:root {
  --bg: #f3f7fb;
  --card: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --primary: #0ea5e9;
  --primary-hover: #0284c7;
  --border: #dbe3ea;
  --danger: #dc2626;
  --ok: #16a34a;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Noto Sans CJK SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: linear-gradient(135deg, #f0f9ff, var(--bg));
}

.page {
  min-height: 100dvh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.card {
  width: min(420px, 100%);
  background: var(--card);
  border-radius: 16px;
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.08);
  padding: 28px;
}

h1 {
  margin: 0 0 6px;
  font-size: 26px;
}

.subtitle {
  margin: 0 0 20px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.5;
}

.form {
  display: grid;
  gap: 12px;
}

.field {
  display: grid;
  gap: 6px;
  font-size: 14px;
}

.field span { color: #374151; }

input {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 11px 12px;
  font-size: 15px;
  outline: none;
}

input:focus {
  border-color: #7dd3fc;
  box-shadow: 0 0 0 3px rgba(14, 165, 233, 0.15);
}

.btn {
  margin-top: 4px;
  border: 0;
  border-radius: 10px;
  padding: 12px;
  background: var(--primary);
  color: white;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
}

.btn:hover { background: var(--primary-hover); }

.btn.secondary {
  margin-top: 10px;
  width: 100%;
  background: #16a34a;
}

.btn.secondary:hover {
  background: #15803d;
}

.msg {
  min-height: 22px;
  margin-top: 10px;
  font-size: 14px;
}

.msg.error { color: var(--danger); }
.msg.ok { color: var(--ok); }

.actions {
  margin-top: 14px;
  display: flex;
  justify-content: space-between;
}

.link {
  border: none;
  background: transparent;
  color: #0369a1;
  font-size: 14px;
  cursor: pointer;
  padding: 0;
}

.link:hover { text-decoration: underline; }

.admin-page {
  min-height: 100dvh;
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 16px;
  padding: 20px;
}

.card-like {
  background: var(--card);
  border-radius: 16px;
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.08);
  padding: 20px;
}

.admin-sidebar h2 {
  margin: 0 0 6px;
}

.admin-menu {
  display: grid;
  gap: 10px;
  margin: 14px 0 20px;
}

.menu-item {
  border: 1px solid var(--border);
  background: #fff;
  border-radius: 10px;
  padding: 10px 12px;
  text-align: left;
  cursor: pointer;
  color: #1f2937;
}

.menu-item.active {
  background: #e0f2fe;
  border-color: #7dd3fc;
  color: #075985;
  font-weight: 600;
}

.admin-content {
  min-height: 420px;
}

.panel {
  display: none;
}

.panel.active {
  display: block;
}

@media (max-width: 900px) {
  .admin-page {
    grid-template-columns: 1fr;
  }
}