:root{--color-present:#10b981;--color-absent:#ef4444;--color-bg:#f8fafc;--color-surface:#fff;--color-text:#0f172a;--color-muted:#64748b;--color-border:#e2e8f0;--color-primary:#2563eb;--color-warning:#fbbf24;--shadow-sm:0 1px 2px rgba(0,0,0,.06);--shadow-md:0 4px 12px rgba(0,0,0,.08);--radius:12px}*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}body,html{margin:0;padding:0}body{font-family:-apple-system,BlinkMacSystemFont,Pretendard,Apple SD Gothic Neo,sans-serif;background:var(--color-bg);color:var(--color-text);font-size:16px;line-height:1.4;-webkit-font-smoothing:antialiased;overscroll-behavior-y:contain}button{font-family:inherit;font-size:inherit;cursor:pointer;border:none;background:none}a,button{color:inherit}a{text-decoration:none}.grade-picker-wrap{min-height:100vh;padding:40px 20px 48px;display:flex;flex-direction:column;align-items:center}.grade-picker-title{font-size:26px;font-weight:700;margin-bottom:6px}.grade-picker-sub{color:var(--color-muted);margin-bottom:32px;font-size:15px}.grade-picker-grid{display:grid;grid-template-columns:repeat(3,1fr);grid-gap:16px;gap:16px;width:100%;max-width:480px}.grade-card{background:var(--color-surface);border:2px solid var(--color-border);border-radius:var(--radius);padding:32px 12px;text-align:center;box-shadow:var(--shadow-sm);transition:transform .08s,border-color .15s,background .15s;cursor:pointer}.grade-card:active{transform:scale(.96)}.grade-card:hover{border-color:var(--color-primary);background:#eff6ff}.grade-card-num{font-size:36px;font-weight:700;color:var(--color-primary)}.grade-card-label{font-size:14px;color:var(--color-muted);margin-top:4px}.picker-wrap{min-height:100vh;padding:32px 20px 40px;display:flex;flex-direction:column;align-items:center}.picker-back{align-self:flex-start;color:var(--color-primary);font-size:14px;margin-bottom:16px;cursor:pointer}.picker-title{font-size:24px;font-weight:700;margin-bottom:6px}.picker-sub{color:var(--color-muted);margin-bottom:28px;font-size:14px}.picker-grid{display:grid;grid-template-columns:repeat(3,1fr);grid-gap:12px;gap:12px;width:100%;max-width:480px}.picker-card{background:var(--color-surface);border:2px solid var(--color-border);border-radius:var(--radius);padding:24px 12px;text-align:center;box-shadow:var(--shadow-sm);transition:transform .08s,border-color .15s,background .15s}.picker-card:active{transform:scale(.97)}.picker-card:hover{border-color:var(--color-primary);background:#eff6ff}.picker-num{font-size:32px;font-weight:700;color:var(--color-primary)}.picker-label{font-size:13px;color:var(--color-muted);margin-top:2px}.class-tabs{display:flex;gap:2px;overflow-x:auto;-webkit-overflow-scrolling:touch;background:var(--color-surface);border-bottom:1px solid var(--color-border);padding:6px 8px;position:-webkit-sticky;position:sticky;top:0;z-index:11}.class-tab{flex:1 0 auto;min-width:48px;padding:8px 10px;border-radius:8px;text-align:center;font-size:13px;font-weight:600;color:var(--color-muted);background:transparent;cursor:pointer;white-space:nowrap}.class-tab.active{background:var(--color-primary);color:#fff}.class-tab:not(.active):hover{background:var(--color-bg)}.teacher-class-tabs{padding:8px}.header{position:-webkit-sticky;position:sticky;top:53px;z-index:10;background:var(--color-surface);border-bottom:1px solid var(--color-border);padding:12px 16px;display:flex;align-items:center;gap:12px}.header-class{font-size:14px;font-weight:700;color:var(--color-primary);background:#eff6ff;padding:4px 10px;border-radius:6px;white-space:nowrap}.header-date{font-size:14px;color:var(--color-muted);min-width:96px}.period-toggle{flex:1 1;display:flex;gap:6px;background:var(--color-bg);padding:4px;border-radius:10px}.period-btn{flex:1 1;min-height:40px;border-radius:8px;font-weight:600;color:var(--color-muted);transition:all .15s}.period-btn.active{background:var(--color-surface);color:var(--color-text);box-shadow:var(--shadow-sm)}.refresh-btn{width:40px;height:40px;border-radius:8px;display:flex;align-items:center;justify-content:center;color:var(--color-muted)}.refresh-btn:active{background:var(--color-bg)}.banner{background:var(--color-warning);color:#78350f;padding:10px 16px;font-size:14px;text-align:center}.new-feature-card{display:block;font-size:12px;color:var(--color-primary);background:#eff6ff;border-bottom:1px solid #bfdbfe;padding:7px 12px;line-height:1.5;text-align:center;pointer-events:none}.grid{display:grid;grid-gap:10px;gap:10px;padding:12px;grid-template-columns:repeat(2,1fr)}@media (min-width:600px){.grid{grid-template-columns:repeat(3,1fr)}}@media (min-width:900px){.grid{grid-template-columns:repeat(4,1fr)}}@media (min-width:1200px){.grid{grid-template-columns:repeat(5,1fr)}}.card{background:var(--color-surface);border-radius:var(--radius);padding:14px 12px;min-height:96px;display:flex;flex-direction:column;justify-content:space-between;box-shadow:var(--shadow-sm);border:2px solid transparent;transition:transform .08s,border-color .15s;-webkit-user-select:none;-moz-user-select:none;user-select:none;cursor:pointer;position:relative}.card:active{transform:scale(.97)}.card.absent{border-color:var(--color-absent);background:#fef2f2}.card.present{border-color:var(--color-present);background:#ecfdf5}.card-name{font-size:17px;font-weight:700}.card-id{font-size:12px;color:var(--color-muted);margin-top:2px}.card-status{margin-top:8px;font-size:13px;font-weight:600;display:inline-flex;align-items:center;gap:4px}.card.absent .card-status{color:var(--color-absent)}.card.present .card-status{color:var(--color-present)}.card-status:before{content:"";width:8px;height:8px;border-radius:50%;background:currentColor;display:inline-block}.card-memo{position:absolute;top:6px;right:8px;font-size:11px;color:var(--color-muted);max-width:60%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.summary-bar{position:-webkit-sticky;position:sticky;bottom:0;z-index:10;background:var(--color-surface);border-top:1px solid var(--color-border);padding:14px 16px;text-align:center;font-weight:600;font-size:16px}.summary-bar .pres{color:var(--color-present)}.summary-bar .abs{color:var(--color-absent)}.toast-container{position:fixed;bottom:80px;right:16px;z-index:100;display:flex;flex-direction:column;gap:8px;pointer-events:none}.toast{background:rgba(15,23,42,.92);color:#fff;padding:10px 16px;border-radius:10px;font-size:14px;box-shadow:var(--shadow-md);animation:toast-in .2s ease}.toast.error{background:var(--color-absent)}@keyframes toast-in{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.sheet-backdrop{position:fixed;inset:0;background:rgba(0,0,0,.4);z-index:50;display:none}.sheet-backdrop.open{display:block}.bottom-sheet{position:fixed;left:0;right:0;bottom:0;z-index:60;background:var(--color-surface);border-radius:16px 16px 0 0;padding:20px 16px 24px;transform:translateY(100%);transition:transform .2s ease;box-shadow:0 -4px 16px rgba(0,0,0,.1)}.bottom-sheet.open{transform:translateY(0)}.bottom-sheet h3{margin:0 0 12px;font-size:17px}.bottom-sheet input{width:100%;padding:12px;font-size:16px;border:1px solid var(--color-border);border-radius:8px;margin-bottom:12px}.sheet-actions{display:flex;gap:8px}.sheet-actions button{flex:1 1;padding:12px;border-radius:8px;font-weight:600}.btn-secondary{background:var(--color-bg);color:var(--color-text)}.login-wrap{min-height:100vh;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:24px}.login-title{font-size:22px;font-weight:700;margin-bottom:8px}.login-sub{color:var(--color-muted);margin-bottom:32px;font-size:14px;text-align:center}.pin-input{width:240px;padding:16px;font-size:28px;text-align:center;letter-spacing:12px;border:2px solid var(--color-border);border-radius:12px;background:var(--color-surface)}.pin-input.error{border-color:var(--color-absent);animation:shake .4s}.login-msg{margin-top:12px;min-height:20px;font-size:14px;color:var(--color-absent)}@keyframes shake{0%,to{transform:translateX(0)}25%{transform:translateX(-6px)}75%{transform:translateX(6px)}}.teacher-wrap{padding-bottom:40px}.grade-tabs{display:flex;gap:2px;overflow-x:auto;-webkit-overflow-scrolling:touch;background:var(--color-surface);border-bottom:1px solid var(--color-border);padding:6px 8px;position:-webkit-sticky;position:sticky;top:0;z-index:12}.grade-tab{flex:1 0 auto;min-width:60px;padding:8px 12px;border-radius:8px;text-align:center;font-size:13px;font-weight:600;color:var(--color-muted);cursor:pointer;white-space:nowrap}.grade-tab.active{background:var(--color-primary);color:#fff}.grade-tab:not(.active):hover{background:var(--color-bg)}.tabs{display:flex;gap:4px;padding:8px;background:var(--color-surface);border-bottom:1px solid var(--color-border);position:-webkit-sticky;position:sticky;top:53px;z-index:5}.tab-btn{flex:1 1;padding:12px;border-radius:8px;font-weight:600;color:var(--color-muted)}.tab-btn.active{background:var(--color-primary);color:#fff}.tab-panel{display:none;padding:16px}.tab-panel.active{display:block}.panel-section{margin-bottom:24px}.panel-section h2{font-size:16px;margin:0 0 8px}.summary-row{font-size:14px;color:var(--color-muted);margin-bottom:12px}.period-card{background:var(--color-surface);border-radius:var(--radius);padding:14px;margin-bottom:12px;box-shadow:var(--shadow-sm)}.period-card h3{margin:0 0 8px;font-size:15px}.absent-list{list-style:none;padding:0;margin:0;display:flex;flex-direction:column;gap:6px}.absent-list li{padding:8px 10px;background:#fef2f2;border-radius:8px;font-size:14px;display:flex;justify-content:space-between;gap:8px}.absent-list .empty{background:#ecfdf5;color:var(--color-present);justify-content:center}.absent-list .memo{color:var(--color-muted);font-size:12px}table{width:100%;border-collapse:collapse;font-size:13px}td,th{padding:8px 6px;text-align:center;border-bottom:1px solid var(--color-border)}th{background:var(--color-bg);font-weight:600;cursor:pointer;-webkit-user-select:none;-moz-user-select:none;user-select:none}th.sorted:after{content:" ▾"}th.sorted.asc:after{content:" ▴"}td.name{text-align:left;font-weight:600}.matrix-wrap{overflow-x:auto;-webkit-overflow-scrolling:touch;border:1px solid var(--color-border);border-radius:8px;background:var(--color-surface)}.matrix-table{font-size:11px;min-width:100%}.matrix-table td,.matrix-table th{padding:4px 6px;min-width:32px;white-space:nowrap;border-right:1px solid var(--color-border)}.matrix-table th.day-header{writing-mode:vertical-rl;-webkit-text-orientation:upright;text-orientation:upright;letter-spacing:1px;line-height:1.1;padding:6px 2px}.matrix-table td.cell-present{color:var(--color-present);font-weight:700}.matrix-table td.cell-absent{color:var(--color-absent);font-weight:700}.matrix-table td.has-memo{background:#fef9c3}.matrix-table td.sticky-col,.matrix-table th.sticky-col{position:-webkit-sticky;position:sticky;left:0;background:var(--color-surface);z-index:1;border-right:2px solid var(--color-border)}.matrix-table th.sticky-col{background:var(--color-bg);z-index:2}.controls{display:flex;gap:8px;margin-bottom:12px;flex-wrap:wrap;align-items:center}.btn,select{padding:10px 14px;border:1px solid var(--color-border);border-radius:8px;background:var(--color-surface);font-size:14px}.btn-primary{background:var(--color-primary);color:#fff;border:none}.loading{padding:40px;text-align:center;color:var(--color-muted)}.cls-summary-row{cursor:pointer}.cls-summary-row:hover{background:#eff6ff}.participants-cell{font-weight:600;color:var(--color-primary)}.toggle-arrow{font-size:11px;color:var(--color-muted)}.cls-detail-row td{padding:10px 12px;background:#f8fafc}.participant-chips{display:flex;flex-wrap:wrap;gap:6px}.participant-chip{display:inline-flex;align-items:center;gap:4px;background:var(--color-surface);border:1px solid var(--color-border);border-radius:6px;padding:4px 8px;font-size:13px;font-weight:600}.participant-chip small{font-size:11px;font-weight:400;color:var(--color-muted)}.total-row{font-weight:700;border-top:2px solid var(--color-border)}.all-table-hint{font-size:12px;color:var(--color-muted);margin-top:8px}.cell-present-bg{background:#d1fae5}.status-badge{display:inline-block;padding:2px 6px;border-radius:4px;font-size:11px;font-weight:600;margin-left:6px}.status-badge.present{background:#d1fae5;color:var(--color-present)}.status-badge.absent{background:#fee2e2;color:var(--color-absent)}.status-badge.unexpected{background:#fef9c3;color:#a16207}.unexpected-header{font-size:13px;font-weight:600;color:#a16207;padding:4px 8px;margin-top:8px}.unexpected-list li{background:#fffbeb}.scheduled-list li.is-absent{opacity:.6}.memo-tip{font-size:11px;color:var(--color-muted);margin:0 0 8px}.absent-list li.memo-editable{cursor:context-menu;-webkit-user-select:none;-moz-user-select:none;user-select:none}.absent-list li.memo-editable .memo-hint{display:none}.absent-list li.memo-editable:hover .memo-hint{display:inline;color:var(--color-muted);font-size:11px;opacity:.5}.absent-list li.has-memo{background:#fffbeb;border-left:3px solid #fbbf24}.absent-list li.has-memo .memo-text{color:#92400e;font-size:12px;font-weight:600;display:block;margin-top:2px}.absent-list li.is-absent.has-memo{opacity:.85}.memo-modal-overlay{position:fixed;inset:0;background:rgba(0,0,0,.5);z-index:200;display:flex;align-items:center;justify-content:center;padding:16px}.memo-modal-box{background:var(--color-surface);border-radius:var(--radius);padding:20px 20px 16px;width:100%;max-width:420px;box-shadow:0 8px 32px rgba(0,0,0,.18)}.memo-modal-title{font-size:16px;font-weight:700;margin-bottom:4px}.memo-modal-hint{font-size:13px;color:var(--color-muted);margin-bottom:12px}.memo-modal-box input{width:100%;padding:12px;font-size:15px;border:1px solid var(--color-border);border-radius:8px;margin-bottom:12px;font-family:inherit;outline:none;transition:border-color .15s}.memo-modal-box input:focus{border-color:var(--color-primary)}.memo-modal-actions{display:flex;gap:8px}.memo-modal-actions button{flex:1 1;padding:12px;border-radius:8px;font-weight:600;font-size:14px}.memo-clear-btn{color:var(--color-absent);background:#fef2f2}