@import"https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&display=swap";.crash-course{--teel: #19748A;--rich: #033744;--jeans: #98D4EF;--yellow: #EEFF64;--topaz: #00C5A6;--flame: #E55938;--light: #F0F7FA;--mid: #E4EFF4;font-family:Inter,system-ui,sans-serif;background:#fff;color:var(--rich);overflow:hidden;height:100vh}.crash-course *{margin:0;padding:0;box-sizing:border-box}.crash-course .app{display:flex;height:100vh}.crash-course .sidebar{width:260px;min-width:260px;background:var(--rich);display:flex;flex-direction:column;overflow-y:auto}.crash-course .sidebar::-webkit-scrollbar{width:4px}.crash-course .sidebar::-webkit-scrollbar-thumb{background:#ffffff26;border-radius:2px}.crash-course .sidebar-logo{padding:24px 20px 16px;border-bottom:1px solid rgba(25,116,138,.2)}.crash-course .sidebar-logo h1{font-size:22px;font-weight:900;color:#fff;letter-spacing:-.5px}.crash-course .sidebar-logo span{font-size:10px;color:var(--jeans);margin-top:4px;display:block;text-transform:uppercase;letter-spacing:1.5px}.crash-course .progress-wrap{padding:12px 20px 8px}.crash-course .progress-meta{display:flex;justify-content:space-between;font-size:10px;color:var(--jeans);margin-bottom:4px}.crash-course .progress-bar{height:3px;background:#19748a45;border-radius:2px}.crash-course .progress-fill{height:3px;background:var(--topaz);border-radius:2px;transition:width .3s}.crash-course .ch-list{flex:1;overflow-y:auto;padding:4px 0}.crash-course .ch-btn{display:flex;align-items:center;gap:10px;width:100%;padding:8px 20px;background:transparent;border:none;border-left:3px solid transparent;cursor:pointer;text-align:left;transition:all .15s}.crash-course .ch-btn:hover{background:#19748a26}.crash-course .ch-btn.active{background:#19748a33;border-left-color:var(--topaz)}.crash-course .ch-btn .ch-icon{font-size:10px;font-weight:700;color:var(--jeans);min-width:22px}.crash-course .ch-btn.active .ch-icon{color:var(--topaz)}.crash-course .ch-btn .ch-label{font-size:12px;font-weight:500;color:var(--jeans);line-height:1.3}.crash-course .ch-btn.active .ch-label{font-weight:700;color:#fff}.crash-course .main{flex:1;display:flex;flex-direction:column;overflow:hidden}.crash-course .header{background:#fff;border-bottom:1px solid var(--mid);padding:16px 32px;display:flex;justify-content:space-between;align-items:center}.crash-course .header-chap{font-size:10px;font-weight:700;color:var(--teel);text-transform:uppercase;letter-spacing:1.5px}.crash-course .header-title{font-size:20px;font-weight:900;color:var(--rich);line-height:1.2;margin-top:2px}.crash-course .header-sub{font-size:13px;color:var(--teel);margin-top:2px}.crash-course .header-count{font-size:11px;color:#999}.crash-course .content{flex:1;overflow-y:auto;padding:24px 32px 80px}.crash-course .content-inner{max-width:640px}.crash-course .content::-webkit-scrollbar{width:6px}.crash-course .content::-webkit-scrollbar-thumb{background:#ddd;border-radius:3px}.crash-course .nav{border-top:1px solid var(--mid);padding:12px 32px;display:flex;justify-content:space-between;align-items:center;background:#fff}.crash-course .nav-btn{padding:8px 20px;border-radius:6px;font-size:13px;font-weight:600;cursor:pointer;transition:all .15s}.crash-course .nav-prev{border:1px solid var(--mid);background:#fff;color:var(--rich)}.crash-course .nav-prev:hover{background:var(--light)}.crash-course .nav-prev:disabled{background:var(--light);color:#aaa;cursor:default}.crash-course .nav-next{border:none;background:var(--teel);color:#fff}.crash-course .nav-next:hover{opacity:.9}.crash-course .nav-next:disabled{background:var(--mid);color:#aaa;cursor:default}.crash-course .hero-block{background:var(--rich);border-radius:12px;padding:32px 24px;margin-bottom:24px;text-align:center}.crash-course .hero-tag{font-size:11px;font-weight:700;color:var(--topaz);text-transform:uppercase;letter-spacing:2px;margin-bottom:12px}.crash-course .hero-title{font-size:26px;font-weight:900;color:#fff;line-height:1.2;margin-bottom:8px}.crash-course .hero-sub{font-size:14px;color:var(--jeans);margin-top:12px}.crash-course p.body{font-size:14px;line-height:1.7;color:var(--rich);margin:10px 0}.crash-course h3.sec{font-size:18px;font-weight:800;color:var(--rich);margin:28px 0 12px;line-height:1.3}.crash-course .callout{border-left:4px solid var(--teel);padding:14px 16px;border-radius:0 6px 6px 0;margin:16px 0}.crash-course .callout-label{font-size:10px;font-weight:800;text-transform:uppercase;letter-spacing:1.2px;margin-bottom:4px}.crash-course .callout-text{font-size:14px;line-height:1.5;color:var(--rich)}.crash-course .callout-teel{background:#19748a12;border-left-color:var(--teel)}.crash-course .callout-teel .callout-label{color:var(--teel)}.crash-course .callout-dark{background:#03374412;border-left-color:var(--rich)}.crash-course .callout-dark .callout-label{color:var(--rich)}.crash-course .callout-flame{background:#e5593812;border-left-color:var(--flame)}.crash-course .callout-flame .callout-label{color:var(--flame)}.crash-course .callout-topaz{background:#00c5a612;border-left-color:var(--topaz)}.crash-course .callout-topaz .callout-label{color:var(--topaz)}.crash-course table{width:100%;border-collapse:collapse;font-size:13px;margin:16px 0}.crash-course table th{background:var(--rich);color:#fff;padding:10px 12px;text-align:left;font-weight:700;font-size:12px}.crash-course table td{padding:9px 12px;border-bottom:1px solid var(--mid);color:var(--rich)}.crash-course table td:first-child{font-weight:600}.crash-course table tr:nth-child(2n){background:var(--light)}.crash-course .flow{display:flex;flex-direction:column;gap:2px;margin:20px 0}.crash-course .flow-step{padding:10px 16px;border-radius:6px;font-size:13px;border-left:3px solid var(--teel)}.crash-course .flow-step.first,.crash-course .flow-step.last{background:var(--teel);color:#fff;font-weight:700}.crash-course .flow-step.mid{background:var(--light);color:var(--rich)}.crash-course .flow-arrow{text-align:center;font-size:14px;line-height:18px}.crash-course .flow-flame .flow-step{border-left-color:var(--flame)}.crash-course .flow-flame .flow-step.first,.crash-course .flow-flame .flow-step.last{background:var(--flame)}.crash-course .flow-flame .flow-arrow{color:var(--flame)}.crash-course .num-list-item{display:flex;gap:10px;align-items:flex-start;margin-bottom:8px}.crash-course .num-circle{background:var(--teel);color:#fff;border-radius:4px;min-width:24px;height:24px;display:flex;align-items:center;justify-content:center;font-size:12px;font-weight:700}.crash-course .num-circle-lg{border-radius:50%;min-width:32px;height:32px;font-size:14px;font-weight:800}.crash-course .num-text{font-size:14px;color:var(--rich);line-height:1.5;padding-top:2px}.crash-course .num-text-sm{font-size:13px;padding-top:3px}.crash-course .three-cards{display:flex;gap:8px;flex-wrap:wrap;margin:16px 0}.crash-course .three-card{flex:1;min-width:160px;background:var(--rich);border-radius:8px;padding:16px}.crash-course .three-card-label{font-size:13px;font-weight:800;margin-bottom:6px}.crash-course .three-card-desc{color:#fff;font-size:12px;line-height:1.5}.crash-course .info-box{background:var(--light);border-radius:8px;padding:16px;margin:16px 0}.crash-course .info-box-title{font-size:13px;font-weight:700;color:var(--teel);margin-bottom:6px}.crash-course .info-box-text{font-size:13px;color:var(--rich);line-height:1.5}.crash-course .scenario-box{background:var(--rich);border-radius:10px;padding:20px;margin:16px 0}.crash-course .scenario-tag{color:var(--yellow);font-size:11px;font-weight:800;text-transform:uppercase;letter-spacing:1.5px;margin-bottom:8px}.crash-course .scenario-text{color:#fff;font-size:14px;line-height:1.6}.crash-course .def-block{background:var(--rich);border-radius:10px;padding:20px;margin:16px 0;text-align:center}.crash-course .def-tag{font-size:11px;font-weight:700;color:var(--topaz);text-transform:uppercase;letter-spacing:1.5px;margin-bottom:8px}.crash-course .def-text{font-size:15px;color:#fff;line-height:1.6;max-width:520px;margin:0 auto}.crash-course .stack-layer{padding:12px 16px;border-radius:6px;text-align:center;margin-bottom:0}.crash-course .stack-layer-label{font-weight:800;font-size:14px}.crash-course .stack-layer-sub{font-size:11px;opacity:.85;margin-top:2px}.crash-course .stack-arrow{text-align:center;color:var(--teel);font-size:16px;line-height:22px}.crash-course .defense-row{display:flex;gap:12px;margin-bottom:12px;align-items:flex-start}.crash-course .defense-badge{border-radius:6px;padding:4px 10px;font-size:11px;font-weight:800;min-width:72px;text-align:center}.crash-course .defense-text{font-size:13px;color:var(--rich);line-height:1.5;padding-top:2px}.crash-course .check-item{display:flex;gap:8px;align-items:flex-start;margin-bottom:8px}.crash-course .check-icon{font-weight:700;font-size:14px;flex-shrink:0}.crash-course .check-text{font-size:13px;color:var(--rich);line-height:1.5}.crash-course .dot-item{display:flex;gap:8px;align-items:center;margin-bottom:6px}.crash-course .dot{width:6px;height:6px;border-radius:50%;background:var(--teel);flex-shrink:0}.crash-course .dot-text{font-size:13px;color:var(--rich);line-height:1.4}.crash-course .fail-grid{columns:2;column-gap:16px;margin:12px 0}.crash-course .fail-item{font-size:12px;color:var(--rich);line-height:1.4;margin-bottom:6px;break-inside:avoid;display:flex;gap:6px;align-items:flex-start}.crash-course .fail-x{color:var(--flame);font-weight:700}.crash-course .three-flow-diagram{background:var(--rich);border-radius:10px;padding:20px;margin:16px 0}.crash-course .three-flow-title{font-size:12px;font-weight:700;color:#fff;margin-bottom:16px;text-align:center}.crash-course .flow-lane{display:flex;align-items:center;gap:6px;margin-bottom:14px}.crash-course .flow-lane:last-child{margin-bottom:0}.crash-course .lane-label{writing-mode:vertical-rl;transform:rotate(180deg);font-size:9px;font-weight:800;letter-spacing:1.2px;text-transform:uppercase;min-width:18px;display:flex;align-items:center;justify-content:center;height:36px}.crash-course .lane-boxes{display:flex;align-items:center;gap:4px;flex:1;flex-wrap:nowrap;overflow-x:auto}.crash-course .lane-box{border-radius:4px;padding:5px 8px;font-size:10px;font-weight:600;text-align:center;flex:1;min-width:0;white-space:nowrap}.crash-course .lane-arrow{font-size:14px;flex-shrink:0;line-height:1}.crash-course .route-diagram{background:var(--rich);border-radius:10px;padding:20px;margin:16px 0}.crash-course .route-title{font-size:12px;font-weight:700;color:#fff;margin-bottom:16px;text-align:center}.crash-course .route-section{border-radius:8px;padding:12px;margin-bottom:8px}.crash-course .route-section-label{font-size:10px;font-weight:800;text-transform:uppercase;letter-spacing:1.2px;margin-bottom:8px}.crash-course .route-pills{display:flex;flex-wrap:wrap;gap:4px}.crash-course .route-pill{border-radius:4px;padding:4px 8px;font-size:10px;font-weight:600}.crash-course .route-arrow-wrap{text-align:center;padding:4px 0}.crash-course .route-arrow-line{width:2px;height:12px;margin:0 auto}.crash-course .route-arrow-tri{font-size:10px;font-weight:700}.crash-course .route-decision{border-radius:8px;padding:12px 16px;margin:4px 0 8px;text-align:center}.crash-course .route-decision-label{font-size:10px;font-weight:800;text-transform:uppercase;letter-spacing:1.2px;margin-bottom:2px}.crash-course .route-decision-text{font-size:13px;font-weight:700}.crash-course .cta-block{background:var(--teel);border-radius:10px;padding:24px 20px;margin-top:24px;text-align:center}.crash-course .cta-line1{font-size:22px;font-weight:900;color:#fff;line-height:1.3}.crash-course .cta-line2{font-size:22px;font-weight:900;color:var(--yellow);line-height:1.3}.crash-course .cta-url{margin-top:12px;font-size:12px;color:var(--jeans)}.crash-course .lang-switch{display:flex;gap:0;padding:8px 20px 4px}.crash-course .lang-btn{flex:1;padding:5px 0;border:1px solid rgba(25,116,138,.3);background:transparent;color:var(--jeans);font-size:11px;font-weight:600;cursor:pointer;transition:all .15s}.crash-course .lang-btn:first-child{border-radius:4px 0 0 4px}.crash-course .lang-btn:last-child{border-radius:0 4px 4px 0}.crash-course .lang-btn.active{background:var(--teel);border-color:var(--teel);color:#fff}.crash-course .lang-btn:not(.active):hover{background:#19748a26}.crash-course .mobile-menu{position:fixed;top:12px;left:12px;z-index:1000;background:var(--rich);color:#fff;border:none;border-radius:6px;width:36px;height:36px;cursor:pointer;font-size:18px;display:none;align-items:center;justify-content:center}@media(max-width:700px){.crash-course .sidebar{position:fixed;top:0;left:0;bottom:0;z-index:999;transform:translate(-100%);transition:transform .3s}.crash-course .sidebar.open{transform:translate(0)}.crash-course .mobile-menu{display:flex}.crash-course .header{padding:16px 16px 16px 56px}.crash-course .content{padding:24px 16px 80px}.crash-course .nav{padding:12px 16px}.crash-course .fail-grid{columns:1}.crash-course .three-cards{flex-direction:column}.crash-course .lane-boxes{overflow-x:auto}}