/* ================================================================
   shared.css — 跨页面公用样式
   设计 token 由 colors_and_type.css 提供
   ================================================================ */

* { box-sizing: border-box; }
html, body {
  margin: 0; padding: 0;
  font-family: var(--font-sans);
  color: var(--fg-default);
  background: var(--gray-25);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  font-feature-settings: "tnum" 1;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }

/* ----------------------------------------------------------------
   Buttons
   ---------------------------------------------------------------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  height: 40px; padding: 0 18px;
  border-radius: var(--radius-md);
  font-size: var(--text-md); font-weight: 500;
  border: 1px solid transparent;
  transition: background var(--duration-fast) var(--ease-standard),
              border-color var(--duration-fast) var(--ease-standard),
              color var(--duration-fast) var(--ease-standard);
  white-space: nowrap;
}
.btn-primary { background: var(--brand-500); color: #fff; }
.btn-primary:hover { background: var(--brand-600); }
.btn-primary:active { background: var(--brand-700); }
.btn-secondary { background: var(--gray-0); color: var(--brand-900); border-color: var(--border-default); }
.btn-secondary:hover { background: var(--gray-50); border-color: var(--border-strong); }
.btn-ghost { background: transparent; color: var(--fg-default); }
.btn-ghost:hover { background: var(--gray-100); }
.btn-lg { height: 48px; padding: 0 24px; font-size: var(--text-lg); }
.btn .icon { width: 18px; height: 18px; }

/* ----------------------------------------------------------------
   Layout helpers
   ---------------------------------------------------------------- */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 32px;
}
.section { padding: 96px 0; }
.section-tight { padding: 64px 0; }
.eyebrow {
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--brand-500);
  text-transform: uppercase;
  margin: 0 0 12px;
}
.section-title {
  font-size: var(--text-4xl);
  font-weight: 600;
  line-height: 1.18;
  letter-spacing: var(--tracking-cn-display);
  color: var(--brand-900);
  margin: 0 0 16px;
  max-width: 720px;
}
.section-sub {
  font-size: var(--text-lg);
  line-height: 1.6;
  color: var(--fg-muted);
  margin: 0;
  max-width: 640px;
}

/* ----------------------------------------------------------------
   Top Nav
   ---------------------------------------------------------------- */
.topnav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
}
.topnav-inner {
  height: 64px;
  display: flex; align-items: center; justify-content: space-between;
  max-width: 1440px; margin: 0 auto; padding: 0 32px;
}
.topnav-brand { display: flex; align-items: center; gap: 10px; }
.topnav-brand img { height: 32px; }
.topnav-links {
  display: flex; align-items: center; gap: 4px;
  font-size: var(--text-md); color: var(--gray-700);
}
.topnav-links a {
  padding: 8px 14px;
  border-radius: var(--radius-md);
  transition: background var(--duration-fast) var(--ease-standard);
}
.topnav-links a:hover { background: var(--gray-100); color: var(--brand-900); }
.topnav-cta { display: flex; gap: 10px; align-items: center; }

/* Nav user dropdown */
.nav-user { position: relative; }
.nav-user-btn {
  display: flex; align-items: center; gap: 8px;
  height: 36px; padding: 0 12px;
  background: var(--gray-0); border: 1px solid var(--border-default);
  border-radius: var(--radius-pill); cursor: pointer;
  font-size: var(--text-md); color: var(--gray-800); font-weight: 500;
  transition: border-color var(--duration-fast) var(--ease-standard);
}
.nav-user-btn:hover { border-color: var(--border-strong); }
.nav-avatar {
  width: 22px; height: 22px; border-radius: 50%;
  background: var(--brand-500); color: #fff;
  display: grid; place-items: center;
  font-size: 10px; font-weight: 700; flex-shrink: 0;
}
.nav-user-btn .icon { width: 14px; height: 14px; color: var(--fg-muted); }
.nav-dropdown {
  display: none; position: absolute; top: calc(100% + 8px); right: 0;
  min-width: 160px; background: var(--gray-0);
  border: 1px solid var(--border-default); border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg); overflow: hidden; z-index: 100;
}
.nav-dropdown.open { display: block; }
.nav-dropdown a, .nav-dropdown button {
  display: flex; align-items: center; gap: 8px;
  width: 100%; padding: 10px 14px;
  font-size: var(--text-sm); color: var(--gray-800);
  background: none; border: none; cursor: pointer;
  text-decoration: none; font-family: inherit;
  transition: background var(--duration-fast) var(--ease-standard);
}
.nav-dropdown a:hover, .nav-dropdown button:hover { background: var(--gray-50); }
.nav-dropdown .icon { width: 14px; height: 14px; color: var(--fg-muted); }
.nav-dropdown-divider { height: 1px; background: var(--border-subtle); margin: 4px 0; }
.nav-dropdown .logout { color: var(--danger-600); }

/* ----------------------------------------------------------------
   Footer
   ---------------------------------------------------------------- */
footer {
  background: var(--gray-25);
  border-top: 1px solid var(--border-subtle);
  padding: 64px 0 40px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr repeat(4, 1fr);
  gap: 48px;
  margin-bottom: 48px;
}
.footer-brand img { height: 32px; margin-bottom: 16px; }
.footer-brand p { margin: 0 0 16px; max-width: 320px; line-height: 1.6; color: var(--fg-muted); }
.footer-contact { font-size: var(--text-sm); color: var(--gray-700); line-height: 1.8; }
.footer-col h5 {
  font-size: var(--text-xs); font-weight: 600;
  color: var(--brand-900); letter-spacing: 0.06em;
  margin: 0 0 16px; text-transform: uppercase;
}
.footer-col ul { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 10px; }
.footer-col li a { color: var(--gray-600); }
.footer-col li a:hover { color: var(--brand-500); }
.footer-bottom {
  border-top: 1px solid var(--border-subtle); padding-top: 24px;
  display: flex; justify-content: space-between;
  font-size: var(--text-xs); color: var(--fg-subtle);
}

/* ----------------------------------------------------------------
   Responsive
   ---------------------------------------------------------------- */
@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .container { padding: 0 20px; }
}