:root{--primary: #2563eb;--primary-dark: #1e40af;--primary-soft: #dbeafe;--cyan: #06b6d4;--green: #16a34a;--red: #dc2626;--orange: #f59e0b;--text: #334155;--text-dark: #0f172a;--text-muted: #64748b;--bg: #f5f7fb;--card: #ffffff;--border: #e5e7eb;--input-border: #dbe3ef;--shadow: 0 18px 45px rgba(15, 23, 42, .08);font-family:Inter,Arial,system-ui,sans-serif;color:var(--text);background:var(--bg);font-synthesis:none;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}*{box-sizing:border-box}body{margin:0;background:var(--bg)}button,input,select,textarea{font-family:inherit}#app{width:100%;max-width:100%;min-height:100vh;box-sizing:border-box}.teacher-page{min-height:100vh;padding:28px;background:radial-gradient(circle at top left,rgba(37,99,235,.16),transparent 34%),radial-gradient(circle at top right,rgba(6,182,212,.16),transparent 34%),linear-gradient(135deg,#eef2ff,#f8fafc 45%,#ecfeff);color:var(--text-dark)}.teacher-wrap{max-width:1180px;margin:0 auto}.teacher-hero{background:linear-gradient(135deg,#1e3a8a,#2563eb,#06b6d4);color:#fff;border-radius:28px;padding:28px;box-shadow:0 22px 50px #2563eb38;display:flex;justify-content:space-between;align-items:center;gap:18px;margin-bottom:22px}.teacher-hero-left{display:flex;align-items:center;gap:18px}.teacher-hero h1{margin:0;font-size:30px;letter-spacing:-.5px;color:#fff}.teacher-hero p{margin:8px 0 0;color:#dbeafe;line-height:1.5}.teacher-avatar{width:72px;height:72px;border-radius:24px;background:#ffffff2e;border:1px solid rgba(255,255,255,.35);display:grid;place-items:center;font-size:34px;-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);flex-shrink:0}.logout-modern{padding:11px 16px;background:#ffffff29;color:#fff;border:1px solid rgba(255,255,255,.32);border-radius:14px;cursor:pointer;font-weight:700;transition:all .2s ease}.logout-modern:hover{background:#ffffff3d;transform:translateY(-1px)}.teacher-grid{display:grid;grid-template-columns:340px 1fr;gap:22px;align-items:start}.modern-card{background:#ffffffe0;border:1px solid rgba(226,232,240,.9);border-radius:24px;box-shadow:var(--shadow);-webkit-backdrop-filter:blur(14px);backdrop-filter:blur(14px);overflow:hidden}.modern-card-body{padding:22px}.card-title{margin:0;font-size:20px;color:var(--text-dark);letter-spacing:-.2px;font-weight:800}.card-subtitle{margin:6px 0 18px;color:var(--text-muted);font-size:14px;line-height:1.5}.profile-top{text-align:center;padding:24px 20px;background:linear-gradient(135deg,#eff6ff,#ecfeff);border-bottom:1px solid #e2e8f0}.profile-icon{width:82px;height:82px;border-radius:28px;background:linear-gradient(135deg,#2563eb,#06b6d4);color:#fff;display:grid;place-items:center;margin:0 auto 12px;font-size:36px;box-shadow:0 15px 30px #2563eb40}.profile-name{font-weight:800;font-size:19px;margin-bottom:4px;color:var(--text-dark)}.profile-id{color:var(--text-muted);font-size:13px}.info-row{display:flex;justify-content:space-between;gap:16px;padding:13px 0;border-bottom:1px solid #f1f5f9}.info-row:last-child{border-bottom:none}.info-label{color:var(--text-muted);font-size:13px}.info-value{font-weight:700;text-align:right;color:var(--text-dark);max-width:180px;word-break:break-word}.badge-soft{display:inline-flex;align-items:center;gap:6px;padding:7px 11px;border-radius:999px;background:var(--primary-soft);color:#1d4ed8;font-size:12px;font-weight:800}.form-grid-modern{display:grid;grid-template-columns:repeat(2,minmax(240px,1fr));gap:16px}.field-full{grid-column:1 / -1}.modern-label{display:block;margin-bottom:7px;font-size:13px;color:#334155;font-weight:800}.modern-input,.modern-select,.modern-textarea{width:100%;padding:13px 14px;border:1px solid var(--input-border);border-radius:15px;background:#fff;color:var(--text-dark);outline:none;transition:all .2s ease;font-size:14px}.modern-input:focus,.modern-select:focus,.modern-textarea:focus{border-color:var(--primary);box-shadow:0 0 0 4px #2563eb1f}.modern-input[readonly]{background:#f8fafc;color:#475569}.modern-textarea{resize:vertical;min-height:110px}.btn-primary-modern{padding:13px 18px;border:none;border-radius:15px;background:linear-gradient(135deg,#2563eb,#06b6d4);color:#fff;cursor:pointer;font-weight:800;box-shadow:0 12px 24px #2563eb38;transition:all .2s ease}.btn-primary-modern:hover{transform:translateY(-1px);box-shadow:0 16px 28px #2563eb47}.btn-primary-modern:disabled{opacity:.65;cursor:not-allowed;transform:none}.btn-secondary-modern{padding:13px 18px;border:none;border-radius:15px;background:#e2e8f0;color:var(--text-dark);cursor:pointer;font-weight:800;transition:all .2s ease}.btn-secondary-modern:hover{background:#cbd5e1}.student-dropdown{display:none;position:absolute;z-index:20;left:0;right:0;top:78px;background:#fff;border:1px solid #e5e7eb;border-radius:18px;box-shadow:0 18px 40px #0f172a29;overflow:hidden}.student-option-modern,.student-option{width:100%;text-align:left;border:none;background:#fff;padding:14px;cursor:pointer;border-bottom:1px solid #f1f5f9;transition:all .15s ease}.student-option-modern:hover,.student-option:hover{background:#eff6ff}.history-box{margin-top:24px;padding-top:22px;border-top:1px solid #e5e7eb}.history-filter{display:grid;grid-template-columns:repeat(5,minmax(130px,1fr));gap:12px;margin-bottom:14px}.history-table-wrap{overflow:auto;border:1px solid #e5e7eb;border-radius:18px;background:#fff}.history-table{width:100%;border-collapse:collapse;min-width:920px}.history-table th{padding:13px;text-align:left;background:#f8fafc;color:#475569;font-size:13px;border-bottom:1px solid #e5e7eb;white-space:nowrap}.history-table td{padding:13px;border-bottom:1px solid #f1f5f9;vertical-align:top;font-size:14px}.status-badge{display:inline-flex;padding:6px 10px;border-radius:999px;font-size:12px;font-weight:800}.alert-success{padding:12px;background:#dcfce7;color:#166534;border-radius:12px;font-weight:800}.alert-danger{padding:12px;background:#fee2e2;color:#991b1b;border-radius:12px;font-weight:800}.empty-state{padding:18px;background:#f8fafc;border:1px dashed #cbd5e1;border-radius:12px;text-align:center;color:var(--text-muted)}@media (max-width: 900px){.teacher-page{padding:18px}.teacher-grid,.form-grid-modern,.history-filter{grid-template-columns:1fr}.teacher-hero{flex-direction:column;align-items:flex-start}.teacher-hero-left{align-items:flex-start}.teacher-hero h1{font-size:25px}.teacher-avatar{width:60px;height:60px;border-radius:20px;font-size:28px}}@media (max-width: 520px){.teacher-page{padding:12px}.teacher-hero{padding:20px;border-radius:22px}.teacher-hero-left{flex-direction:column}.modern-card{border-radius:20px}.modern-card-body{padding:18px}}:root{--primary:#2563eb;--accent:#0ea5e9;--bg:#f1f5f9;--card:#ffffff;--line:#e2e8f0;--text:#0f172a;--muted:#64748b;--radius:16px;--shadow:0 10px 30px rgba(2,6,23,.08);--shadow-sm:0 4px 14px rgba(2,6,23,.06)}body{background:linear-gradient(180deg,#f8fafc,#eef2f7) fixed;color:var(--text);font-family:Segoe UI,system-ui,-apple-system,Helvetica Neue,Arial,sans-serif}*{-webkit-font-smoothing:antialiased}.modern-card,.modern-card-body{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow-sm);transition:box-shadow .25s ease}.modern-card-body{padding:20px 22px}.modern-card:hover{box-shadow:var(--shadow)}.teacher-hero{background:linear-gradient(135deg,#1e3a8a,#2563eb 55%,#0ea5e9);border-radius:20px;color:#fff;padding:26px 28px;box-shadow:0 16px 40px #2563eb59;display:flex;justify-content:space-between;align-items:center;gap:16px;flex-wrap:wrap}.teacher-hero h1{margin:0;font-size:26px;letter-spacing:.3px}.teacher-hero p{margin:6px 0 0;opacity:.85;font-size:13.5px}.teacher-avatar{width:64px;height:64px;border-radius:18px;background:#ffffff2e;display:flex;align-items:center;justify-content:center;font-size:32px;border:1px solid rgba(255,255,255,.25);-webkit-backdrop-filter:blur(6px);backdrop-filter:blur(6px)}.logout-modern{background:#ffffff29;color:#fff;border:1px solid rgba(255,255,255,.35);border-radius:12px;padding:10px 18px;font-weight:600;cursor:pointer;transition:.2s}.logout-modern:hover{background:#dc2626;border-color:#dc2626}.teacherTabBtn{border:none;cursor:pointer;padding:10px 18px;border-radius:999px;font-weight:600;font-size:13.5px;transition:.2s;letter-spacing:.2px}.btn-primary-modern{background:linear-gradient(135deg,var(--primary),var(--accent));color:#fff;box-shadow:0 6px 16px #2563eb59}.btn-primary-modern:hover{transform:translateY(-1px);box-shadow:0 10px 22px #2563eb73}.btn-secondary-modern{background:#eef2f7;color:#334155}.btn-secondary-modern:hover{background:#e2e8f0;transform:translateY(-1px)}.card-title{font-size:20px;font-weight:700;margin:0 0 4px;color:var(--text)}.card-subtitle{color:var(--muted);font-size:13px;margin:0 0 18px}.modern-input,.modern-select,.modern-textarea{width:100%;padding:11px 14px;border:1.5px solid var(--line);border-radius:12px;font-size:14px;background:#fbfdff;outline:none;transition:border .2s,box-shadow .2s}.modern-input:focus,.modern-select:focus,.modern-textarea:focus{border-color:var(--primary);box-shadow:0 0 0 4px #2563eb1f;background:#fff}.modern-label{font-size:12px;font-weight:700;color:#334155;margin-bottom:6px;display:block}.history-table-wrap{border:1px solid var(--line);border-radius:14px;overflow:auto;background:#fff;box-shadow:var(--shadow-sm)}.history-table{width:100%;border-collapse:separate;border-spacing:0;font-size:13.5px}.history-table thead th{background:linear-gradient(135deg,#0f172a,#1e293b);color:#e2e8f0;font-size:12px;text-transform:uppercase;letter-spacing:.6px;padding:12px 14px;text-align:left;position:sticky;top:0;z-index:2}.history-table tbody td{padding:11px 14px;border-bottom:1px solid #eef2f7}.history-table tbody tr:nth-child(2n){background:#f8fafc}.history-table tbody tr:hover{background:#eff6ff}.history-table tbody tr:last-child td{border-bottom:none}.status-badge{padding:4px 12px;border-radius:999px;font-size:11.5px;font-weight:700;letter-spacing:.3px}.status-success{background:#dcfce7;color:#166534}.status-danger{background:#fee2e2;color:#991b1b}.alert-success{background:#f0fdf4;border:1px solid #bbf7d0;color:#166534;padding:12px 16px;border-radius:12px;font-weight:600}.alert-danger{background:#fef2f2;border:1px solid #fecaca;color:#991b1b;padding:12px 16px;border-radius:12px;font-weight:600}.empty-state{padding:28px;text-align:center;color:var(--muted);background:#f8fafc;border:1px dashed var(--line);border-radius:14px}.history-filter{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:12px}.history-filter .modern-card-body{text-align:center;font-size:13px}.student-dropdown{border:1px solid var(--line);border-radius:12px;overflow:hidden;box-shadow:var(--shadow)}.student-option-modern{width:100%;text-align:left;background:#fff;border:none;padding:10px 14px;cursor:pointer}.student-option-modern:hover{background:#eff6ff}::-webkit-scrollbar{width:10px;height:10px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:#cbd5e1;border-radius:999px;border:2px solid #f1f5f9}::-webkit-scrollbar-thumb:hover{background:#94a3b8}