:root{--navy:#003057;--ink:#14213d;--paper:#fafaf6;--white:#fff;--rule:#e5e7eb;--coral:#f47b55;--muted:#526477;--pale:#eef3f6;--success:#146c43;--warning:#8a5a00;--error:#b3261e}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font-family:"Noto Sans SC","Source Han Sans CN","Microsoft YaHei",Arial,sans-serif;font-size:14px;line-height:1.6}button,input,textarea,select{font:inherit}button{cursor:pointer}.shell{min-height:100vh;display:grid;grid-template-columns:300px 1fr}.sidebar{position:sticky;top:0;height:100vh;overflow:auto;background:var(--white);border-right:1px solid var(--rule);padding:28px 16px}.brand{display:block;width:218px;margin:0 8px 18px}.brand img{width:100%;height:auto;display:block}.service-label{margin:0 8px 20px;color:var(--navy);font-size:14px;font-weight:700;line-height:1.45}.search{width:100%;padding:11px 12px;border:1px solid var(--rule);border-radius:0;background:#fff;color:var(--ink);margin:0 0 16px}.search::placeholder{color:#64748b}.student-list{display:grid;gap:2px}.student-item{width:100%;border:0;border-left:3px solid transparent;border-radius:0;background:transparent;color:var(--ink);text-align:left;padding:11px 10px;transition:background .18s,border-color .18s}.student-item:hover,.student-item.active{background:var(--pale);border-left-color:var(--coral)}.student-item strong,.student-item span{display:block}.student-item span{margin-top:3px;color:var(--muted);font-size:12px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.add-student{width:100%;margin-top:18px;padding:11px;border:1px solid var(--coral);border-radius:0;background:var(--coral);color:var(--ink);font-weight:700}.main{width:100%;max-width:1240px;margin:auto;padding:36px}.topline{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-bottom:24px;padding-bottom:16px;border-bottom:1px solid var(--rule)}.topline p{margin:0;color:var(--muted);font-size:12px;font-weight:700;letter-spacing:.08em}.topline h1{margin:5px 0 0;color:var(--navy);font-size:28px;letter-spacing:-.02em}.btn{border:0;border-radius:0;padding:10px 14px;font-weight:700}.primary{background:var(--coral);color:var(--ink)}.secondary{background:var(--navy);color:#fff}.outline{border:1px solid var(--navy);background:#fff;color:var(--navy)}.danger{background:#fff0ef;color:var(--error)}.alerts{display:grid;gap:10px;margin-bottom:18px}.alert{display:flex;align-items:center;justify-content:space-between;gap:12px;border-left:4px solid var(--warning);border-radius:0;background:#fff9ec;padding:12px 14px}.alert.expired{border-color:var(--error);background:#fff0ef}.alert button{border:0;background:transparent;color:var(--navy);text-decoration:underline}.empty{border:1px dashed #b9c9d8;border-radius:0;background:#fff;padding:52px;text-align:center;color:var(--muted)}.profile{display:grid;gap:18px}.card{border:1px solid var(--rule);border-radius:0;background:#fff;padding:22px;box-shadow:none}.student-header{display:flex;align-items:start;justify-content:space-between;gap:18px;border-top:4px solid var(--navy)}.student-header h2{margin:0 0 6px;color:var(--navy);font-size:22px}.student-header p{margin:0;color:var(--muted)}.badges,.actions{display:flex;gap:8px;flex-wrap:wrap}.badges{margin-top:13px}.badge{border-radius:0;background:var(--pale);color:var(--navy);padding:5px 9px;font-size:12px}.badge.warn{background:#fff2d6;color:var(--warning)}.info-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.info-grid div{border-left:2px solid var(--rule);padding:13px}.info-grid label{display:block;margin-bottom:5px;color:var(--muted);font-size:12px}.info-grid strong{font-weight:650}.section-title{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:15px}.section-title h3{margin:0;color:var(--navy);font-size:16px}.usage,.details{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}.usage-card{border:1px solid var(--rule);border-radius:0;background:#fff;padding:18px}.usage-card h3{margin:0 0 10px;color:var(--navy)}.usage-count{color:var(--navy);font-size:28px;font-weight:800}.usage-count small{color:var(--muted);font-size:14px;font-weight:400}.progress{height:6px;overflow:hidden;background:#e9eef4;margin:12px 0 7px}.progress i{display:block;height:100%;background:var(--coral)}.usage-card p,.hint{margin:0;color:var(--muted)}.hint{font-size:13px}.table-wrap{overflow:auto}table{width:100%;border-collapse:collapse}th,td{padding:11px 9px;border-bottom:1px solid var(--rule);text-align:left;white-space:nowrap}th{color:var(--muted);font-size:12px;font-weight:700}.modal-backdrop{position:fixed;inset:0;z-index:10;display:grid;place-items:center;background:#14213d99;padding:20px}.modal{width:100%;max-width:750px;max-height:90vh;overflow:auto;border-top:4px solid var(--navy);border-radius:0;background:#fff;padding:24px}.modal h2{margin:0 0 8px;color:var(--navy)}.modal .intro{margin:0 0 18px;color:var(--muted)}.form-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:13px}.field{display:grid;gap:6px}.field.full{grid-column:1/-1}.field label{color:var(--ink);font-weight:700}.field input,.field textarea,.field select{width:100%;border:1px solid #bdc7d1;border-radius:0;background:#fff;padding:10px}.field textarea{min-height:80px;resize:vertical}.modal-footer{display:flex;justify-content:flex-end;gap:9px;margin-top:20px}.tabs{display:flex;gap:8px;margin:10px 0 16px}.tab{border:1px solid var(--rule);border-radius:0;background:#fff;padding:8px 12px}.tab.active{border-color:var(--navy);background:var(--pale);color:var(--navy)}.paste{min-height:150px;font-family:ui-monospace,Consolas,monospace;font-size:13px}.file-row{display:flex;align-items:center;gap:10px;flex-wrap:wrap}.small{color:var(--muted);font-size:12px}.notice{position:fixed;right:18px;bottom:18px;z-index:20;border-radius:0;background:var(--navy);color:#fff;padding:13px 17px}.delete-row{margin-top:25px;border-top:1px solid var(--rule);padding-top:16px}.empty-table{text-align:center;color:var(--muted);padding:20px}button:focus-visible,input:focus-visible,textarea:focus-visible,a:focus-visible{outline:3px solid var(--coral);outline-offset:2px}@media(prefers-reduced-motion:reduce){*,*:before,*:after{scroll-behavior:auto!important;transition:none!important;animation:none!important}}@media(max-width:900px){.shell{grid-template-columns:1fr}.sidebar{position:static;height:auto}.student-list{max-height:240px;overflow:auto}.main{padding:24px}.info-grid,.usage,.details{grid-template-columns:1fr}.student-header,.topline{align-items:flex-start;flex-direction:column}}@media(max-width:560px){.form-grid{grid-template-columns:1fr}.main{padding:16px}.card{padding:16px}.modal{padding:18px}.topline h1{font-size:23px}.brand{width:205px}}