/* V1-A 學習扶助閱讀互動平台 - 最小化樣式 */
:root{
  --primary:#2563eb;
  --primary-600:#1d4ed8;
  --bg:#f8fafc;
  --card:#ffffff;
  --border:#e2e8f0;
  --text:#0f172a;
  --muted:#64748b;
  --success:#16a34a;
  --warning:#ca8a04;
  --danger:#dc2626;
}
*{box-sizing:border-box}
body{margin:0;font-family:"Microsoft JhengHei","Noto Sans TC",system-ui,-apple-system,Segoe UI,Roboto,sans-serif;background:var(--bg);color:var(--text);line-height:1.6}
a{color:var(--primary);text-decoration:none}
header{position:sticky;top:0;z-index:20;background:#fff;border-bottom:1px solid var(--border);display:flex;align-items:center;justify-content:space-between;padding:10px 16px}
.brand{font-weight:800;letter-spacing:.02em}
.brand small{display:block;font-weight:400;color:var(--muted);font-size:12px}
.nav{display:flex;gap:8px;flex-wrap:wrap}
.btn{appearance:none;border:1px solid var(--border);background:#fff;color:var(--text);border-radius:10px;padding:8px 14px;cursor:pointer;font-size:14px}
.btn:hover{background:#f1f5f9}
.btn.primary{background:var(--primary);color:#fff;border-color:var(--primary)}
.btn.primary:hover{background:var(--primary-600)}
.btn.small{padding:6px 10px;font-size:12px}
.btn.ghost{background:transparent}
.btn:disabled{opacity:.5;cursor:not-allowed}
.badge{display:inline-block;padding:2px 8px;border-radius:999px;font-size:12px;border:1px solid var(--border);background:#fff;color:var(--muted)}
.badge.active{color:var(--success);border-color:#bbf7d0;background:#f0fdf4}
.badge.disabled{color:var(--muted);border-color:var(--border);background:#f8fafc}
.container{max-width:1080px;margin:0 auto;padding:18px 16px}
.card{background:var(--card);border:1px solid var(--border);border-radius:16px;padding:16px;box-shadow:0 1px 2px rgba(0,0,0,.04)}
.grid{display:grid;gap:16px}
.grid.cols2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid.cols3{grid-template-columns:repeat(3,minmax(0,1fr))}
@media(max-width:800px){.grid.cols2,.grid.cols3{grid-template-columns:1fr}}
.hero{text-align:center;padding:28px 12px}
.hero h1{margin:6px 0 8px;font-size:28px}
.hero p{color:var(--muted);margin:0}
.hero-actions{display:flex;gap:12px;justify-content:center;margin-top:16px;flex-wrap:wrap}
.hero-actions .btn{font-size:16px;padding:12px 18px;border-radius:12px}
.section-title{font-size:18px;font-weight:700;margin:0 0 6px}
.muted{color:var(--muted);font-size:13px}
.table{width:100%;border-collapse:collapse}
.table th,.table td{padding:8px 10px;border-bottom:1px solid var(--border);text-align:left;font-size:14px}
.table th{color:var(--muted);font-weight:600;background:#f8fafc}
.kv{display:grid;grid-template-columns:140px 1fr;gap:8px;font-size:14px}
.input, .select{width:100%;padding:8px 10px;border:1px solid var(--border);border-radius:10px;font-size:14px;background:#fff}
.input:focus,.select:focus{outline:2px solid #bfdbfe;border-color:var(--primary)}
.form-row{display:grid;gap:8px;margin:8px 0}
.form-actions{display:flex;gap:8px;justify-content:flex-end;margin-top:12px}
.modal{position:fixed;inset:0;background:rgba(15,23,42,.45);display:none;align-items:center;justify-content:center;padding:16px;z-index:30}
.modal.open{display:flex}
.modal .panel{background:#fff;border-radius:16px;max-width:560px;width:100%;padding:16px;border:1px solid var(--border);max-height:90vh;overflow:auto}
.notice{padding:10px 12px;border-radius:10px;font-size:13px;border:1px solid}
.notice.warning{background:#fffbeb;border-color:#fde68a;color:#92400e}
.notice.success{background:#f0fdf4;border-color:#bbf7d0;color:#166534}
.notice.error{background:#fef2f2;border-color:#fecaca;color:#991b1b}
.notice.info{background:#eff6ff;border-color:#bfdbfe;color:#1e40af}
.student-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(140px,1fr));gap:12px}
.student-card{border:1px solid var(--border);border-radius:14px;padding:12px;text-align:center;background:#fff;cursor:pointer}
.student-card:hover{border-color:var(--primary);box-shadow:0 4px 12px rgba(37,99,235,.12)}
.student-card .icon{font-size:28px}
.student-card .name{font-weight:700;margin:6px 0 2px}
.student-card .meta{font-size:12px;color:var(--muted)}
.class-chips{display:flex;gap:8px;flex-wrap:wrap}
.chip{padding:8px 12px;border-radius:999px;border:1px solid var(--border);background:#fff;cursor:pointer}
.chip.active{background:var(--primary);color:#fff;border-color:var(--primary)}
.toolbar{display:flex;gap:8px;align-items:center;flex-wrap:wrap;justify-content:space-between}
.sync-dot{width:8px;height:8px;border-radius:999px;display:inline-block}
.sync-dot.ok{background:var(--success)}
.sync-dot.warn{background:var(--warning)}
.sync-dot.err{background:var(--danger)}
.footer{padding:24px 16px;text-align:center;color:var(--muted);font-size:12px}
code{font-family:ui-monospace,Consolas,monospace;background:#f1f5f9;padding:1px 6px;border-radius:6px}