:root{color-scheme:dark;font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;line-height:1.5;--bg: #0a0a0a;--surface: #141414;--border: rgba(255, 255, 255, .1);--text: #fafafa;--dim: rgba(255, 255, 255, .5);--accent: #3b82f6;--accent-hover: #2563eb;--green: #22c55e;--red: #ef4444;--yellow: #eab308}*{box-sizing:border-box;margin:0}html,body,#root{min-height:100vh;background:var(--bg);color:var(--text)}.app{max-width:960px;margin:0 auto;padding:2rem 1.5rem}.header{margin-bottom:2rem}.header h1{font-size:1.75rem;font-weight:700;letter-spacing:-.03em}.subtitle{color:var(--dim);font-size:.9rem;margin-top:.25rem}.layout{display:grid;grid-template-columns:1fr 1fr;gap:1.5rem}@media(max-width:700px){.layout{grid-template-columns:1fr}}.panel{background:var(--surface);border:1px solid var(--border);border-radius:.75rem;padding:1.25rem;min-height:320px}.panel h2{font-size:1.1rem;font-weight:600;margin-bottom:1rem;letter-spacing:-.01em}.inline-form{display:flex;gap:.5rem;margin-bottom:1rem}.grade-form{flex-wrap:wrap}.input{flex:1;min-width:0;padding:.5rem .75rem;background:#ffffff0d;border:1px solid var(--border);border-radius:.5rem;color:var(--text);font-size:.875rem;outline:none;transition:border-color .15s}.input:focus{border-color:var(--accent)}.input-sm{max-width:7rem}.input::placeholder{color:var(--dim)}.btn{padding:.5rem 1rem;border:none;border-radius:.5rem;font-size:.875rem;font-weight:500;cursor:pointer;white-space:nowrap;transition:background .15s}.btn-primary{background:var(--accent);color:#fff}.btn-primary:hover{background:var(--accent-hover)}.btn-icon{background:none;border:none;color:var(--dim);font-size:1.25rem;cursor:pointer;padding:0 .25rem;line-height:1;transition:color .15s}.btn-icon:hover{color:var(--red)}.student-list{list-style:none;padding:0;display:flex;flex-direction:column;gap:.375rem}.student-item{display:flex;align-items:center;justify-content:space-between;padding:.625rem .75rem;border-radius:.5rem;cursor:pointer;transition:background .15s;border:1px solid transparent}.student-item:hover{background:#ffffff0a}.student-item.selected{background:#3b82f61a;border-color:#3b82f64d}.student-info{display:flex;flex-direction:column;gap:.125rem}.student-name{font-weight:500;font-size:.95rem}.student-meta{font-size:.75rem;color:var(--dim)}.letter{font-weight:600;padding:0 .25rem;border-radius:.25rem;font-size:.7rem}.grade-A{color:var(--green)}.grade-B{color:#86efac}.grade-C{color:var(--yellow)}.grade-D{color:#fb923c}.grade-F{color:var(--red)}.grade-table{width:100%;border-collapse:collapse;font-size:.875rem;margin-bottom:1rem}.grade-table th{text-align:left;padding:.5rem;color:var(--dim);font-weight:500;font-size:.75rem;text-transform:uppercase;letter-spacing:.05em;border-bottom:1px solid var(--border)}.grade-table td{padding:.5rem;border-bottom:1px solid rgba(255,255,255,.04)}.grade-table tr:last-child td{border-bottom:none}.dim{color:var(--dim)}.score-cell{text-align:right}.score{font-weight:600;font-variant-numeric:tabular-nums}.score.pass{color:var(--green)}.score.fail{color:var(--red)}.summary{display:grid;grid-template-columns:repeat(4,1fr);gap:.5rem;padding-top:.75rem;border-top:1px solid var(--border)}.summary-item{display:flex;flex-direction:column;align-items:center;gap:.125rem}.summary-label{font-size:.65rem;text-transform:uppercase;letter-spacing:.06em;color:var(--dim)}.summary-value{font-size:1.1rem;font-weight:700;font-variant-numeric:tabular-nums}.empty{color:var(--dim);font-size:.85rem;text-align:center;padding:2rem 0}.empty-state{display:grid;place-items:center;height:100%;color:var(--dim);font-size:.9rem}input[type=number]::-webkit-inner-spin-button,input[type=number]::-webkit-outer-spin-button{-webkit-appearance:none;margin:0}input[type=number]{-moz-appearance:textfield}