:root{color-scheme:dark;font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;line-height:1.5;--green: #22c55e;--yellow: #eab308;--red: #ef4444;--bg: #0a0a0a;--surface: #141414;--border: rgba(255, 255, 255, .1);--muted: rgba(255, 255, 255, .55)}*{box-sizing:border-box;margin:0}html,body,#root{min-height:100vh;background:var(--bg);color:#fafafa}.app{max-width:52rem;margin:0 auto;padding:1.5rem}.header{margin-bottom:1.5rem}.header h1{font-size:1.6rem;font-weight:700;letter-spacing:-.03em;margin-bottom:1rem}.nav-tabs{display:flex;gap:.25rem;border-bottom:1px solid var(--border)}.tab{background:none;border:none;color:var(--muted);padding:.5rem 1rem;cursor:pointer;font-size:.9rem;border-bottom:2px solid transparent;transition:color .15s,border-color .15s}.tab:hover{color:#fff}.tab.active{color:#fff;border-bottom-color:var(--green)}.add-student{margin-bottom:1.5rem}.add-student form{display:flex;gap:.5rem}.add-student input{flex:1;background:var(--surface);border:1px solid var(--border);color:#fff;padding:.55rem .75rem;border-radius:.5rem;font-size:.9rem;outline:none;transition:border-color .15s}.add-student input:focus{border-color:#ffffff40}.add-student button{background:var(--green);color:#000;border:none;padding:.55rem 1rem;border-radius:.5rem;font-weight:600;font-size:.9rem;cursor:pointer;transition:opacity .15s}.add-student button:hover{opacity:.85}.date-bar{display:flex;align-items:center;justify-content:space-between;margin-bottom:1rem;gap:1rem}.date-bar label{display:flex;align-items:center;gap:.5rem;color:var(--muted);font-size:.85rem}.date-bar input[type=date]{background:var(--surface);border:1px solid var(--border);color:#fff;padding:.35rem .5rem;border-radius:.4rem;font-size:.85rem;outline:none}.counter{font-size:.8rem;color:var(--muted);font-variant-numeric:tabular-nums}.empty{color:var(--muted);text-align:center;padding:2.5rem 1rem;font-size:.9rem}.student-list{list-style:none;display:flex;flex-direction:column;gap:.4rem}.student-row{display:flex;align-items:center;justify-content:space-between;background:var(--surface);border:1px solid var(--border);padding:.6rem .85rem;border-radius:.5rem;transition:border-color .15s}.student-row:hover{border-color:#ffffff2e}.student-name{font-weight:500;font-size:.95rem}.status-btns{display:flex;gap:.35rem;align-items:center}.status-btn{width:2rem;height:2rem;border-radius:.4rem;border:1px solid var(--border);background:transparent;color:var(--muted);font-weight:700;font-size:.75rem;cursor:pointer;transition:all .15s}.status-btn.present:hover,.status-btn.present.selected{background:var(--green);color:#000;border-color:var(--green)}.status-btn.late:hover,.status-btn.late.selected{background:var(--yellow);color:#000;border-color:var(--yellow)}.status-btn.absent:hover,.status-btn.absent.selected{background:var(--red);color:#fff;border-color:var(--red)}.remove-btn{width:2rem;height:2rem;border-radius:.4rem;border:1px solid transparent;background:transparent;color:var(--muted);font-size:.8rem;cursor:pointer;transition:all .15s}.remove-btn:hover{background:#ef444426;color:var(--red);border-color:#ef44444d}.history-table-wrap{overflow-x:auto;margin-bottom:1.5rem}.history-table{width:100%;border-collapse:collapse;font-size:.9rem}.history-table th{text-align:left;color:var(--muted);font-weight:500;font-size:.8rem;text-transform:uppercase;letter-spacing:.06em;padding:.5rem .75rem;border-bottom:1px solid var(--border)}.history-table td{padding:.6rem .75rem;border-bottom:1px solid var(--border)}.stat-present{color:var(--green);font-weight:600}.stat-late{color:var(--yellow);font-weight:600}.stat-absent{color:var(--red);font-weight:600}.rate-bar{position:relative;width:5rem;height:1.4rem;background:#ffffff0f;border-radius:.3rem;overflow:hidden}.rate-fill{position:absolute;top:0;left:0;height:100%;background:var(--green);opacity:.3;border-radius:.3rem;transition:width .3s}.rate-text{position:relative;z-index:1;font-size:.75rem;font-weight:600;display:flex;align-items:center;justify-content:center;height:100%}.day-records h3{font-size:1rem;margin-bottom:.75rem;color:var(--muted)}.day-card{background:var(--surface);border:1px solid var(--border);border-radius:.5rem;padding:.75rem;margin-bottom:.5rem}.day-card strong{display:block;margin-bottom:.5rem;font-size:.85rem}.day-summary{display:flex;flex-wrap:wrap;gap:.35rem}.badge{font-size:.75rem;padding:.2rem .5rem;border-radius:.3rem;background:#ffffff0d;border:1px solid var(--border)}.badge.present{color:var(--green);border-color:#22c55e4d}.badge.late{color:var(--yellow);border-color:#eab3084d}.badge.absent{color:var(--red);border-color:#ef44444d}.badge.none{color:var(--muted)}