:root{--ink:#f5f7fb;--muted:#9ba8bd;--line:#263552;--panel:#111c31;--panel2:#17243d;--bg:#0b1324;--mint:#5ce1c4;--orange:#ff9d62;--red:#ff7185;--blue:#80aaff;--shadow:0 20px 50px #04091455;font-family:Inter,"PingFang SC","Microsoft YaHei",system-ui,sans-serif}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font-size:16px;line-height:1.55}a{color:inherit;text-decoration:none}button,input,textarea,select{font:inherit}button{cursor:pointer;border:0}.landing{min-height:100vh;display:grid;place-items:center;padding:24px;background:radial-gradient(circle at 18% 10%,#17365e 0,transparent 35%),radial-gradient(circle at 90% 85%,#12423f 0,transparent 28%),var(--bg)}.landing-card{width:min(620px,100%);padding:56px 48px;text-align:center;background:#101b30cc;border:1px solid var(--line);border-radius:28px;box-shadow:var(--shadow);backdrop-filter:blur(16px)}.brand-mark{display:grid;place-items:center;margin:0 auto 18px;width:58px;height:58px;border-radius:18px;background:var(--mint);color:var(--bg);font-size:28px}.eyebrow{font-size:12px;letter-spacing:.18em;color:var(--mint);font-weight:700}.landing h1{font-size:clamp(34px,7vw,56px);line-height:1.1;margin:10px 0 16px;letter-spacing:-.05em}.lede{color:var(--muted);margin:0 auto 36px;max-width:430px}.entry-grid{display:grid;gap:12px;text-align:left}.entry-card{display:flex;align-items:center;gap:15px;padding:18px;border:1px solid var(--line);background:var(--panel);border-radius:16px;transition:.2s}.entry-card:hover{transform:translateY(-2px);border-color:var(--mint)}.entry-icon{display:grid;place-items:center;width:42px;height:42px;border-radius:12px;background:#243450;color:var(--mint);font-size:22px}.entry-card strong,.entry-card small{display:block}.entry-card small{color:var(--muted);font-size:13px}.arrow{margin-left:auto;color:var(--muted);font-size:22px}.demo-note{color:#667691;font-size:12px;margin:28px 0 0}.shell{display:grid;grid-template-columns:250px 1fr;min-height:100vh}.sidebar{border-right:1px solid var(--line);padding:28px 20px;background:#0e192d}.logo{display:flex;align-items:center;gap:10px;font-weight:800;font-size:18px;margin-bottom:52px}.logo-mark{display:grid;place-items:center;width:32px;height:32px;border-radius:10px;background:var(--mint);color:var(--bg)}.side-label{font-size:12px;color:#687994;letter-spacing:.1em;margin:0 12px 10px}.nav{display:grid;gap:6px}.nav button{display:flex;align-items:center;gap:11px;width:100%;text-align:left;color:var(--muted);background:transparent;padding:12px;border-radius:10px}.nav button.active,.nav button:hover{background:var(--panel2);color:var(--ink)}.profile-mini{position:absolute;bottom:24px;color:var(--muted);font-size:13px;padding:12px}.main{min-width:0;padding:36px clamp(20px,5vw,64px);max-width:1400px;width:100%}.topbar{display:flex;justify-content:space-between;align-items:flex-start;gap:16px;margin-bottom:28px}.topbar h1{font-size:30px;line-height:1.2;margin:0 0 5px;letter-spacing:-.04em}.muted{color:var(--muted)}.tag{display:inline-flex;padding:4px 9px;border-radius:999px;font-size:12px;font-weight:700;background:#20314b;color:var(--blue)}.tag.mint{background:#143e3b;color:var(--mint)}.tag.orange{background:#4a2e26;color:var(--orange)}.btn{padding:10px 15px;border-radius:10px;background:var(--panel2);color:var(--ink);border:1px solid var(--line);font-weight:700}.btn:hover{border-color:var(--mint)}.btn.primary{background:var(--mint);color:var(--bg);border-color:var(--mint)}.btn.orange{background:var(--orange);color:#24140d;border-color:var(--orange)}.btn.danger{color:var(--red)}.grid{display:grid;gap:16px}.stats{grid-template-columns:repeat(4,minmax(0,1fr));margin-bottom:22px}.card{background:var(--panel);border:1px solid var(--line);border-radius:16px;padding:20px}.stat-label{color:var(--muted);font-size:13px}.stat-value{font-size:30px;line-height:1.1;font-weight:800;margin:7px 0}.stat-note{font-size:12px;color:#73839d}.two-col{grid-template-columns:1.4fr 1fr}.section-head{display:flex;justify-content:space-between;align-items:center;gap:10px;margin-bottom:16px}.section-head h2{font-size:18px;margin:0}.course-row,.student-row{display:flex;align-items:center;gap:12px;padding:13px 0;border-bottom:1px solid #23304a}.course-row:last-child,.student-row:last-child{border:0}.avatar{display:grid;place-items:center;flex:none;width:38px;height:38px;border-radius:12px;background:#233452;color:var(--mint);font-weight:800}.grow{flex:1;min-width:0}.grow strong{display:block;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.sub{font-size:13px;color:var(--muted)}.row-actions{display:flex;gap:8px;flex-wrap:wrap}.check{color:var(--mint)}.pending{color:var(--orange)}.bar{height:8px;border-radius:99px;background:#263650;overflow:hidden}.bar i{display:block;height:100%;background:var(--mint);border-radius:inherit}.toolbar{display:flex;gap:10px;flex-wrap:wrap}.form-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:13px}.field{display:grid;gap:6px}.field.full{grid-column:1/-1}.field label{font-size:13px;color:var(--muted)}input,textarea,select{width:100%;color:var(--ink);background:#0c1628;border:1px solid var(--line);border-radius:10px;padding:11px 12px;outline:0}textarea{min-height:110px;resize:vertical}input:focus,textarea:focus,select:focus{border-color:var(--mint)}.modal{position:fixed;inset:0;display:grid;place-items:center;background:#050a14aa;padding:20px;z-index:5}.modal .card{width:min(580px,100%);box-shadow:var(--shadow);max-height:90vh;overflow:auto}.toast{position:fixed;right:22px;bottom:22px;background:var(--mint);color:var(--bg);padding:12px 16px;border-radius:10px;font-weight:700;z-index:10}.timeline{position:relative;padding-left:25px}.timeline:before{content:"";position:absolute;left:6px;top:6px;bottom:6px;width:2px;background:#29415a}.timeline-item{position:relative;padding:0 0 24px}.timeline-item:before{content:"";position:absolute;left:-25px;top:6px;width:12px;height:12px;border:3px solid var(--bg);border-radius:50%;background:var(--mint)}.timeline-item h3{font-size:16px;margin:0 0 4px}.timeline-item p{margin:4px 0;color:var(--muted)}.photo{width:100%;height:120px;object-fit:cover;border-radius:10px;background:#243450}.notice{padding:14px 16px;background:#173237;border:1px solid #245a55;color:#b7f5e6;border-radius:12px;margin-bottom:18px}.empty{text-align:center;padding:34px 10px;color:var(--muted)}.mobile-nav{display:none}@media(max-width:900px){.shell{display:block}.sidebar{display:none}.main{padding:24px 16px 88px}.stats{grid-template-columns:repeat(2,1fr)}.two-col{grid-template-columns:1fr}.mobile-nav{display:flex;position:fixed;bottom:0;left:0;right:0;background:#101b30f2;border-top:1px solid var(--line);z-index:4;padding:7px 10px;justify-content:space-around}.mobile-nav button{background:transparent;color:var(--muted);font-size:12px;padding:5px}.mobile-nav button.active{color:var(--mint)}.profile-mini{display:none}.landing-card{padding:40px 22px}}