:root{--bg:#f5f7fa;--ink:#172b3a;--muted:#788692;--line:#e4e9ee;--brand:#16796f;--soft:#e6f3ee;--white:#fff}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:14px/1.6 -apple-system,BlinkMacSystemFont,'PingFang SC','Microsoft YaHei',sans-serif}button,input,select{font:inherit}button,a,input,select{ -webkit-tap-highlight-color:transparent}button,a{touch-action:manipulation}a{color:inherit;text-decoration:none}button{cursor:pointer}button:disabled{opacity:.5;cursor:not-allowed}[hidden]{display:none!important}:focus-visible{outline:3px solid #55bbae;outline-offset:3px}.sidebar{position:fixed;inset:0 auto 0 0;width:232px;background:white;border-right:1px solid var(--line);padding:34px 22px;display:flex;flex-direction:column}.brand{display:flex;gap:12px;align-items:center;font-size:19px;font-weight:750}.logo{display:grid;place-items:center;width:39px;height:39px;border-radius:12px;background:var(--brand);color:white;font-size:22px}.caption{font-size:11px;letter-spacing:2px;color:var(--muted);margin:38px 12px 14px}.nav{display:grid;gap:7px}.nav button{border:0;background:transparent;padding:12px;border-radius:9px;text-align:left;color:#63717d;display:flex;justify-content:space-between}.nav button.active{background:var(--soft);color:var(--brand);font-weight:650}.nav button:hover{background:#f0f5f3}.nav small{color:#879790}.sidebar-foot{margin-top:auto;padding-top:32px;color:var(--muted);font-size:12px}.sidebar-foot a{display:block;margin-bottom:12px;color:var(--brand)}main{margin-left:232px;padding:0 46px 40px;max-width:1600px}.topbar{height:90px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line);gap:16px}.topbar .crumb{color:var(--muted);font-size:13px}.topbar .crumb span{color:var(--ink);margin-left:12px}.button{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:1px solid var(--line);background:#fff;border-radius:8px;padding:9px 16px;white-space:nowrap}.button.primary{background:var(--brand);border-color:var(--brand);color:#fff}.button:hover{filter:brightness(.97)}.hero{display:flex;justify-content:space-between;align-items:center;gap:24px;padding:40px 0 30px}.eyebrow{font-size:11px;font-weight:650;letter-spacing:2px;color:var(--brand)}h1{font-size:32px;letter-spacing:-1px;line-height:1.3;margin:10px 0 12px}p{margin:0;color:var(--muted)}.hero-art{display:flex;gap:8px;align-items:end;padding:0 15px}.hero-art span{display:grid;place-items:center;border:1px solid #cbded5;background:#e4efe9;border-radius:14px;width:66px;height:76px;font:600 23px monospace;color:#49756a;transform:rotate(-8deg)}.hero-art span:nth-child(2){height:100px;background:#f3ebd8;border-color:#e6dbbd;transform:rotate(6deg);color:#9a834b}.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-bottom:32px}.stat{padding:18px 23px;border:1px solid var(--line);border-radius:12px;background:white;display:flex;align-items:center;justify-content:space-between}.stat strong{font-size:28px;font-weight:650}.stat span{color:var(--muted);font-size:12px}.toolbar{display:flex;gap:12px;margin-bottom:23px;align-items:center}.search{flex:1;position:relative}.search input{width:100%;padding:12px 15px;border:1px solid var(--line);border-radius:9px;background:white}.toolbar select,select{border:1px solid var(--line);border-radius:8px;background:#fff;padding:10px;color:var(--ink)}.section-title{display:flex;justify-content:space-between;align-items:center;margin:20px 0 17px}.section-title h2{font-size:18px;margin:0}.section-title span{font-size:12px;color:var(--muted)}.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.card{background:white;border:1px solid var(--line);border-radius:13px;overflow:hidden;display:flex;flex-direction:column;transition:transform .18s,box-shadow .18s}.card:hover{transform:translateY(-3px);box-shadow:0 8px 22px #192b3b0a}.card-top{margin:17px 18px 0;display:flex;justify-content:space-between;align-items:center}.course-icon{display:grid;place-items:center;width:42px;height:42px;border-radius:11px;background:var(--soft);color:var(--brand);font:600 15px monospace}.badge{font-size:11px;color:var(--brand);background:var(--soft);padding:3px 9px;border-radius:5px}.badge.unopened{color:#9a782c;background:#faf1db}.card-body{padding:18px;flex:1}.card-body small{font-size:11px;color:var(--muted)}.card h3{font-size:16px;line-height:1.65;margin:8px 0 12px;overflow-wrap:anywhere;font-weight:600}.card-bottom{display:flex;justify-content:space-between;align-items:center;padding:13px 18px;border-top:1px solid #f0f2f4;font-size:12px;color:var(--muted)}.card-bottom a{color:var(--brand);font-weight:600}.empty{grid-column:1/-1;padding:65px 20px;text-align:center;border:1px dashed #cdd8d8;border-radius:12px;color:var(--muted)}.footer{margin-top:38px;text-align:center;font-size:11px;color:#94a0a9}.login-wrap{min-height:100vh;display:grid;place-items:center;padding:24px;background:radial-gradient(ellipse at 15% 20%,#e0efe7,transparent 55%),var(--bg)}.login-card{width:min(420px,100%);padding:36px;background:white;border:1px solid var(--line);border-radius:18px;box-shadow:0 20px 70px #204e3f09}.login-card h1{font-size:25px;margin-top:30px}.login-card label{display:block;margin-top:20px;font-size:13px}.login-card input{display:block;width:100%;border:1px solid var(--line);border-radius:8px;padding:11px;margin-top:7px}.login-card .button{width:100%;margin-top:26px}.error{color:#b34a3e;min-height:24px;margin-top:12px;font-size:13px}.upload{background:white;border:1px solid var(--line);border-radius:12px;padding:22px;margin-bottom:26px}.upload h2{font-size:16px;margin:0 0 5px}.upload p{font-size:12px;margin-bottom:18px}.upload-row{display:flex;align-items:center;gap:12px;flex-wrap:wrap}.upload-row input{flex:1;min-width:200px}.table{border:1px solid var(--line);background:white;border-radius:12px;overflow:hidden}.file-row{display:flex;align-items:center;gap:18px;padding:17px 20px;border-bottom:1px solid var(--line)}.file-row:last-child{border:0}.file-detail{flex:1;min-width:0}.file-detail a{font-weight:550;overflow-wrap:anywhere}.file-detail small{display:block;color:var(--muted);font-size:11px;margin-top:4px}.danger{color:#b45445}.row-actions{display:flex;gap:8px;align-items:center}.row-actions .button{font-size:12px;padding:8px 11px}#toast{position:fixed;bottom:28px;left:50%;transform:translateX(-50%);padding:12px 24px;border-radius:10px;background:#203d37;color:white;z-index:50;max-width:90vw;box-shadow:0 8px 32px #0002}.loading{color:var(--muted);padding:40px;text-align:center}@media(min-width:1600px){main{margin-right:auto}}@media(max-width:1150px){.grid{grid-template-columns:repeat(2,minmax(0,1fr))}main{padding:0 28px 30px}.sidebar{width:200px;padding:28px 16px}main{margin-left:200px}}@media(max-width:720px){.sidebar{position:static;width:auto;padding:18px;border-right:0;border-bottom:1px solid var(--line)}.caption,.sidebar-foot{display:none}.nav{display:flex;overflow:auto;margin-top:18px;gap:5px}.nav button{white-space:nowrap;gap:12px;padding:8px 12px}.brand{font-size:17px}main{margin:0;padding:0 18px 24px}.topbar{height:67px}.hero{padding:26px 0}.hero-art{display:none}h1{font-size:27px}.stats{gap:8px;margin-bottom:22px}.stat{padding:12px;display:grid;gap:5px}.stat strong{font-size:23px}.toolbar{flex-wrap:wrap}.search{min-width:100%}.grid{gap:12px}.card h3{font-size:14px}.card-body,.card-bottom{padding:13px}.card-top{margin:13px 13px 0}.file-row{align-items:flex-start;flex-wrap:wrap;padding:15px;gap:12px}.file-detail{min-width:100%}.row-actions{width:100%}.upload-row>*{width:100%}.hero p{font-size:12px}}@media(max-width:420px){.grid{grid-template-columns:1fr}}@media(prefers-reduced-motion:reduce){*{transition:none!important}}
.course-tabs{display:flex;flex-wrap:wrap;gap:10px;margin-bottom:24px}.course-tabs button{border:1px solid var(--line);padding:9px 17px;border-radius:8px;background:white;color:var(--muted)}.course-tabs button.active{background:var(--soft);border-color:#9cc8b9;color:var(--brand);font-weight:600}.course-tabs small{margin-left:10px}.move-dialog{border:1px solid var(--line);border-radius:14px;padding:28px;width:min(500px,90vw);color:var(--ink)}.move-dialog::backdrop{background:#182b3966}.move-dialog select{width:100%;margin:18px 0}.move-dialog p{overflow-wrap:anywhere}.row-actions{flex-wrap:wrap}