@import"https://fonts.googleapis.com/css2?family=Source+Sans+3:wght@400;600;700&display=swap";:root{font-family:"Source Sans 3",Segoe UI,Helvetica Neue,Arial,sans-serif;line-height:1.5;font-weight:400;color:#1f2933;background-color:#f4f6f8;font-synthesis:none;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}a{color:inherit;text-decoration:none}a:hover{text-decoration:underline}body{margin:0;min-width:320px;min-height:100vh;background-color:#f4f6f8}#root{width:100%}button,select{font-family:inherit}:root{--bg: #edf1f7;--panel: #ffffff;--text: #1f2933;--muted: #5f6b7a;--border: #dce3ee;--accent: #2f6fed;--accent-strong: #2155d6;--accent-soft: #e6efff;--shadow: 0 16px 40px rgba(25, 42, 70, .12);--shadow-soft: 0 10px 24px rgba(25, 42, 70, .1);--topbar-height: 72px}.app{min-height:100vh;position:relative;background:radial-gradient(circle at top left,#f8fbff,#eef2f9 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var(--border);box-shadow:var(--shadow)}.table-scroll{overflow-x:auto}.submissions-table{width:100%;border-collapse:collapse;min-width:760px}.submissions-table th,.submissions-table td{padding:14px 16px;text-align:left;font-size:14px}.submissions-table thead th{font-size:12px;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);background:#f8fafc;border-bottom:1px solid var(--border)}.submissions-table tbody tr{border-bottom:1px solid var(--border)}.submissions-table tbody tr:last-child{border-bottom:none}.submissions-table tbody tr:hover{background:#f9fbff}.cell-time{white-space:nowrap;color:var(--muted)}.download-link{font-weight:600;color:var(--accent);background:none;border:none;padding:0;cursor:pointer}.empty-state{text-align:center;color:var(--muted);padding:24px 16px}.dashboard-tabs{display:flex;gap:12px;padding:6px;border-radius:999px;background:#ffffffb3;border:1px solid rgba(220,227,238,.7);margin-bottom:20px;flex-wrap:wrap}.dashboard-tab{border-radius:999px;padding:10px 18px;border:1px solid transparent;background:#fff;font-weight:700;cursor:pointer;position:relative;overflow:hidden;transition:color .2s ease,transform .2s ease,box-shadow .2s ease}.dashboard-tab:after{content:"";position:absolute;left:14px;right:14px;bottom:6px;height:3px;border-radius:999px;background:#2f6fed99;transform:scaleX(.2);opacity:0;transition:transform .25s ease,opacity .25s ease}.dashboard-tab.is-active{background:var(--accent);color:#fff;box-shadow:0 12px 24px #2f6fed40}.dashboard-tab.is-active:after{opacity:1;transform:scaleX(1);background:#fffc}.dashboard-tab:hover{transform:translateY(-2px)}.student-group-list{display:grid;gap:14px}.student-group-card{border-radius:16px;border:1px solid var(--border);background:#fff;box-shadow:var(--shadow-soft);overflow:hidden}.student-group-header{width:100%;border:none;background:transparent;padding:16px 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