:root{--bg:#061226;--panel:#0b1d38;--panel-2:#102947;--line:rgba(130,190,255,.19);--text:#edf7ff;--muted:#8fa8c3;--blue:#39a9ff;--cyan:#42e8e0;--orange:#ff9d54;--danger:#ff6689;--shadow:0 24px 70px rgba(0,4,14,.42)}
*{box-sizing:border-box}html{color-scheme:dark}body{min-height:100vh;margin:0;background:radial-gradient(circle at 85% 3%,rgba(23,108,192,.24),transparent 32%),radial-gradient(circle at 8% 90%,rgba(27,218,208,.1),transparent 28%),var(--bg);color:var(--text);font-family:"PingFang SC","Microsoft YaHei",system-ui,sans-serif}.admin-grid{position:fixed;inset:0;width:100%;height:100%;opacity:.34;pointer-events:none;background-image:linear-gradient(rgba(77,150,222,.055) 1px,transparent 1px),linear-gradient(90deg,rgba(77,150,222,.055) 1px,transparent 1px);background-size:42px 42px;mask-image:linear-gradient(to bottom,black,transparent 90%)}button,input,select{font:inherit}.admin-header{position:relative;z-index:2;display:flex;align-items:center;justify-content:space-between;width:min(1440px,calc(100% - 48px));height:88px;margin:18px auto 0;padding:0 24px;border:1px solid var(--line);border-radius:24px;background:rgba(7,22,44,.78);box-shadow:var(--shadow);backdrop-filter:blur(22px)}.admin-brand{display:flex;align-items:center;gap:13px;color:inherit;text-decoration:none}.admin-brand img{width:54px;height:54px;border-radius:50%;background:white;box-shadow:0 0 28px rgba(57,169,255,.38)}.admin-brand span{display:grid;gap:2px}.admin-brand b{font-size:19px;letter-spacing:.08em}.admin-brand small{color:#7fa6cc;font-size:10px;letter-spacing:.18em}.back-site{padding:12px 16px;border:1px solid var(--line);border-radius:999px;color:#bfe6ff;text-decoration:none}.back-site span{color:var(--cyan)}.admin-main{position:relative;z-index:1;width:min(1380px,calc(100% - 64px));margin:58px auto 80px}.login-panel{display:grid;grid-template-columns:.8fr 1.2fr;min-height:470px;overflow:hidden;border:1px solid var(--line);border-radius:32px;background:rgba(9,27,53,.82);box-shadow:var(--shadow)}.login-visual{position:relative;display:grid;place-items:center;overflow:hidden;background:radial-gradient(circle,rgba(57,169,255,.24),transparent 54%),linear-gradient(145deg,#0d2e54,#081a33)}.login-visual:before,.login-visual:after,.login-visual span{content:"";position:absolute;width:310px;height:310px;border:1px solid rgba(66,232,224,.34);border-radius:50%;animation:spin 18s linear infinite}.login-visual:after{width:224px;height:224px;border-style:dashed;animation-direction:reverse;animation-duration:12s}.login-visual span{width:390px;height:130px;border-color:rgba(57,169,255,.25);transform:rotate(-16deg)}.login-visual b{position:relative;font-size:clamp(50px,7vw,92px);letter-spacing:-.06em;text-shadow:0 0 38px rgba(57,169,255,.7)}.login-visual i{position:absolute;bottom:72px;color:var(--cyan);font-style:normal;font-size:12px;letter-spacing:.24em}.login-copy{align-self:center;padding:62px}.eyebrow{margin:0 0 12px;color:var(--cyan);font-size:12px;font-weight:800;letter-spacing:.2em}.login-copy h1,.dashboard-head h1{margin:0;font-size:clamp(36px,4.3vw,64px);letter-spacing:-.06em}.login-copy>p:not(.eyebrow),.dashboard-head>div>p:last-child{max-width:720px;color:var(--muted);font-size:16px;line-height:1.75}.login-copy form{margin-top:38px}.login-copy label{display:block;margin-bottom:10px;color:#cae6ff;font-weight:700}.key-row{display:grid;grid-template-columns:1fr auto;gap:12px}.key-row input,.form-grid input,.form-grid select,.admin-search input{min-width:0;border:1px solid var(--line);outline:0;background:#06162b;color:var(--text)}.key-row input{height:54px;padding:0 18px;border-radius:14px}.key-row input:focus,.form-grid input:focus,.form-grid select:focus,.admin-search:focus-within{border-color:var(--blue);box-shadow:0 0 0 3px rgba(57,169,255,.12)}.key-row button{border:0;border-radius:14px;padding:0 24px;background:linear-gradient(135deg,#1177e6,#27c7d9);color:white;font-weight:800;cursor:pointer}.form-message{min-height:24px;margin:10px 0 0!important;color:var(--danger)!important;font-size:14px!important}.dashboard[hidden],.login-panel[hidden]{display:none}.dashboard-head{display:flex;align-items:flex-end;justify-content:space-between;gap:28px}.head-actions{display:flex;gap:12px;flex-shrink:0}.button{min-height:46px;border:1px solid transparent;border-radius:13px;padding:0 18px;color:white;font-weight:800;cursor:pointer}.button:disabled{cursor:wait;opacity:.58}.button-primary{background:linear-gradient(135deg,#126ce0,#25c8d7);box-shadow:0 10px 28px rgba(20,131,218,.25)}.button-ghost{border-color:var(--line);background:#0b203d;color:#bcd9f1}.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin:34px 0}.stats article{position:relative;overflow:hidden;padding:22px 24px;border:1px solid var(--line);border-radius:20px;background:linear-gradient(145deg,rgba(16,43,76,.94),rgba(7,25,48,.92))}.stats article:after{content:"";position:absolute;right:-24px;bottom:-42px;width:110px;height:110px;border:1px solid rgba(57,169,255,.25);border-radius:50%;box-shadow:0 0 0 17px rgba(57,169,255,.04)}.stats span,.stats small{display:block;color:var(--muted);font-size:10px;letter-spacing:.14em}.stats b{display:block;margin:7px 0;font-size:38px}.toolbar{display:flex;align-items:center;justify-content:space-between;gap:20px;margin:0 0 18px;padding:12px;border:1px solid var(--line);border-radius:18px;background:rgba(9,28,55,.74)}.course-switch{display:flex;gap:6px}.course-switch button{border:0;border-radius:10px;padding:11px 16px;background:transparent;color:var(--muted);cursor:pointer}.course-switch button.active{background:#143a67;color:white}.admin-search{display:flex;align-items:center;gap:8px;width:min(360px,100%);padding:0 14px;border:1px solid var(--line);border-radius:12px;background:#06162b}.admin-search span{color:var(--cyan);font-size:20px}.admin-search input{width:100%;height:42px;padding:0;border:0;background:transparent}.notice{margin:16px 0;padding:14px 18px;border:1px solid rgba(66,232,224,.28);border-radius:13px;background:rgba(42,202,194,.1);color:#bbfffb}.notice.error{border-color:rgba(255,102,137,.34);background:rgba(255,102,137,.1);color:#ffd0dc}.lesson-list{display:grid;gap:12px}.lesson-row{display:grid;grid-template-columns:92px minmax(0,1fr) auto;align-items:center;gap:20px;padding:19px 20px;border:1px solid var(--line);border-radius:18px;background:rgba(9,29,56,.86);transition:.2s}.lesson-row:hover{border-color:rgba(57,169,255,.42);transform:translateY(-1px)}.lesson-code{display:grid;place-items:center;min-height:68px;border:1px solid rgba(57,169,255,.24);border-radius:14px;background:#0a2343;color:#9cdbff;font-size:21px;font-weight:900}.lesson-copy{min-width:0}.lesson-copy p{margin:0 0 5px;color:var(--cyan);font-size:11px;font-weight:800;letter-spacing:.1em}.lesson-copy h3{margin:0;font-size:21px}.lesson-copy span{display:block;overflow:hidden;margin-top:5px;color:var(--muted);font-size:14px;text-overflow:ellipsis;white-space:nowrap}.lesson-actions{display:flex;gap:7px}.lesson-actions button,.lesson-actions a{display:inline-flex;align-items:center;justify-content:center;min-height:40px;border:1px solid var(--line);border-radius:10px;padding:0 12px;background:#0c2545;color:#cfe9ff;text-decoration:none;cursor:pointer}.lesson-actions .danger{color:#ffb2c3}.source-tag{display:inline-flex!important;width:max-content;margin-left:8px!important;padding:3px 7px;border-radius:999px;background:rgba(255,157,84,.13);color:#ffbd87!important;font-size:9px!important}.recycle{margin-top:30px;border:1px solid var(--line);border-radius:18px;background:rgba(6,21,42,.76)}.recycle summary{display:flex;align-items:center;gap:10px;padding:18px 20px;cursor:pointer}.recycle summary b{display:grid;place-items:center;min-width:28px;height:28px;border-radius:999px;background:#173a62}.recycle summary small{margin-left:auto;color:var(--muted)}.deleted-list{display:grid;gap:8px;padding:0 14px 14px}.deleted-row{display:flex;align-items:center;gap:16px;padding:14px;border-radius:12px;background:#0b203b;color:var(--muted)}.deleted-row b{color:#d8eaff}.deleted-row button{margin-left:auto;border:1px solid var(--line);border-radius:9px;padding:8px 13px;background:#123255;color:#bffaf6;cursor:pointer}.empty{padding:40px;text-align:center;border:1px dashed var(--line);border-radius:18px;color:var(--muted)}dialog{width:min(850px,calc(100% - 32px));max-height:90vh;padding:0;border:1px solid rgba(94,174,244,.35);border-radius:24px;background:#091c36;color:var(--text);box-shadow:0 30px 100px #000}dialog::backdrop{background:rgba(0,7,18,.77);backdrop-filter:blur(8px)}#lesson-form{padding:26px}.dialog-head{display:flex;align-items:flex-start;justify-content:space-between}.dialog-head h2{margin:0;font-size:31px}.icon-button{width:40px;height:40px;border:1px solid var(--line);border-radius:50%;background:#102846;color:white;font-size:26px;cursor:pointer}.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:25px}.form-grid label{display:grid;gap:8px;color:#cce6fb;font-size:14px;font-weight:700}.form-grid .wide{grid-column:1/-1}.form-grid input,.form-grid select{height:46px;padding:0 13px;border-radius:11px}.form-grid small,.file-field span{color:var(--muted);font-size:12px;font-weight:400}.file-field{padding:16px;border:1px dashed rgba(66,232,224,.3);border-radius:13px;background:rgba(66,232,224,.04)}.file-field input{height:auto;padding:10px;background:transparent}.dialog-actions{display:flex;justify-content:flex-end;gap:10px;margin-top:26px}@keyframes spin{to{transform:rotate(360deg)}}@media(max-width:900px){.admin-main{width:min(100% - 32px,1380px);margin-top:30px}.login-panel{grid-template-columns:1fr}.login-visual{min-height:220px}.login-copy{padding:34px}.dashboard-head,.toolbar{align-items:stretch;flex-direction:column}.stats{grid-template-columns:1fr 1fr}.lesson-row{grid-template-columns:68px 1fr}.lesson-actions{grid-column:1/-1}.admin-search{width:100%}}@media(max-width:560px){.admin-header{width:calc(100% - 20px);padding:0 14px}.admin-brand small,.back-site span{display:none}.admin-brand img{width:44px;height:44px}.back-site{padding:10px}.admin-main{width:calc(100% - 20px)}.login-copy{padding:26px 20px}.key-row{grid-template-columns:1fr}.key-row button{height:50px}.stats{grid-template-columns:1fr 1fr}.stats article{padding:18px}.course-switch{display:grid;grid-template-columns:repeat(3,1fr)}.course-switch button{padding:10px 7px}.lesson-row{padding:14px;gap:12px}.lesson-actions{display:grid;grid-template-columns:repeat(2,1fr)}.form-grid{grid-template-columns:1fr}.form-grid .wide{grid-column:auto}}