/* English Exam System - 共用樣式 */
:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --bg: #f8fafc;
  --card: #fff;
  --text: #1e293b;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --success: #16a34a;
  --danger: #dc2626;
}
* { box-sizing: border-box; }
body { font-family: 'Segoe UI', system-ui, sans-serif; margin: 0; background: var(--bg); color: var(--text); line-height: 1.6; }
.container { max-width: 960px; margin: 0 auto; padding: 1rem 1.5rem; }
.card { background: var(--card); border-radius: 12px; box-shadow: 0 1px 3px rgba(0,0,0,.08); padding: 1.5rem; margin-bottom: 1rem; }
.btn { display: inline-block; padding: 0.6rem 1.2rem; border-radius: 8px; border: none; cursor: pointer; font-size: 1rem; text-decoration: none; transition: background .2s; }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-secondary { background: var(--border); color: var(--text); }
.btn-danger { background: var(--danger); color: #fff; }
input[type="text"], input[type="email"], input[type="password"], input[type="number"], textarea, select {
  width: 100%; padding: 0.6rem .75rem; border: 1px solid var(--border); border-radius: 8px; font-size: 1rem;
}
label { display: block; margin-bottom: 0.25rem; font-weight: 500; }
.form-group { margin-bottom: 1rem; }
nav { background: var(--card); border-bottom: 1px solid var(--border); padding: 0.75rem 1.5rem; }
nav a { margin-right: 1rem; color: var(--primary); text-decoration: none; }
nav a:hover { text-decoration: underline; }
.alert { padding: 0.75rem 1rem; border-radius: 8px; margin-bottom: 1rem; }
.alert-error { background: #fef2f2; color: var(--danger); }
.alert-success { background: #f0fdf4; color: var(--success); }
.text-center { text-align: center; }
.mt-2 { margin-top: 1rem; }
h1, h2 { margin-top: 0; }