:root {
  --bg: #f5f7fa;
  --card: #ffffff;
  --border: #e2e8f0;
  --text: #1e293b;
  --muted: #64748b;
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --danger: #dc2626;
  --success: #16a34a;
  --radius: 10px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

.container { max-width: 720px; margin: 0 auto; padding: 24px 16px; }
.container.wide { max-width: 960px; }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.06);
}

h1 { font-size: 1.5rem; margin: 0 0 4px; }
h2 { font-size: 1.15rem; margin: 24px 0 12px; }
.subtitle { color: var(--muted); margin: 0 0 20px; }

label { display: block; font-weight: 600; margin: 14px 0 6px; }

input[type="text"],
input[type="password"],
input[type="email"] {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 1rem;
}
input:focus { outline: 2px solid var(--primary); border-color: transparent; }

button.btn {
  margin-top: 18px;
  width: 100%;
  padding: 11px 14px;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
}
button.btn:hover { background: var(--primary-dark); }
button.btn:disabled { opacity: 0.6; cursor: not-allowed; }

button.link-btn {
  background: none;
  border: none;
  color: var(--danger);
  cursor: pointer;
  font-size: 0.9rem;
  padding: 2px 0;
}
button.link-btn:hover { text-decoration: underline; }

.alert {
  padding: 10px 14px;
  border-radius: 8px;
  margin-top: 14px;
  font-size: 0.95rem;
  display: none;
}
.alert.show { display: block; }
.alert.error { background: #fef2f2; color: var(--danger); border: 1px solid #fecaca; }
.alert.success { background: #f0fdf4; color: var(--success); border: 1px solid #bbf7d0; }

.topbar {
  background: var(--card);
  border-bottom: 1px solid var(--border);
  padding: 12px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.topbar .brand { font-weight: 700; font-size: 1.05rem; }
.topbar nav { display: flex; gap: 16px; align-items: center; color: var(--muted); font-size: 0.92rem; }

table { width: 100%; border-collapse: collapse; margin-top: 8px; }
th, td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--border); font-size: 0.95rem; }
th { color: var(--muted); font-weight: 600; }

.badge {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 600;
}
.badge.admin { background: #eff6ff; color: var(--primary); }
.badge.member { background: #f1f5f9; color: var(--muted); }

.stat-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 8px; }
.stat { background: var(--bg); border: 1px solid var(--border); border-radius: 8px; padding: 12px 14px; }
.stat .k { color: var(--muted); font-size: 0.82rem; text-transform: uppercase; letter-spacing: 0.03em; }
.stat .v { font-weight: 600; margin-top: 2px; }

.muted { color: var(--muted); }
.right { text-align: right; }