/* =========================================================
   班主任工作台 - 全局样式（模块化后独立成文件）
   ========================================================= */
:root {
  --primary: #4f46e5;
  --primary-dark: #4338ca;
  --success: #22c55e;
  --warning: #f59e0b;
  --danger: #ef4444;
  --info: #06b6d4;
  --bg: #f8fafc;
  --card-bg: #ffffff;
  --text: #1e293b;
  --muted: #64748b;
  --border: #e2e8f0;
  --shadow: 0 4px 20px rgba(0,0,0,0.08);
  --radius: 16px;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Microsoft YaHei", sans-serif;
  background: var(--bg); color: var(--text); line-height: 1.5;
}
a { text-decoration: none; color: inherit; }
.container { max-width: 1400px; margin: 0 auto; padding: 24px; }

header {
  background: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
  color: #fff; padding: 24px 0; box-shadow: var(--shadow);
}
header .container { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 12px; }
header h1 { font-size: 22px; display: flex; align-items: center; gap: 10px; }
header .meta { font-size: 14px; opacity: 0.9; margin-top: 4px; }
header .actions { display: flex; gap: 12px; flex-wrap: wrap; }

.btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 8px 16px; border-radius: 8px; border: none; font-size: 14px;
  cursor: pointer; transition: transform .15s ease, box-shadow .15s ease, filter .15s ease, background .2s ease;
  background: #e2e8f0; color: var(--text);
}
.btn:hover { transform: translateY(-1px); filter: brightness(1.05); box-shadow: 0 4px 12px rgba(15,23,42,.14); }
.btn:active { transform: translateY(0) scale(.97); filter: brightness(.95); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none; box-shadow: none; filter: none; }
.btn-light { background: rgba(255,255,255,0.15); color: #fff; }
.btn-light:hover { background: rgba(255,255,255,0.25); }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-success { background: var(--success); color: #fff; }
.btn-success:hover { opacity: 0.9; }
.btn-danger { background: var(--danger); color: #fff; }
.btn-danger:hover { filter: brightness(1.06); }
.btn-warn { background: #f59e0b; color: #fff; }
.btn-warn:hover { filter: brightness(1.06); }
.btn-info { background: #0ea5e9; color: #fff; }
.btn-info:hover { filter: brightness(1.06); }
.btn-outline { background: #fff; color: var(--primary); border: 1px solid var(--border); }
.btn-outline:hover { background: #f1f5f9; }
.btn-sm { padding: 6px 12px; font-size: 13px; }

.toolbar { display: flex; align-items: center; justify-content: space-between; margin: 24px 0 16px; flex-wrap: wrap; gap: 10px; }
.toolbar h2 { font-size: 18px; }
.filter-bar { display: flex; gap: 10px; flex-wrap: wrap; }
.filter-bar input, .filter-bar select { padding: 8px 12px; border-radius: 8px; border: 1px solid var(--border); font-size: 14px; background: #fff; }

.cards-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 20px; }
.class-card {
  background: var(--card-bg); border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 20px; display: flex; flex-direction: column; gap: 14px;
  transition: transform 0.2s, box-shadow 0.2s;
}
.class-card:hover { transform: translateY(-4px); box-shadow: 0 12px 30px rgba(0,0,0,0.12); }
.card-header { display: flex; align-items: flex-start; justify-content: space-between; gap: 8px; }
.class-title { font-size: 18px; font-weight: 700; word-break: break-all; }
.class-grade { font-size: 13px; color: var(--muted); margin-top: 2px; }
.badge { font-size: 12px; padding: 3px 8px; border-radius: 20px; background: #eef2ff; color: var(--primary); font-weight: 600; white-space: nowrap; }
.metrics { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; }
.metric { background: #f8fafc; border-radius: 10px; padding: 12px; text-align: center; }
.metric .value { font-size: 20px; font-weight: 700; color: var(--primary); }
.metric .label { font-size: 12px; color: var(--muted); margin-top: 2px; }
.latest-exam { font-size: 13px; color: var(--muted); background: #f1f5f9; padding: 8px 12px; border-radius: 8px; word-break: break-all; }
.latest-exam strong { color: var(--text); }
.card-actions { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; margin-top: auto; }
.card-actions .btn { justify-content: center; width: 100%; }

.empty { text-align: center; padding: 60px 20px; color: var(--muted); }
.empty i { font-size: 48px; margin-bottom: 12px; opacity: 0.5; }
.step-chip {
  display: inline-flex; align-items: center; gap: 6px; background: #eef2ff; color: #4338ca;
  border: 1px solid #c7d2fe; border-radius: 999px; padding: 6px 14px; font-size: 13px; font-weight: 600;
}
.step-chip b { color: #6366f1; }

/* 骨架屏 */
.skeleton {
  height: 300px; border-radius: var(--radius);
  background: linear-gradient(90deg, #eef2f7 25%, #e2e8f0 37%, #eef2f7 63%);
  background-size: 400% 100%; animation: shimmer 1.4s infinite;
}
@keyframes shimmer { 0% { background-position: 100% 0; } 100% { background-position: -100% 0; } }

/* 顶部加载条 */
.loading-bar {
  position: fixed; top: 0; left: 0; height: 3px; width: 0; background: var(--primary);
  z-index: 1200; transition: width 0.3s, opacity 0.3s; opacity: 0; pointer-events: none;
}
.loading-bar.show { opacity: 1; width: 60%; }
.loading-bar.done { width: 100%; opacity: 0; }

/* Modal */
.modal-overlay {
  position: fixed; inset: 0; background: rgba(15,23,42,0.5); display: none;
  align-items: center; justify-content: center; z-index: 1000; padding: 20px;
}
.modal-overlay.active { display: flex; }
.modal {
  background: #fff; border-radius: var(--radius); width: 100%; max-width: 900px;
  max-height: 90vh; overflow: hidden; display: flex; flex-direction: column; box-shadow: 0 20px 50px rgba(0,0,0,0.2);
}
.modal-header { padding: 16px 20px; border-bottom: 1px solid var(--border); display: flex; align-items: center; justify-content: space-between; }
.modal-title { font-size: 18px; font-weight: 700; }
.modal-close { background: none; border: none; font-size: 22px; color: var(--muted); cursor: pointer; }
.modal-body { padding: 20px; overflow-y: auto; flex: 1; }
.form-row { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 16px; align-items: center; }
.form-row label { font-size: 14px; color: var(--muted); }
.form-row input, .form-row select { padding: 8px 12px; border: 1px solid var(--border); border-radius: 8px; font-size: 14px; background: #fff; }

table { width: 100%; border-collapse: collapse; font-size: 14px; }
th, td { padding: 10px 12px; border-bottom: 1px solid var(--border); text-align: left; white-space: nowrap; }
th { background: #f8fafc; font-weight: 600; color: var(--muted); font-size: 13px; }
tr:hover { background: #f8fafc; }
.score-input { width: 80px; padding: 6px; border: 1px solid var(--border); border-radius: 6px; text-align: right; }

.stats-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 14px; margin-bottom: 20px; }
.stat-box { background: #f8fafc; border-radius: 10px; padding: 14px; }
.stat-box .num { font-size: 22px; font-weight: 700; color: var(--primary); }
.stat-box .txt { font-size: 12px; color: var(--muted); }

.layer-bar { display: flex; height: 24px; border-radius: 12px; overflow: hidden; margin: 10px 0; }
.layer-bar span { display: flex; align-items: center; justify-content: center; font-size: 11px; color: #fff; font-weight: 600; }
.layer-A { background: var(--success); }
.layer-B { background: var(--info); }
.layer-C { background: var(--warning); }
.layer-D { background: var(--danger); }

/* 分页器 */
.pager { display: flex; align-items: center; gap: 6px; margin-top: 14px; flex-wrap: wrap; }
.pager button {
  min-width: 32px; height: 32px; padding: 0 8px; border: 1px solid var(--border);
  border-radius: 8px; background: #fff; color: var(--text); font-size: 13px; cursor: pointer;
}
.pager button.active { background: var(--primary); color: #fff; border-color: var(--primary); }
.pager button:disabled { opacity: 0.4; cursor: not-allowed; }
.pager .pager-info { font-size: 13px; color: var(--muted); margin-left: 6px; }

/* Toast */
.toast { position: fixed; bottom: 24px; right: 24px; background: #1e293b; color: #fff; padding: 12px 18px; border-radius: 10px; box-shadow: var(--shadow); display: none; z-index: 1100; max-width: 80vw; }
.toast.show { display: block; }

/* ====== 学情中心 ====== */
.btn-block { grid-column: 1 / -1; }
.insight-tabs { display: flex; gap: 4px; padding: 10px 20px 0; border-bottom: 1px solid var(--border); flex-wrap: wrap; }
.itab { padding: 10px 16px; border: none; background: none; font-size: 14px; color: var(--muted); cursor: pointer; border-bottom: 2px solid transparent; display: inline-flex; align-items: center; gap: 6px; }
.itab:hover { color: var(--text); }
.itab.active { color: var(--primary); border-bottom-color: var(--primary); font-weight: 600; }
.itab-panel { min-height: 200px; }
.chart-box { background: #f8fafc; border-radius: 12px; padding: 14px; margin: 12px 0; }
.chart-box h4 { margin: 0 0 10px; font-size: 14px; color: var(--muted); }
.chart-wrap { position: relative; height: 260px; }
.grade-tag { display: inline-block; width: 22px; height: 22px; line-height: 22px; text-align: center; border-radius: 6px; font-size: 12px; font-weight: 700; color: #fff; }
.gt-A { background: var(--success); }
.gt-B { background: var(--info); }
.gt-C { background: var(--warning); }
.gt-D { background: var(--danger); }
.lv { display: inline-block; padding: 2px 10px; border-radius: 12px; font-size: 12px; font-weight: 600; }
.lv-high { background: #fee2e2; color: var(--danger); }
.lv-watch { background: #fef3c7; color: #b45309; }
.lv-normal { background: #dcfce7; color: #16a34a; }
.rate-bar { background: #e2e8f0; border-radius: 6px; height: 10px; overflow: hidden; min-width: 80px; }
.rate-bar > span { display: block; height: 100%; background: var(--primary); border-radius: 6px; }
.rate-bar.low > span { background: var(--danger); }
.rate-bar.mid > span { background: var(--warning); }
.trend-up { color: var(--success); font-weight: 600; }
.trend-down { color: var(--danger); font-weight: 600; }
.kp-row { display: flex; align-items: center; gap: 10px; margin-bottom: 10px; }
.kp-row .kp-name { width: 160px; font-size: 13px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.kp-row .rate-bar { flex: 1; }
.kp-row .kp-val { width: 120px; font-size: 12px; color: var(--muted); text-align: right; }

/* ====== 移动端优化 ====== */
@media (max-width: 640px) {
  .container { padding: 16px; }
  header { padding: 16px 0; }
  header h1 { font-size: 18px; }
  .cards-grid { grid-template-columns: 1fr; }
  .card-actions { grid-template-columns: 1fr 1fr; }
  .modal { max-width: 100%; }
  .modal-body { padding: 14px; }
  .form-row input, .form-row select { min-width: 0; }
  table { font-size: 13px; }
  th, td { padding: 8px 8px; }
  .insight-tabs { overflow-x: auto; flex-wrap: nowrap; -webkit-overflow-scrolling: touch; }
  .itab { white-space: nowrap; }
  .chart-wrap { height: 220px; }
}
@media (min-width: 641px) and (max-width: 1024px) {
  .cards-grid { grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); }
}

/* ====== AI 助手 ====== */
.ai-ask-row { display: flex; gap: 8px; margin-bottom: 10px; }
.ai-ask-row input { flex: 1; padding: 9px 12px; border: 1px solid var(--border); border-radius: 8px; font-size: 13px; }
.ai-ask-row input:focus { outline: none; border-color: var(--primary); }
.ai-actions { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 12px; }
.ai-result { background: #f8fafc; border: 1px solid var(--border); border-radius: 10px; padding: 14px; min-height: 120px; }
.ai-text { font-size: 13.5px; line-height: 1.9; color: var(--text); white-space: normal; word-break: break-word; margin-top: 8px; }
.ai-src { display: inline-block; font-size: 11px; font-weight: 600; padding: 2px 8px; border-radius: 20px; }
.ai-src-ai { background: #eef2ff; color: var(--primary); }
.ai-src-local { background: #f3e8ff; color: #7c3aed; }