:root{--ink:#203a35;--muted:#7b8780;--green:#23624e;--line:#e2e6df;--paper:#f5f6f0;--soft:#eaf0e7;--white:#fff;--orange:#a16a39}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font-family:"PingFang SC","Microsoft YaHei",sans-serif;font-size:15px;-webkit-font-smoothing:antialiased}a{color:inherit;text-decoration:none}button,input,select{font:inherit}button,a,input,select{outline-offset:5px}button{cursor:pointer}svg{display:block}button{color:inherit}button:disabled{cursor:default}.shell{max-width:1280px;margin:auto}.topbar{height:100px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line);margin:0 64px}.brand{display:flex;align-items:center;gap:13px;font-size:22px;font-weight:650;letter-spacing:1px}.brand small{font-size:15px;font-weight:450;letter-spacing:0;color:#69786f;border-left:1px solid #cdd4cb;padding-left:18px;margin-left:5px}.mark{background:var(--green);color:white;width:40px;height:40px;border-radius:12px;display:grid;place-items:center}.topnav{display:flex;align-items:center;gap:27px;font-size:14px;color:#6e7b73}.topnav .active{color:var(--green)}.icontext{display:flex;align-items:center;gap:8px}.tiny{font-size:12px;letter-spacing:1px;color:var(--muted)}.eyebrow{font-size:12px;letter-spacing:2px;font-weight:600;color:var(--green);margin-bottom:13px}.muted{color:var(--muted)}h1,h2,h3,p{margin:0}h1{font-size:40px;letter-spacing:-1px;font-weight:600;line-height:1.4}h2{font-size:24px;font-weight:600}h3{font-size:18px;font-weight:600}.lede{font-size:15px;line-height:1.8;color:#7b8780;margin-top:13px}.button{border:0;border-radius:10px;background:var(--green);color:#fff;padding:15px 24px;display:inline-flex;align-items:center;justify-content:center;gap:14px;font-size:16px;font-weight:500}.button.light{color:var(--green);background:#edf2eb;border:1px solid #dce6da}.button.outline{color:var(--ink);background:white;border:1px solid var(--line)}.tag{font-size:12px;font-weight:500;border:1px solid #d6e3d4;color:var(--green);padding:5px 10px;border-radius:5px;background:#f5f8f1;white-space:nowrap}.tag.gray{color:#9ba39b;background:#f5f6f2;border-color:#e6e9e1}.tag.sand{color:#9a6937;background:#fbf4e9;border-color:#eddfc6}.foot{display:flex;justify-content:space-between;align-items:center;font-size:12px;color:#919b92;padding:25px 0;margin-top:26px;border-top:1px solid var(--line)}.breadcrumb{font-size:13px;color:#879187;display:flex;align-items:center;gap:12px}.breadcrumb b{font-weight:500;color:var(--ink)}.page-body{padding:31px 64px 20px}.heading-row{display:flex;align-items:end;justify-content:space-between;margin-top:29px}.chapter-label{display:flex;align-items:center;gap:9px}.dot{width:6px;height:6px;background:#719479;display:inline-block;border-radius:50%}.preview-note{display:flex;gap:8px;align-items:center;font-size:12px;color:#8c948b}
/* 密码入口 */
.login-main{display:grid;grid-template-columns:1.2fr 1fr;align-items:center;min-height:777px;padding:38px 116px 56px;gap:80px;max-width:1440px;margin:auto}.login-intro h1{font-size:53px;line-height:1.35;font-weight:550;letter-spacing:0}.login-intro .lede{font-size:16px;line-height:1.9;margin-top:22px}.login-intro .eyebrow{margin-bottom:25px}.login-art{height:274px;margin-top:32px;position:relative;border-bottom:1px solid #dce3d8}.login-art>svg{width:100%;height:100%}.art-label{position:absolute;font-size:12px;color:#96a18f;bottom:14px;left:0;letter-spacing:2px}.login-card{padding:42px 40px;background:#fff;border:1px solid #e0e5da;border-radius:22px;box-shadow:0 16px 55px #223d2a06;max-width:426px;position:relative}.login-card .lock{margin-bottom:28px;background:#eff4eb;color:var(--green);width:48px;height:48px;display:grid;place-items:center;border-radius:14px}.login-card h2{font-size:27px;font-weight:600}.login-card p{font-size:14px;line-height:1.8;color:#8a938b;margin-top:10px}.login-card label{font-size:14px;display:block;margin-top:34px;margin-bottom:12px}.password-field{display:flex;align-items:center;gap:8px;border:1px solid #cfdbcd;background:#fbfcf9;border-radius:9px;height:55px;padding:0 15px}.password-field input{min-width:0;border:0;background:none;width:100%;color:var(--ink);font-size:22px;letter-spacing:6px;outline:none}.eye{border:0;background:none;color:#92a18f;padding:5px}.login-card .button{width:100%;margin-top:20px;height:54px}.safe-note{border-top:1px solid var(--line);padding-top:20px;margin-top:27px;font-size:12px;color:#92998f;display:flex;align-items:center;gap:8px}.login-foot{margin:0 64px;display:flex;justify-content:space-between;padding:25px 0;border-top:1px solid var(--line);font-size:12px;color:#959d93}.error{font-size:12px;color:#a75e40;min-height:17px;margin-top:7px}
/* 年级主页 */
.home-intro{display:flex;align-items:center;justify-content:space-between;padding:36px 0 29px}.home-intro h1{font-size:38px}.home-stamp{display:flex;align-items:center;gap:15px;border-left:1px solid #d6dfd1;padding:14px 0 14px 28px}.home-stamp .num{font-family:Georgia,serif;font-size:48px;font-weight:400;line-height:1}.grade-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:17px;margin-top:13px}.grade-card{border:1px solid #e1e5db;background:#fafbf7;border-radius:15px;position:relative;min-height:171px;padding:27px 29px;overflow:hidden}.grade-card .grade-num{font-family:Georgia,serif;font-size:68px;position:absolute;right:30px;top:24px;color:#e4e8de;font-weight:400;line-height:1.2}.grade-card h2{font-size:24px;position:relative;margin-bottom:13px}.grade-card .grade-bottom{display:flex;align-items:center;justify-content:space-between;margin-top:23px;font-size:12px;color:#9da498}.grade-card.active{background:var(--green);color:white;border:1px solid var(--green);box-shadow:0 8px 20px #225d4912}.grade-card.active .grade-num{color:#4e816c}.grade-card.active .grade-bottom{color:#d5e5d7}.grade-card.active .tag{color:#e9f3df;background:#38715c;border-color:#628d73}.grade-card.active:hover{background:#1d5543}.home-bottom{background:#eef1e8;border-radius:10px;margin-top:25px;padding:18px 22px;display:flex;align-items:center;justify-content:space-between;color:#71806d;font-size:13px}
/* 课程列表 */
.courses-top{display:flex;align-items:end;justify-content:space-between;padding:27px 0 24px}.statline{display:flex;gap:32px;align-items:center;font-size:13px;color:#8a9588}.statline b{font-size:29px;font-family:Georgia,serif;color:var(--ink);font-weight:400;margin-right:6px}.seasons-nav{display:flex;gap:9px}.seasons-nav a{padding:10px 22px;border:1px solid #dce4d7;background:#fff;border-radius:8px;font-size:14px}.seasons-nav a:first-child{background:#e7efdf;color:var(--green);border-color:#d2e0c8}.season-block{margin-top:21px}.season-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:13px}.season-head h2{font-size:18px;display:flex;align-items:center;gap:10px}.season-symbol{font-size:12px;width:26px;height:26px;background:#f2e8ce;color:#98702c;display:grid;place-items:center;border-radius:7px}.season-block:nth-of-type(2) .season-symbol{background:#f3e5d6;color:#a1703d}.season-block:nth-of-type(3) .season-symbol{background:#e1eced;color:#629394}.season-block:nth-of-type(4) .season-symbol{background:#e8edda;color:#7d9551}.season-head span.count{font-size:12px;color:#8d968b;font-weight:400;letter-spacing:0}.lesson-grid{display:grid;grid-template-columns:repeat(8,minmax(0,1fr));gap:10px}.lesson-card{background:white;border:1px solid #e3e7de;border-radius:10px;height:71px;padding:13px 15px;position:relative;display:flex;flex-direction:column;gap:6px;justify-content:center}.lesson-card strong{font-size:14px;font-weight:500}.lesson-card small{font-size:11px;color:#a5ac9f}.lesson-card.active{background:var(--green);border-color:var(--green);color:white;box-shadow:0 3px 9px #235e4912}.lesson-card.active small{color:#d7e8c9;font-size:12px}.lesson-card.active .arrow{position:absolute;right:11px;top:17px}.lesson-note{font-size:12px;color:#94a08d;margin-top:22px;display:flex;align-items:center;gap:8px}.courses .foot{margin-top:21px;padding-top:20px}.courses .page-body{padding-top:23px}.courses h1{font-size:34px}
/* 课程内容页 */
.lesson-toolbar{display:flex;align-items:center;justify-content:space-between;padding:25px 0}.lesson-toolbar h1{font-size:27px;margin-top:8px;letter-spacing:0}.lesson-toolbar .actions{display:flex;gap:10px}.lesson-toolbar .button{padding:12px 16px;font-size:14px}.viewer{border:1px solid #dce4d6;background:#fff;border-radius:15px;overflow:hidden}.viewer-top{height:52px;border-bottom:1px solid #e5e9df;background:#fafbf7;display:flex;align-items:center;justify-content:space-between;padding:0 25px;font-size:12px;color:#8a9483}.viewer-content{min-height:590px;display:grid;grid-template-columns:1fr 330px;gap:25px;padding:41px 38px 35px}.diagram-side h2{font-size:29px;margin-top:9px}.diagram-side .lede{font-size:14px;margin-top:12px}.diagram{height:320px;width:100%;margin-top:23px}.diagram text{font-family:"PingFang SC",sans-serif}.control-bar{display:flex;align-items:center;gap:17px;background:#f6f8f2;border:1px solid #e7ebdf;padding:15px 20px;border-radius:9px;font-size:13px}.control-bar input{accent-color:var(--green);flex:1;min-width:50px}.point-pill{width:25px;height:25px;border-radius:50%;background:#dce7d4;color:#54724d;display:grid;place-items:center}.right-panel{background:#f5f7ef;border:1px solid #e6ebdc;border-radius:13px;padding:25px;align-self:stretch;display:flex;flex-direction:column}.right-panel .tag{align-self:start;margin-bottom:22px}.right-panel h3{font-size:20px;line-height:1.6}.ratio-row{display:flex;gap:12px;align-items:center;justify-content:center;margin:27px 0;font-family:Georgia,serif;font-size:37px;font-weight:400;color:var(--green)}.ratio-row .ratio{padding:14px;background:#fff;border-radius:10px;font-size:28px}.right-panel p{font-size:14px;line-height:1.9;color:#7a8771}.formula{background:#fff;border:1px solid #e3e9d9;border-radius:8px;padding:19px 13px;text-align:center;line-height:2;margin-top:21px;font-size:15px}.viewer-footer{display:flex;justify-content:space-between;align-items:center;font-size:12px;color:#9ca494;margin-top:20px}
/* 后台 */
.admin-layout{display:grid;grid-template-columns:222px 1fr;min-height:1000px}.sidebar{background:#eff2e9;border-right:1px solid #dce2d5;padding:34px 24px;display:flex;flex-direction:column}.sidebar .brand{font-size:18px;gap:10px;letter-spacing:0}.sidebar .mark{width:34px;height:34px;border-radius:10px}.sidebar-sub{font-size:12px;color:#97a28e;margin-top:12px;padding-left:44px}.sidebar .nav-label{font-size:11px;color:#99a38f;letter-spacing:1px;margin-top:57px;margin-bottom:13px}.side-item{display:flex;align-items:center;gap:10px;font-size:14px;padding:14px 13px;color:#7f8a75;margin-bottom:7px;border-radius:9px}.side-item.active{background:#dfe9d6;color:var(--green);font-weight:600}.sidebar .back{margin-top:auto;border-top:1px solid #d8e0ce;padding:21px 0 3px;font-size:13px;color:#7e8b72;display:flex;gap:8px;align-items:center}.admin-main{padding:0 44px}.admin-top{height:97px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid #dfe5d8;font-size:13px;color:#8b9683}.avatar{width:28px;height:28px;border-radius:50%;display:grid;place-items:center;background:#e0e8d7;font-size:11px;color:#647956}.admin-title{display:flex;align-items:center;justify-content:space-between;margin-top:30px}.admin-title h1{font-size:31px}.admin-sub{margin-top:9px;font-size:13px;color:#8a9582}.admin-stats{display:flex;gap:10px;margin-top:24px}.admin-stat{background:#f0f3e9;border:1px solid #e3e8da;border-radius:9px;padding:16px 21px;flex:1;display:flex;align-items:center;justify-content:space-between}.admin-stat span{font-size:12px;color:#8c9781}.admin-stat b{font-family:Georgia,serif;font-size:27px;font-weight:400}.admin-card{background:white;border:1px solid #e0e6d9;border-radius:13px;padding:25px 28px;margin-top:21px}.admin-card h2{font-size:18px;margin-bottom:20px}.admin-form{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.field label{display:block;font-size:12px;color:#85917c;margin-bottom:9px}.field select,.field input{width:100%;height:44px;padding:0 13px;color:#4c6045;border:1px solid #dce4d3;border-radius:7px;background:#fbfcf9;font-size:14px}.title-field{margin-top:16px}.dropzone{border:1px dashed #bbcca9;background:#f9fbf5;border-radius:9px;padding:23px;display:flex;align-items:center;justify-content:center;gap:17px;margin-top:20px;position:relative;cursor:pointer}.dropzone .upload-icon{width:45px;height:45px;border:1px solid #dce5d0;background:#fff;border-radius:10px;display:grid;place-items:center;color:#668454}.dropzone p{font-size:14px;color:#617552}.dropzone small{font-size:11px;color:#a3ad98;display:block;margin-top:7px}.dropzone input{position:absolute;opacity:0;inset:0;cursor:pointer;width:100%;height:100%}.form-bottom{display:flex;align-items:center;justify-content:space-between;margin-top:20px;font-size:11px;color:#929e87}.form-bottom .button{padding:12px 20px;font-size:14px}.form-bottom .group{display:flex;gap:10px}.admin-table{padding:22px 28px;margin-top:20px;background:#fff;border:1px solid #e0e6d9;border-radius:13px}.table-title{display:flex;align-items:center;justify-content:space-between;margin-bottom:15px}.table-title h2{font-size:18px}.table-title span{font-size:11px;color:#929e85}table{width:100%;border-collapse:collapse;text-align:left;font-size:13px}th{font-size:11px;color:#9aa68b;background:#f7f9f2;font-weight:400;padding:12px 13px}td{border-bottom:1px solid #edf0e6;padding:15px 13px;color:#7d8a6d}td:first-child{color:#4e6342}td:last-child{color:var(--green)}.admin-footer{display:flex;justify-content:space-between;font-size:11px;color:#99a38d;padding:22px 0}.demo-toast{position:fixed;bottom:30px;left:50%;transform:translateX(-50%);background:#234d3d;color:white;font-size:14px;padding:15px 23px;border-radius:11px;box-shadow:0 8px 30px #234d3d30;z-index:99}
@media(min-width:1500px){.topbar,.login-foot{max-width:1312px;margin-left:auto;margin-right:auto}.page-body{max-width:1440px;margin:auto}}@media(max-width:900px){.topbar{margin:0 25px}.topnav .muted{display:none}.brand small{display:none}.page-body{padding:25px}.login-main{padding:40px 25px;gap:30px;grid-template-columns:1fr;min-height:0}.login-intro{display:none}.login-card{margin:20px auto 50px;width:100%}.login-foot{margin:0 25px}.grade-grid{grid-template-columns:repeat(2,1fr)}.home-stamp{display:none}.home-intro h1{font-size:30px}.lesson-grid{grid-template-columns:repeat(4,minmax(0,1fr))}.courses-top{align-items:start}.statline{display:none}.viewer-content{grid-template-columns:1fr;padding:25px}.admin-layout{grid-template-columns:1fr}.sidebar{display:none}.admin-main{padding:0 23px}.topnav{gap:13px}.viewer-top{padding:0 15px}.lesson-toolbar{gap:15px}.lesson-toolbar .actions{display:none}.home-bottom{gap:20px}.foot{gap:20px}.admin-form{gap:8px}.form-bottom{gap:15px}.admin-title h1{font-size:28px}.seasons-nav a{padding:10px 13px}.lesson-card{padding:13px 10px}.diagram{height:260px}.grade-card{padding:25px 20px}.grade-card .grade-num{right:16px}.admin-stat{padding:15px}.admin-table{overflow:auto}.admin-card{padding:22px}.preview-note{display:none}}@media(max-width:500px){.topnav{font-size:12px}.brand{font-size:18px}.grade-card .grade-num{font-size:52px;top:35px}.grade-card h2{font-size:21px}.grade-card .grade-bottom{font-size:11px}.home-bottom span:last-child{display:none}.grade-grid{gap:10px}.lesson-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.courses-top{display:block}.seasons-nav{margin-top:20px}.admin-stat{gap:8px;flex-direction:column}.admin-title .tag{display:none}.form-bottom{align-items:start;flex-direction:column}.admin-form{grid-template-columns:1fr}.login-foot span:last-child{display:none}}

.lesson-card small{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.admin-exit{border:0;background:none;cursor:pointer;font:inherit;color:#7f8a75}.upload-status{font-size:13px;line-height:1.8;color:#23624e;min-height:10px;margin-top:12px}.filename{max-width:260px;white-space:nowrap;text-overflow:ellipsis;overflow:hidden}.table-actions{display:flex;gap:14px;white-space:nowrap;align-items:center}.link-button{border:0;background:none;color:#23624e;font:inherit;padding:0;cursor:pointer}.preview-dialog{width:96vw;height:94vh;border:1px solid #d7e0d0;border-radius:14px;padding:0;background:white;max-width:none;max-height:none}.preview-dialog::backdrop{background:#173c2ccc}.preview-bar{height:70px;padding:15px 24px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid #e1e7d9}.preview-bar .button{padding:10px 15px;font-size:14px}.preview-dialog iframe{border:0;width:100%;height:calc(100% - 74px)}.dragging{border-color:#23624e;background:#edf3e5}.load-error{padding:100px 30px;text-align:center}.load-error p{margin:20px}.button:disabled{opacity:.6;cursor:wait}.table-scroll{overflow-x:auto}td:first-child{white-space:nowrap}.admin-table{max-width:100%}.admin-main{min-width:0}