:root{color-scheme:light;--ink:#242b38;--muted:#697487;--blue:#507ed5;--line:#e0e5ef;--paper:#f3f5fa;--surface:#fff;font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif;font-synthesis:none}
*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);min-width:280px}button,a{-webkit-tap-highlight-color:transparent}button{font:inherit;cursor:pointer}button:disabled{opacity:.3;cursor:default}a{color:inherit;text-decoration:none}button:focus-visible,a:focus-visible,[tabindex]:focus-visible{outline:3px solid #83a5ee;outline-offset:4px}[hidden]{display:none!important}
.site-header{min-height:82px;padding:20px 36px;display:flex;align-items:center;justify-content:space-between;gap:20px;border-bottom:1px solid var(--line)}.brand{display:flex;align-items:baseline;gap:18px;white-space:nowrap}.brand strong{font-size:25px;letter-spacing:-.7px}.brand>span{font-size:14px;color:var(--muted)}.header-actions,.slide-actions,.page-controls{display:flex;align-items:center;gap:10px}.course-meta{font-size:13px;color:var(--muted);margin-right:12px;white-space:nowrap}
.button{border:1px solid transparent;border-radius:10px;padding:10px 15px;min-height:42px;display:inline-flex;align-items:center;justify-content:center;gap:8px;font-size:14px;line-height:1.4;white-space:nowrap;transition:background .15s,box-shadow .15s}.button svg{width:18px;height:18px;fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round}.secondary{background:#ffffffb8;border-color:var(--line);color:#47536a}.secondary:hover{background:#fff;box-shadow:0 3px 12px #2534510c}.primary{background:var(--blue);color:#fff;box-shadow:0 4px 12px #507ed525}.primary:hover{background:#436fc3}.text-button{background:transparent;color:var(--muted)}
main{padding:26px 30px 8px}.presentation{max-width:1600px;margin:auto}.slide-stage{position:relative;width:min(100%,calc((100svh - 235px)*16/9));aspect-ratio:16/9;margin:0 auto;overflow:hidden;border-radius:13px;background:#fff;box-shadow:0 12px 38px #2534530e,0 0 0 1px #dfe4ee;touch-action:pan-y pinch-zoom}.slide-image{display:block;width:100%;height:100%;object-fit:contain;user-select:none}.stage-arrow{position:absolute;top:calc(50% - 24px);width:40px;height:48px;border:1px solid #fff9;border-radius:10px;background:#fffD;color:#36445f;font-size:30px;line-height:1;box-shadow:0 3px 18px #1112;opacity:0;transition:opacity .15s}.stage-arrow.left{left:14px}.stage-arrow.right{right:14px}.slide-stage:hover .stage-arrow,.stage-arrow:focus-visible{opacity:.95}.stage-arrow:disabled{visibility:hidden}.slide-stage:fullscreen{width:100%;height:100%;aspect-ratio:auto;border-radius:0;background:#101217;box-shadow:none;display:flex;align-items:center;justify-content:center}.slide-stage:fullscreen .slide-image{object-fit:contain}.slide-stage:fullscreen .stage-arrow{opacity:.6}
.slide-toolbar{max-width:1400px;margin:20px auto 0;display:flex;justify-content:space-between;align-items:center;gap:20px}.slide-description{display:flex;align-items:center;gap:12px;min-width:0}.section-label{font-size:12px;color:var(--blue);white-space:nowrap;font-weight:600;letter-spacing:.2px}h1{font-size:15px;font-weight:500;margin:0;line-height:1.5;color:#515e75;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.status{text-align:center;padding:25vh 20px;color:var(--muted);font-size:16px}.status a{color:var(--blue);text-decoration:underline}
.navigation{position:relative;max-width:1600px;padding:12px 30px 22px;margin:0 auto;min-height:80px;display:flex;align-items:center;justify-content:center;gap:30px}.keyboard-hint{position:absolute;left:30px;margin:0;font-size:12px;color:#8791a2}.hint-divider{margin:0 6px}.page-button{background:#fff;border-color:var(--line);width:44px;height:40px;padding:6px;font-size:20px}.page-button:not(:disabled):hover{background:#e9eef8}.page-controls{gap:16px}.page-counter{min-width:80px;font-size:16px;text-align:center;font-variant-numeric:tabular-nums;font-weight:600}.page-counter span{color:#8b95a5;font-size:13px;font-weight:400}.mobile-hint{display:none;font-size:11px;color:#8b95a5}.progress-track{position:absolute;left:30px;right:30px;bottom:8px;height:3px;border-radius:3px;background:#e3e8f1;overflow:hidden}.progress-fill{width:3.03%;height:100%;background:#7398df;border-radius:3px;transition:width .2s}
.reading{max-width:1100px;margin:22px auto 12px;padding:25px 30px 30px;border:1px solid var(--line);border-radius:15px;background:#fff}.reading-heading{display:flex;justify-content:space-between;align-items:center;gap:12px}.reading h2{font-size:19px;line-height:1.5;margin:0}.reading-tool{color:var(--muted);font-size:14px;margin:12px 0}.reading-content{white-space:pre-wrap;overflow-wrap:anywhere;font-size:18px;line-height:1.85;margin-top:18px;color:#344057;user-select:text}.cautions{border-top:1px solid var(--line);margin-top:22px;padding-top:12px}.cautions h3{font-size:16px;color:#a36829;margin:8px 0}.cautions ul{margin:10px 0 0;padding-left:22px}.cautions li{font-size:16px;line-height:1.8;color:#566279;margin:7px 0}
.contents-dialog{width:min(1100px,calc(100% - 40px));max-height:88svh;padding:0;border:1px solid var(--line);border-radius:20px;background:var(--paper);box-shadow:0 25px 100px #10182740}.contents-dialog::backdrop{background:#18233e66;backdrop-filter:blur(4px)}.contents-header{position:sticky;top:0;z-index:1;display:flex;align-items:center;justify-content:space-between;padding:24px 28px;background:#f3f5faf5;border-bottom:1px solid var(--line)}.contents-header h2{margin:4px 0 0;font-size:24px}.contents-list{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px;padding:24px 28px 30px}.contents-item{appearance:none;text-align:left;padding:0 0 10px;border:2px solid transparent;background:transparent;border-radius:12px;overflow:hidden;min-width:0}.contents-item:hover{background:#e6ecf7}.contents-item[aria-current="page"]{border-color:#6f95df;background:#e8eef9}.contents-item img{display:block;width:100%;aspect-ratio:16/9;object-fit:contain;background:#e6eaf2;border-radius:8px}.contents-item strong{display:block;padding:10px 9px 0;font-size:13px;line-height:1.6;font-weight:500;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.contents-item span{color:#7082a4;font-variant-numeric:tabular-nums;margin-right:8px}.toast{position:fixed;z-index:20;bottom:32px;left:50%;transform:translateX(-50%);max-width:calc(100% - 32px);padding:12px 22px;border-radius:12px;background:#27334ced;color:#fff;box-shadow:0 6px 22px #17274524;font-size:14px;text-align:center}
.contents-dialog{overflow:hidden}.contents-header{position:relative}.contents-list{overflow-y:auto;max-height:calc(88svh - 110px);scroll-padding:12px}
@media(max-width:900px){.site-header{padding:17px 22px}.brand{gap:12px}.course-meta{display:none}.slide-description{display:block}.section-label{display:block;margin-bottom:3px}.slide-toolbar{gap:12px}.contents-list{gap:15px}.keyboard-hint{display:none}}
@media(max-width:600px){.site-header{padding:15px 16px;min-height:72px;gap:10px}.brand{display:block}.brand strong{font-size:22px}.brand>span{display:block;font-size:11px;margin-top:3px}.header-actions{gap:7px}.header-actions .button{padding:9px 11px;font-size:12px;min-height:39px}.button svg{width:16px;height:16px}.button{padding:9px 12px;min-height:41px;font-size:13px}main{padding:22px 12px 0}.slide-stage{width:100%;border-radius:8px}.slide-toolbar{margin-top:16px;align-items:flex-start;flex-wrap:wrap}.slide-description{width:100%}h1{font-size:14px;white-space:normal}.slide-actions{gap:8px;flex-wrap:wrap}.navigation{padding:14px 16px 26px;min-height:84px;justify-content:space-between;gap:10px}.page-controls{gap:10px}.page-counter{min-width:66px;font-size:15px}.page-button{width:39px;min-height:39px}.mobile-hint{display:block}.progress-track{left:16px;right:16px}.reading{padding:19px 19px 22px;margin-top:20px;border-radius:12px}.reading-content{font-size:17px;line-height:1.85}.reading h2{font-size:18px}.reading-tool{font-size:13px}.cautions li{font-size:15px}.contents-dialog{width:calc(100% - 20px);max-height:90svh;border-radius:15px}.contents-header{padding:19px 18px}.contents-list{grid-template-columns:repeat(2,minmax(0,1fr));padding:18px 14px;gap:14px}.contents-item strong{font-size:12px}.stage-arrow{width:30px;height:38px;top:calc(50% - 19px);font-size:23px}.stage-arrow.left{left:6px}.stage-arrow.right{right:6px}}
@media(pointer:coarse){.stage-arrow{opacity:.5}}@media(max-height:550px) and (orientation:landscape){.site-header{min-height:50px;padding:8px 20px}.brand{display:flex}.brand strong{font-size:20px}.brand>span{font-size:12px}.header-actions .button{min-height:34px;padding:6px 10px}main{padding:12px 20px 0}.slide-stage{width:min(100%,calc((100svh - 140px)*16/9))}.slide-toolbar{margin-top:10px;max-width:100%;align-items:center;flex-wrap:nowrap}.slide-description{width:auto;display:flex}.slide-description .section-label{display:none}h1{font-size:12px}.slide-actions .button{min-height:32px;padding:6px 10px;font-size:12px}.navigation{padding-top:6px;min-height:55px}.page-button{height:32px;min-height:32px;width:34px}.mobile-hint{display:none}}@media(prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto!important}}