:root{--pku-red:#94070a;--pku-red-dark:#6f0507;--pku-red-light:#c0392b}*{box-sizing:border-box}html,body,#root{height:100%;margin:0;padding:0}body{color:#333;background:#f4f5f7;font-family:Arial,Helvetica,PingFang SC,Microsoft YaHei,sans-serif;font-size:14px;line-height:1.5}.app-container{width:100%;max-width:1200px;margin:0 auto;padding:0 24px}.app-header{z-index:100;border-top:3px solid var(--pku-red);background:#fff;padding:0;position:sticky;top:0;box-shadow:0 1px #0000000f,0 2px 12px #0000000a}.app-header-inner{align-items:center;gap:24px;height:61px;display:flex}.app-brand{white-space:nowrap;color:var(--pku-red);align-items:center;gap:10px;font-size:18px;font-weight:700;display:flex}.app-brand:hover{color:var(--pku-red)}.app-brand-mark{background:var(--pku-red);color:#fff;letter-spacing:.5px;border-radius:9px;justify-content:center;align-items:center;width:34px;height:34px;font-size:15px;display:inline-flex;box-shadow:0 2px 8px #94070a4d}.app-nav{background:0 0;border-bottom:none;flex:1;min-width:0;font-weight:500}.app-header-actions{margin-left:auto}.app-user{color:#333;border-radius:8px;align-items:center;gap:8px;padding:4px 8px;transition:background .2s;display:inline-flex}.app-user:hover{color:var(--pku-red);background:#0000000a}.app-user-name{font-weight:500}.app-content{padding:24px 0 40px}.app-footer{text-align:center;color:#999;font-size:12px;line-height:16px}.hero{background:var(--pku-red);color:#fff;border-radius:18px;margin-bottom:8px;padding:48px 44px;position:relative;overflow:hidden}.hero:before{content:"";background:#ffffff0f;border-radius:50%;width:300px;height:300px;position:absolute;bottom:-90px;right:-40px}.hero:after{content:"";background:#ffffff14;border-radius:50%;width:240px;height:240px;position:absolute;top:-60px;right:-60px}.hero-inner{z-index:1;align-items:center;gap:40px;display:flex;position:relative}.hero-content{flex:1;min-width:0}.hero-eyebrow{letter-spacing:.5px;color:#ffffffd9;background:#ffffff24;border:1px solid #ffffff38;border-radius:999px;margin-bottom:14px;padding:3px 12px;font-size:12px;line-height:16px;display:inline-block}.hero-title{color:#fff!important;margin-bottom:8px!important;font-size:24px!important;font-weight:700!important;line-height:32px!important}.hero-greeting{color:#ffffffeb;margin-bottom:6px;font-size:14px}.hero-sub{max-width:640px;font-size:14px;line-height:22px;color:#ffffffe6!important;margin-bottom:0!important}.hero-stats{margin-top:24px}.hero-tags{flex-wrap:wrap;gap:8px;margin-top:22px;display:flex}.hero-tag{color:#fff;background:#ffffff24;border:1px solid #ffffff38;border-radius:999px;padding:4px 12px;font-size:12px}.hero-panel{background:#ffffff1a;border:1px solid #ffffff2e;border-radius:14px;flex-direction:column;flex:0 0 320px;gap:14px;padding:22px;display:flex}.hero-panel-item{color:#fffffff2;align-items:flex-start;gap:10px;font-size:14px;line-height:1.6;display:flex}.hero-panel-item .anticon{color:#fff;opacity:.9;flex:none;margin-top:3px}@media (width<=860px){.hero{padding:36px 28px}.hero-inner{flex-direction:column;align-items:stretch;gap:24px}.hero-panel{flex:none}}.quick-links{margin-bottom:4px}.quick-card{text-align:center;border:1px solid #0000;height:100%;transition:transform .18s,box-shadow .18s,border-color .18s;position:relative}.quick-card .ant-card-body{padding:22px 16px}.quick-card:hover{border-color:#94070a2e;transform:translateY(-4px);box-shadow:0 12px 26px #94070a29}.quick-icon-wrap{background:#94070a14;border-radius:15px;justify-content:center;align-items:center;width:54px;height:54px;margin:0 auto 14px;transition:background .18s;display:flex}.quick-card:hover .quick-icon-wrap{background:#94070a24}.quick-icon{color:var(--pku-red);font-size:26px;line-height:1}.quick-badge{background:var(--pku-red);color:#fff;letter-spacing:.5px;border-radius:8px;padding:1px 6px;font-size:10px;font-weight:700;position:absolute;top:8px;right:8px}.quick-title{color:#333;margin-bottom:4px;font-size:16px;font-weight:700;line-height:22px}.quick-desc{color:#999;font-size:12px;line-height:16px}.section-head{border-left:3px solid var(--pku-red);margin:30px 0 16px;padding-left:12px}.section-head h1.ant-typography,.section-head h2.ant-typography,.section-head h3.ant-typography,.section-head h4.ant-typography,.section-head h5.ant-typography{color:#333;font-size:18px;font-weight:700;line-height:24px}.section-head .ant-typography-secondary{color:#999;font-size:12px;line-height:16px}.feature-card{height:100%;transition:transform .18s,box-shadow .18s}.feature-card:hover{transform:translateY(-3px);box-shadow:0 12px 26px #00000014}.feature-card .ant-card-body{align-items:flex-start;gap:16px;padding:22px;display:flex}.feature-icon{color:#fff;background:var(--pku-red);border-radius:12px;flex:none;justify-content:center;align-items:center;width:48px;height:48px;font-size:22px;display:flex}.feature-title{color:#333;align-items:center;gap:8px;margin-bottom:6px;font-size:16px;font-weight:700;line-height:22px;display:flex}.feature-index{color:var(--pku-red);font-family:Arial,Helvetica,sans-serif;font-size:14px;font-weight:700}.feature-desc{color:#666;font-size:14px;line-height:20px}.sample-block{white-space:pre-wrap;word-break:break-all;background:#f6f7f9;border:1px solid #eceef1;border-radius:8px;margin:4px 0;padding:10px 14px;font-family:SFMono-Regular,Consolas,Liberation Mono,Menlo,monospace;font-size:13px;line-height:1.6}.ant-card{box-shadow:0 1px 2px #0000000a,0 4px 16px #0000000a}.ant-card-head-title{color:#333;font-size:16px;font-weight:700;line-height:22px}.lecture-card{border:1px solid #0000;height:100%;transition:transform .18s,box-shadow .18s,border-color .18s}.lecture-card:hover{border-color:#94070a29;transform:translateY(-3px);box-shadow:0 12px 26px #94070a24}.lecture-card-head{align-items:center;gap:10px;margin-bottom:10px;display:flex}.lecture-order{color:var(--pku-red);font-size:13px;font-weight:700}.lecture-duration{color:#999;margin-left:auto;font-size:12px;line-height:16px}.lecture-card-title{color:#333;margin-bottom:8px;font-size:18px;font-weight:700;line-height:24px}.lecture-card-summary{font-size:14px;line-height:20px;color:#666!important;margin-bottom:12px!important}.lecture-card-foot{color:var(--pku-red);font-size:12px;line-height:16px;transition:color .18s}.lecture-card:hover .lecture-card-foot{color:var(--pku-red)}.lecture-detail-head .ant-typography{margin-bottom:0}.lec-section{margin-bottom:8px;scroll-margin-top:80px}.lec-section-title{color:#333!important;margin-top:4px!important;margin-bottom:12px!important;font-size:16px!important;font-weight:700!important;line-height:22px!important}.lec-p{font-size:14px;color:#333!important;margin-bottom:12px!important;line-height:1.9!important}.lec-sub{color:#333;margin:6px 0 8px;font-size:14px;font-weight:700}.lec-list{margin:0 0 14px;padding-left:22px}.lec-list li{color:#333;margin-bottom:4px;font-size:14px;line-height:1.9}.lec-code{word-break:normal;overflow-x:auto;margin:4px 0 16px!important}.lec-formula{text-align:center;color:var(--pku-red-dark);background:#fbf3f3;border:1px dashed #94070a47;border-radius:8px;margin:4px 0 16px;padding:12px 16px;font-family:SFMono-Regular,Consolas,Liberation Mono,Menlo,monospace;font-size:14px}.lec-note{border-left:3px solid var(--pku-red);color:#666;background:#f6f7f9;border-radius:6px;gap:10px;margin:4px 0 16px;padding:12px 14px;font-size:14px;line-height:1.8;display:flex}.lec-note-icon{color:var(--pku-red);flex:none;margin-top:3px}.lec-note-title{color:#333;margin-bottom:2px;font-weight:700}.lecture-side{position:sticky;top:84px}.lec-outline{margin:0;padding-left:18px}.lec-outline li{margin-bottom:8px}.lec-outline a{color:#333;cursor:pointer;font-size:14px}.lec-outline a:hover{color:var(--pku-red)}.lecture-nav .ant-btn{white-space:normal;height:auto;padding:8px 12px}@media (width<=991px){.lecture-side{position:static}}