/* 人工智能比赛备考系统 - 样式表 */
:root {
  --bg: #f8fafc;
  --card: #ffffff;
  --border: #e2e8f0;
  --text: #1e293b;
  --text-dim: #64748b;
  --primary: #2563eb;
  --primary-light: #dbeafe;
  --success: #16a34a;
  --success-light: #dcfce7;
  --warning: #d97706;
  --warning-light: #fef3c7;
  --danger: #dc2626;
  --danger-light: #fee2e2;
  --purple: #7c3aed;
  --purple-light: #ede9fe;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { background: var(--bg); color: var(--text); font-family: "Segoe UI", "Microsoft YaHei", system-ui, sans-serif; font-size: 15px; line-height: 1.6; }

/* Header */
header { display: flex; align-items: center; gap: 20px; padding: 0 24px; height: 60px; background: var(--card); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 100; }
.logo { font-weight: 800; font-size: 18px; }
.logo b { color: var(--primary); }
.main-nav { display: flex; gap: 8px; }
.nav-link { padding: 8px 16px; border-radius: 8px; text-decoration: none; color: var(--text-dim); font-weight: 500; transition: all 0.2s; }
.nav-link:hover { background: var(--primary-light); color: var(--primary); }
.nav-link.active { background: var(--primary); color: white; }
.ml-auto { margin-left: auto; display: flex; align-items: center; gap: 12px; }
.badge { font-size: 12px; padding: 4px 12px; border-radius: 999px; }
.badge.ready { background: var(--success-light); color: var(--success); }

/* Main */
main { max-width: 1200px; margin: 0 auto; padding: 24px; }

/* Buttons */
.btn { display: inline-flex; align-items: center; gap: 6px; padding: 8px 16px; border-radius: 8px; border: 1px solid var(--border); background: var(--card); color: var(--text); font-size: 14px; font-weight: 500; cursor: pointer; transition: all 0.2s; }
.btn:hover { background: #f1f5f9; }
.btn-primary { background: var(--primary); border-color: var(--primary); color: white; }
.btn-primary:hover { background: #1d4ed8; }
.btn-success { background: var(--success); border-color: var(--success); color: white; }
.btn-danger { background: var(--danger); border-color: var(--danger); color: white; }
.btn-lg { padding: 12px 24px; font-size: 16px; }

/* Cards */
.card { background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 24px; margin-bottom: 16px; }
.card-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 16px; }
.card-title { font-size: 18px; font-weight: 700; }

/* Home Page */
.hero { text-align: center; padding: 60px 0; }
.hero h1 { font-size: 32px; font-weight: 800; margin-bottom: 12px; }
.hero p { color: var(--text-dim); font-size: 16px; margin-bottom: 32px; }
.module-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px; margin-top: 40px; }
.module-card { background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 24px; text-align: center; transition: all 0.2s; cursor: pointer; }
.module-card:hover { border-color: var(--primary); box-shadow: 0 4px 12px rgba(37, 99, 235, 0.1); }
.module-icon { font-size: 48px; margin-bottom: 12px; }
.module-title { font-size: 18px; font-weight: 700; margin-bottom: 8px; }
.module-desc { color: var(--text-dim); font-size: 14px; }
.module-meta { margin-top: 16px; display: flex; justify-content: center; gap: 16px; font-size: 13px; color: var(--text-dim); }

/* Command Training */
.command-area { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.command-prompt { background: var(--primary-light); border-radius: 12px; padding: 24px; }
.command-prompt h3 { color: var(--primary); margin-bottom: 12px; }
.command-input textarea { width: 100%; min-height: 200px; padding: 16px; border: 2px solid var(--border); border-radius: 8px; font-family: "Consolas", "Courier New", monospace; font-size: 14px; resize: vertical; }
.command-input textarea:focus { outline: none; border-color: var(--primary); }
.command-result { padding: 24px; }
.command-result.correct { background: var(--success-light); border: 2px solid var(--success); border-radius: 12px; }
.command-result.wrong { background: var(--danger-light); border: 2px solid var(--danger); border-radius: 12px; }

/* Timer */
.timer-display { font-size: 48px; font-weight: 800; font-family: "Consolas", monospace; text-align: center; padding: 20px; background: var(--card); border: 2px solid var(--border); border-radius: 12px; margin-bottom: 20px; }
.timer-display.warning { color: var(--warning); border-color: var(--warning); }
.timer-display.danger { color: var(--danger); border-color: var(--danger); animation: pulse 1s infinite; }
@keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.7; } }

/* Progress */
.progress-bar { height: 8px; background: #e2e8f0; border-radius: 4px; overflow: hidden; margin: 8px 0; }
.progress-fill { height: 100%; background: linear-gradient(90deg, var(--primary), var(--success)); transition: width 0.3s; }

/* Code Editor */
.code-editor { border: 1px solid var(--border); border-radius: 8px; overflow: hidden; }
.code-editor-header { background: #f8fafc; padding: 8px 12px; border-bottom: 1px solid var(--border); font-size: 12px; color: var(--text-dim); }
.code-editor textarea { width: 100%; min-height: 300px; padding: 16px; border: none; font-family: "Consolas", "Courier New", monospace; font-size: 14px; resize: vertical; }
.code-editor textarea:focus { outline: none; }

/* Score Display */
.score-display { text-align: center; padding: 40px; }
.score-number { font-size: 72px; font-weight: 800; color: var(--primary); }
.score-label { font-size: 18px; color: var(--text-dim); margin-top: 8px; }

/* Stats Grid */
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin: 20px 0; }
.stat-card { background: var(--card); border: 1px solid var(--border); border-radius: 8px; padding: 16px; text-align: center; }
.stat-value { font-size: 24px; font-weight: 700; }
.stat-label { font-size: 12px; color: var(--text-dim); margin-top: 4px; }

/* Wrong Answer Book */
.mistake-list { list-style: none; }
.mistake-item { padding: 16px; border: 1px solid var(--border); border-radius: 8px; margin-bottom: 8px; }
.mistake-item .question { font-weight: 500; margin-bottom: 8px; }
.mistake-item .answer { color: var(--text-dim); font-size: 14px; }
.mistake-item .your-answer { color: var(--danger); }
.mistake-item .correct-answer { color: var(--success); }

/* Responsive */
@media (max-width: 768px) {
  header { flex-wrap: wrap; }
  .main-nav { order: 3; width: 100%; overflow-x: auto; }
  .command-area { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
}