:root {
  --bg1: #eef2ff;
  --bg2: #fdf2f8;
  --card: rgba(255, 255, 255, .82);
  --text: #1e293b;
  --muted: #64748b;
  --border: rgba(100, 116, 139, .18);
  --accent1: #0d9488;
  --accent2: #2563eb;
  --shadow: 0 10px 30px rgba(30, 41, 59, .10);
  --danger: #dc2626;
  --danger-bg: #fef2f2;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg1: #0f172a;
    --bg2: #1e1b4b;
    --card: rgba(30, 41, 59, .72);
    --text: #e2e8f0;
    --muted: #94a3b8;
    --border: rgba(148, 163, 184, .22);
    --shadow: 0 10px 30px rgba(0, 0, 0, .35);
    --danger: #f87171;
    --danger-bg: rgba(220, 38, 38, .16);
  }
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  min-height: 100vh;
  font-family: -apple-system, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: linear-gradient(135deg, var(--bg1), var(--bg2));
}
a { color: inherit; text-decoration: none; }
.page-center {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 24px 16px;
}
.brand { text-align: center; margin-bottom: 28px; }
.brand-mark {
  width: 64px; height: 64px; margin: 0 auto 12px;
  display: flex; align-items: center; justify-content: center;
  border-radius: 18px; color: #fff; font-size: 30px; font-weight: 700;
  background: linear-gradient(135deg, var(--accent1), var(--accent2));
  box-shadow: var(--shadow);
}
.brand-mark.small { width: 30px; height: 30px; font-size: 15px; border-radius: 9px; margin: 0; }
.brand h1 { margin: 0; font-size: 30px; letter-spacing: .04em; }
.brand-sub { margin: 6px 0 0; color: var(--muted); font-size: 14px; }
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 20px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(8px);
}
.login-card { width: 100%; max-width: 380px; padding: 28px 26px; }
.login-card label { display: block; font-size: 14px; margin-bottom: 16px; color: var(--muted); }
.login-card input[type="text"], .login-card input[type="password"] {
  display: block; width: 100%; margin-top: 6px; padding: 11px 12px;
  font-size: 15px; color: var(--text);
  background: transparent; border: 1px solid var(--border); border-radius: 10px;
  outline: none;
}
.login-card input:focus { border-color: var(--accent1); box-shadow: 0 0 0 3px rgba(13, 148, 136, .18); }
.btn-primary {
  width: 100%; padding: 12px; border: 0; border-radius: 12px;
  font-size: 16px; font-weight: 600; color: #fff; cursor: pointer;
  background: linear-gradient(135deg, var(--accent1), var(--accent2));
}
.btn-primary:hover { filter: brightness(1.07); }
.error {
  margin: 0 0 16px; padding: 10px 12px; border-radius: 10px;
  color: var(--danger); background: var(--danger-bg); font-size: 14px;
}
.foot { color: var(--muted); font-size: 13px; margin: 18px 0 0; }
.topbar {
  display: flex; align-items: center; justify-content: space-between;
  max-width: 960px; margin: 0 auto; padding: 18px 20px;
}
.brand-mini { display: flex; align-items: center; gap: 9px; font-weight: 700; font-size: 17px; }
.user-area { display: flex; align-items: center; gap: 10px; }
.user-capsule {
  padding: 7px 13px; border-radius: 999px; font-size: 14px;
  background: var(--card); border: 1px solid var(--border); box-shadow: var(--shadow);
}
.logout-form { margin: 0; }
.btn-ghost {
  padding: 7px 14px; border-radius: 999px; font-size: 14px; cursor: pointer;
  color: var(--text); background: var(--card); border: 1px solid var(--border);
}
.btn-ghost:hover { border-color: var(--accent1); color: var(--accent1); }
.nav-main { max-width: 960px; margin: 0 auto; padding: 30px 20px 60px; }
.cards { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-top: 8px; }
.site-card {
  display: flex; align-items: center; gap: 16px;
  padding: 26px 22px; border-radius: 20px;
  background: var(--card); border: 1px solid var(--border); box-shadow: var(--shadow);
  backdrop-filter: blur(8px);
  transition: transform .18s ease, box-shadow .18s ease;
}
.site-card:hover { transform: translateY(-3px); box-shadow: 0 16px 36px rgba(30, 41, 59, .16); }
.site-icon {
  flex: none; width: 52px; height: 52px; border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  color: #fff; background: linear-gradient(135deg, var(--accent1), var(--accent2));
}
.site-icon svg { width: 26px; height: 26px; }
.site-body { flex: 1; min-width: 0; display: flex; flex-direction: column; gap: 5px; }
.site-name { font-size: 18px; font-weight: 700; }
.site-desc { font-size: 14px; color: var(--muted); line-height: 1.5; }
.site-arrow { font-size: 22px; color: var(--muted); transition: transform .18s ease; }
.site-card:hover .site-arrow { transform: translateX(4px); color: var(--accent1); }
@media (max-width: 640px) {
  .cards { grid-template-columns: 1fr; }
  .nav-main { padding-top: 16px; }
  .brand h1 { font-size: 26px; }
}