:root{--bg:#f5f6f8;--card:#fff;--border:#e0e2e7;--text:#1f2430;--muted:#6b7280;--primary:#2f5fdb;--error:#d0342c;--success:#1a7f37;font-family:system-ui,-apple-system,Segoe UI,sans-serif}*{box-sizing:border-box}body{background:var(--bg);color:var(--text);margin:0}.loading{text-align:center;color:var(--muted);padding:3rem}.auth-page{justify-content:center;align-items:center;min-height:100vh;display:flex}.auth-card{background:var(--card);border:1px solid var(--border);border-radius:12px;flex-direction:column;gap:.9rem;width:320px;padding:2rem;display:flex;box-shadow:0 4px 20px #0000000d}.auth-card h1{margin:0 0 .5rem;font-size:1.25rem}label{color:var(--muted);flex-direction:column;gap:.3rem;font-size:.9rem;display:flex}input,textarea{border:1px solid var(--border);border-radius:6px;padding:.5rem .6rem;font-family:inherit;font-size:.95rem}button{cursor:pointer;background:var(--primary);color:#fff;border:none;border-radius:6px;padding:.6rem 1rem;font-size:.95rem}button:disabled{opacity:.6;cursor:not-allowed}.link-button{color:var(--primary);background:0 0;padding:0;font-size:.85rem;text-decoration:underline}.error{color:var(--error);margin:0;font-size:.85rem}.success{color:var(--success);margin:0;font-size:.85rem}.app-shell{min-height:100vh}.app-header{background:var(--card);border-bottom:1px solid var(--border);justify-content:space-between;align-items:center;padding:.9rem 1.5rem;display:flex}.app-header-left{align-items:center;gap:2rem;display:flex}.app-title{font-weight:600}.app-nav{gap:1.2rem;display:flex}.app-nav a{color:var(--muted);font-size:.9rem;text-decoration:none}.app-nav a:hover{color:var(--primary)}.app-user{color:var(--muted);align-items:center;gap:1rem;font-size:.9rem;display:flex}.app-main{max-width:900px;margin:0 auto;padding:2rem 1.5rem}.dashboard h2{margin-top:0}.inline-form{flex-wrap:wrap;gap:.6rem;margin-bottom:1.5rem;display:flex}.inline-form input{flex:1;min-width:160px}.stacked-form{flex-direction:column;gap:.9rem;max-width:480px;display:flex}.card-list{flex-direction:column;gap:.8rem;padding:0;list-style:none;display:flex}.card{background:var(--card);border:1px solid var(--border);border-radius:8px;padding:1rem}.card ul{margin:.5rem 0 0;padding-left:1.2rem;font-size:.9rem}.muted{color:var(--muted)}.teacher-row{flex-wrap:wrap;gap:.4rem;margin:.4rem 0;display:flex}.pill{background:#eef1f8;border-radius:999px;align-items:center;gap:.3rem;padding:.15rem .3rem .15rem .7rem;font-size:.85rem;display:inline-flex}.pill-remove{color:var(--muted);background:0 0;border-radius:50%;width:1.3rem;height:1.3rem;padding:0;font-size:1rem;line-height:1}.pill-remove:hover{color:var(--text);background:#dde1ea}.card ul li{margin-bottom:.6rem}.credentials-box{background:#eaf7ec;border:1px solid #b9e3bd;border-radius:8px;margin-bottom:1.5rem;padding:1rem 2.2rem 1rem 1rem;position:relative}.credentials-box code{background:#0000000f;border-radius:4px;padding:.1rem .4rem;font-size:.95rem}.credentials-box p{margin:.3rem 0}.storage-bar{background:var(--border);border-radius:999px;width:100%;height:8px;margin-top:.5rem;overflow:hidden}.storage-bar-fill{background:var(--primary);border-radius:999px;height:100%;transition:width .2s}.credentials-close{color:var(--muted);background:0 0;border-radius:50%;width:1.6rem;height:1.6rem;padding:0;font-size:1.1rem;line-height:1;position:absolute;top:.5rem;right:.5rem}.credentials-close:hover{color:var(--text);background:#00000014}.data-table{border-collapse:collapse;background:var(--card);border:1px solid var(--border);border-radius:8px;width:100%;font-size:.9rem;overflow:hidden}.data-table th,.data-table td{text-align:left;border-bottom:1px solid var(--border);padding:.6rem .8rem}.data-table th{color:var(--muted);text-transform:uppercase;letter-spacing:.03em;font-size:.8rem;font-weight:500}.data-table tbody tr:last-child td{border-bottom:none}.todo-section{border:1px dashed var(--border);color:var(--muted);border-radius:8px;margin-top:2rem;padding:1rem;font-size:.9rem}.todo-section h3{margin-top:0;font-size:.95rem}.tabs{border-bottom:1px solid var(--border);gap:.5rem;margin-bottom:1.2rem;display:flex}.tab{color:var(--muted);background:0 0;border-bottom:2px solid #0000;border-radius:0;margin-right:1rem;padding:.5rem .2rem}.tab.active{color:var(--text);border-bottom-color:var(--primary);font-weight:600}.messages-layout{grid-template-columns:minmax(240px,320px) 1fr;align-items:start;gap:1.2rem;display:grid}.message-list{flex-direction:column;gap:.4rem;max-height:70vh;margin:0;padding:0;list-style:none;display:flex;overflow-y:auto}.message-row{background:var(--card);border:1px solid var(--border);cursor:pointer;border-radius:8px;padding:.6rem .8rem;font-size:.9rem}.message-row:hover{border-color:var(--primary)}.message-row.selected{border-color:var(--primary);box-shadow:0 0 0 1px var(--primary)}.message-row.unread{font-weight:600}.message-row.unread:before{content:"";background:var(--primary);border-radius:50%;width:6px;height:6px;margin-right:.4rem;display:inline-block}.message-row-top{justify-content:space-between;gap:.5rem;margin-bottom:.2rem;font-size:.8rem;display:flex}.message-detail{background:var(--card);border:1px solid var(--border);border-radius:8px;padding:1.2rem}.message-detail h3{margin-top:0}.checkbox-list{border:1px solid var(--border);border-radius:8px;flex-direction:column;gap:.3rem;max-height:220px;padding:.6rem;display:flex;overflow-y:auto}.checkbox-item{color:var(--text);flex-direction:row;align-items:center;gap:.5rem;font-size:.9rem}.checkbox-item input{width:auto}