.courses-page{height:calc(100vh - 60px);height:calc(100dvh - 60px);min-height:0;background:linear-gradient(135deg,#171a27,#24283b);color:#f1f5f9;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}
.course-sidebar{height:100%;overflow-y:auto;padding:24px 30px 32px;box-sizing:border-box;scrollbar-width:thin}
.course-catalog{max-width:1100px;margin:auto}.course-heading{margin-bottom:24px}.course-heading small{color:#b4a5ff;letter-spacing:.12em}.course-heading h1{font-size:26px;margin:8px 0}.course-heading p{font-size:14px;color:#a9b3ca}
.course-loading,.course-empty{display:grid;min-height:180px;place-items:center;color:#b1bacf;text-align:center}.course-category{margin-bottom:18px}.category-header{display:flex;align-items:center;justify-content:space-between;width:100%;padding:12px 15px;border:0;border-radius:9px;background:rgba(255,255,255,.06);color:#fff;text-align:left;cursor:pointer}.category-header:hover{background:rgba(255,255,255,.12)}.category-title{font-size:16px;font-weight:600}.category-icon{transition:transform .2s}.category-header:not(.expanded) .category-icon{transform:rotate(180deg)}.course-list{display:flex;flex-direction:column;gap:10px;padding:10px 0}.category-header:not(.expanded)+.course-list{display:none}
.course-item{display:flex;align-items:center;gap:14px;width:100%;padding:12px;border:1px solid transparent;border-radius:10px;background:rgba(255,255,255,.035);color:#fff;text-align:left;cursor:pointer}.course-item:hover,.course-item.active{background:rgba(102,126,234,.2);border-color:rgba(151,139,255,.25)}.course-thumbnail{display:grid;flex:0 0 84px;width:84px;height:64px;place-items:center;overflow:hidden;border-radius:7px;background:linear-gradient(135deg,#454775,#665187)}.course-thumbnail:empty::after{content:'图文';font-size:14px;color:#dedaf3}.course-thumbnail img{width:100%;height:100%;object-fit:cover}.course-info{min-width:0}.course-title,.course-summary{display:block}.course-title{font-size:15px;font-weight:600;line-height:1.5}.course-summary{margin-top:6px;color:#a9b3ca;font-size:13px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.course-empty--inline{min-height:auto;padding:12px}
.course-reader{max-width:900px;margin:0 auto;border:1px solid #dce2ec;border-radius:16px;background:#fff;color:#243147;overflow:hidden}.course-reader[hidden]{display:none}.is-reading .course-catalog{display:none}.course-reader__bar{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:22px 28px;border-bottom:1px solid #edf0f6}.course-reader__bar strong{font-size:22px;line-height:1.5;overflow-wrap:anywhere}.course-reader__bar button{flex-shrink:0;padding:9px 12px;border:1px solid #dedaf5;border-radius:8px;background:#f3f1fd;color:#5a43ac;font-size:13px;cursor:pointer}.course-reader__summary{margin:20px 28px 0;padding:14px 16px;background:#f5f7fb;border-radius:8px;color:#68768a;font-size:14px;line-height:1.8;white-space:pre-wrap}.course-reader__summary:empty{display:none}
.course-article{padding:22px 28px 36px;font-size:16px;line-height:1.9;overflow-wrap:anywhere}.course-article p{margin:0 0 1em}.course-article h1,.course-article h2,.course-article h3{color:#17233a;line-height:1.5;margin:1.3em 0 .6em}.course-article h1{font-size:26px}.course-article h2{font-size:22px}.course-article h3{font-size:19px}.course-article img{display:block;max-width:100%;height:auto;margin:18px auto;border-radius:8px}.course-article a{color:#6247b8;text-decoration:underline}.course-article blockquote{margin:16px 0;padding:12px 18px;border-left:4px solid #9e8bd9;background:#f6f4fc;color:#5f5975}.course-article ol,.course-article ul{padding-left:1.8em;margin:1em 0}.course-article ol{list-style:decimal}.course-article ul{list-style:disc}.course-article li{margin:.4em 0}
@media(max-width:700px){.course-sidebar{padding:16px}.course-reader__bar{padding:16px;align-items:flex-start}.course-reader__bar strong{font-size:19px}.course-reader__summary{margin:16px 16px 0}.course-article{padding:18px 16px 28px}.course-reader{border-radius:12px}.course-thumbnail{flex-basis:72px;width:72px;height:58px}}