:root{color-scheme:light;--ink:#17211b;--muted:#68756d;--line:#dfe5e0;--paper:#fff;--canvas:#f3f5f1;--brand:#176b47;--brand-dark:#0c4b31;--accent:#d6a44a;--danger:#b63838;--shadow:0 20px 60px rgba(20,44,31,.12);font-family:"Segoe UI","Microsoft YaHei",sans-serif}*{box-sizing:border-box}body{margin:0;background:var(--canvas);color:var(--ink)}button,input,textarea,select{font:inherit}button{cursor:pointer}.login-view{min-height:100vh;display:grid;place-items:center;padding:24px;background:radial-gradient(circle at 15% 20%,#d9ebdf 0,transparent 35%),linear-gradient(135deg,#f7f4ec,#eef4ef)}.login-card{width:min(440px,100%);padding:42px;background:rgba(255,255,255,.94);border:1px solid rgba(255,255,255,.9);border-radius:24px;box-shadow:var(--shadow)}.brand-mark{width:58px;height:58px;display:grid;place-items:center;background:var(--brand);color:#fff;border-radius:17px;font-weight:800;letter-spacing:-2px;font-size:25px}.brand-mark.small{width:42px;height:42px;border-radius:12px;font-size:18px}.eyebrow{margin:22px 0 6px;color:var(--brand);font-size:11px;letter-spacing:.18em;font-weight:750}.login-card h1,.topbar h1,.toolbar h2,.modal h2{margin:0}.muted,.hint{color:var(--muted);line-height:1.6}.login-card label,.modal label{display:grid;gap:7px;margin-top:18px;font-size:13px;font-weight:650}input,textarea,select{width:100%;border:1px solid var(--line);border-radius:10px;background:#fff;padding:11px 12px;color:var(--ink);outline:none}input:focus,textarea:focus,select:focus{border-color:var(--brand);box-shadow:0 0 0 3px rgba(23,107,71,.1)}button{border:0;border-radius:10px;padding:10px 15px;font-weight:700}.primary{background:var(--brand);color:#fff}.primary:hover{background:var(--brand-dark)}.secondary{background:#edf1ed;color:var(--ink)}.wide{width:100%;margin-top:25px}.error{min-height:20px;color:var(--danger);font-size:13px}.app{min-height:100vh;display:grid;grid-template-columns:245px 1fr}.sidebar{position:sticky;top:0;height:100vh;padding:26px 18px;background:#13271e;color:#fff;display:flex;flex-direction:column}.brand{display:flex;align-items:center;gap:12px;padding:0 8px 30px}.brand div{display:grid}.brand small{color:#95a89e;margin-top:2px}.sidebar nav{display:grid;gap:7px}.nav{width:100%;text-align:left;background:transparent;color:#aebbb4;padding:12px 14px}.nav:hover,.nav.active{background:rgba(255,255,255,.09);color:#fff}.logout{margin-top:auto}.workspace{min-width:0}.topbar{height:108px;padding:0 42px;display:flex;align-items:center;justify-content:space-between;background:rgba(255,255,255,.8);border-bottom:1px solid var(--line)}.topbar .eyebrow{margin:0 0 5px}.operator{padding:8px 12px;background:#e7eee9;border-radius:999px;color:var(--brand);font-size:13px}.panel{padding:34px 42px}.toolbar{display:flex;align-items:center;justify-content:space-between;gap:20px;margin-bottom:25px}.toolbar p{margin:5px 0 0}.course-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(290px,1fr));gap:18px}.course-card{background:var(--paper);border:1px solid var(--line);border-radius:16px;overflow:hidden}.course-cover{height:145px;background:linear-gradient(135deg,#d9e7dc,#eff1e6);display:grid;place-items:center;color:var(--brand);font-weight:800;background-size:cover;background-position:center}.course-body{padding:18px}.course-body h3{margin:0 0 8px;font-size:18px}.course-body p{height:44px;overflow:hidden;margin:0 0 16px;color:var(--muted);font-size:13px;line-height:1.6}.meta{display:flex;align-items:center;justify-content:space-between;margin-bottom:16px}.price{font-size:20px;font-weight:800;color:var(--brand)}.badge{font-size:12px;border-radius:999px;padding:5px 9px;background:#edf1ed;color:#5d6a62}.badge.live{background:#e0f0e6;color:var(--brand)}.card-actions{display:flex;gap:8px}.card-actions button{flex:1}.danger-ghost{background:#fff1f1;color:var(--danger)}.table-wrap{overflow:auto;background:#fff;border:1px solid var(--line);border-radius:15px}table{width:100%;border-collapse:collapse;min-width:750px}th,td{text-align:left;padding:15px 17px;border-bottom:1px solid var(--line);font-size:13px}th{color:var(--muted);font-size:12px;background:#fafbf9}tbody tr:last-child td{border-bottom:0}.text-button{padding:6px 8px;color:var(--brand);background:transparent}.text-button.danger{color:var(--danger)}dialog{border:0;padding:0;background:transparent}dialog::backdrop{background:rgba(13,25,19,.55);backdrop-filter:blur(4px)}.modal{width:min(620px,calc(100vw - 28px));max-height:90vh;overflow:auto;padding:27px;background:#fff;border-radius:18px;box-shadow:var(--shadow)}.modal.large{width:min(780px,calc(100vw - 28px))}.modal.extra-large{width:min(940px,calc(100vw - 28px))}.modal-head{display:flex;justify-content:space-between;align-items:start}.modal-head .eyebrow{margin:0 0 5px}.icon-button{padding:3px 10px;background:transparent;font-size:28px;color:var(--muted)}.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:0 16px}.span-2{grid-column:span 2}.checkbox{display:flex!important;grid-template-columns:auto 1fr!important;align-items:center;justify-content:start}.checkbox input{width:auto}.actions{display:flex;justify-content:flex-end;gap:9px;margin-top:25px}.cover-preview{min-height:90px;margin-top:12px;border:1px dashed var(--line);border-radius:11px;display:grid;place-items:center;color:var(--muted);background-size:cover;background-position:center}.inline-form{display:grid;grid-template-columns:1fr 95px auto;gap:9px;margin:20px 0}.chapter-list{display:grid;gap:13px}.chapter{border:1px solid var(--line);border-radius:13px;overflow:hidden}.chapter-head{padding:12px 14px;background:#f6f8f5;display:flex;justify-content:space-between;align-items:center}.chapter-head h3{margin:0;font-size:15px}.lesson-row{display:grid;grid-template-columns:1fr auto auto;align-items:center;gap:8px;padding:11px 14px;border-top:1px solid var(--line);font-size:13px}.empty{padding:45px;text-align:center;color:var(--muted);background:#fff;border:1px dashed var(--line);border-radius:14px}.toast{position:fixed;right:24px;bottom:24px;transform:translateY(30px);opacity:0;pointer-events:none;background:#14281e;color:#fff;padding:12px 17px;border-radius:10px;box-shadow:var(--shadow);transition:.2s}.toast.show{transform:none;opacity:1}.hint{padding:10px 13px;background:#f8f4e8;border-left:3px solid var(--accent);font-size:13px}@media(max-width:800px){.app{grid-template-columns:1fr}.sidebar{position:static;height:auto;flex-direction:row;align-items:center;gap:8px;padding:12px}.brand{padding:0;margin-right:auto}.brand div{display:none}.sidebar nav{display:flex}.logout{margin:0}.topbar{padding:0 20px}.panel{padding:24px 18px}.operator{display:none}}@media(max-width:560px){.nav{font-size:0;width:44px}.nav::first-letter{font-size:16px}.toolbar{align-items:flex-start}.form-grid{display:block}.span-2{grid-column:auto}.inline-form{grid-template-columns:1fr}.course-grid{grid-template-columns:1fr}}