:100;
  height:64px;
  background:rgba(255,255,255,0.96);
  backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);
  border-bottom:1px solid var(--border);
  box-shadow:0 1px 8px rgba(20,24,31,0.04);
  display:flex;align-items:center;
}
.site-nav .nav-inner{
  max-width:1200px;margin:0 auto;padding:0 48px;
  display:flex;align-items:center;justify-content:space-between;
  width:100%;height:100%;
}
.site-nav .nav-brand{
  display:flex;align-items:center;gap:8px;
  font-family:var(--serif);font-weight:700;font-size:17px;
  color:var(--brand);letter-spacing:.02em;flex-shrink:0;
}
.site-nav .nav-brand img{width:32px;height:32px;border-radius:6px}
.site-nav .nav-back{
  font-size:13px;color:var(--text-secondary);text-decoration:none;
  transition:color 0.15s;
}
.site-nav .nav-back:hover{color:var(--brand)}

/* ── 共享面包屑 ── */
.site-breadcrumb{
  max-width:1200px;margin:0 auto;padding:16px 48px 0;
  font-size:12px;color:var(--text-tertiary);
}
.site-breadcrumb a{color:var(--text-secondary);text-decoration:none}
.site-breadcrumb a:hover{color:var(--brand)}

/* ── 共享页脚 ── */
.site-footer{
  padding:40px 0;
  border-top:1px solid var(--border-light);
  font-size:13px;color:var(--text-tertiary);
  margin-top:64px;
}
.site-footer .footer-top{
  display:flex;align-items:center;justify-content:space-between;
  flex-wrap:wrap;gap:16px;margin-bottom:24px;
}
.site-footer .footer-links{
  display:flex;gap:24px;list-style:none;flex-wrap:wrap;
}
.site-footer .footer-links a{transition:color 0.15s}
.site-footer .footer-links a:hover{color:var(--text-secondary)}
.site-footer .footer-disclaimer{
  font-size:12px;line-height:1.9;color:var(--text-tertiary);
  margin-bottom:16px;
}
.site-footer .footer-bottom{
  text-align:center;padding-top:16px;
  font-size:11px;color:var(--text-tertiary);line-height:2;
}
.site-footer .footer-bottom a{color:var(--text-tertiary)}

/* ── 响应式 ── */
@media(max-width:768px){
  .wrap,.site-nav .nav-inner,.site-breadcrumb{padding-left:20px;padding-right:20px}
  .site-footer .footer-top{flex-direction:column;text-align:center}
}