:root{--paper:#fff;--ink:#283b36;--accent:#8d4b3a;--soft:#f7f8f5;--line:#dde3dc;--muted:#65756c;--blue:#8d4b3a;font-family:'文学宋体',serif;color:var(--ink);background:var(--paper)}
body{background:var(--paper);color:var(--ink)}
button,input,select{font-family:inherit}a{color:inherit}button,.button{color:var(--ink)}
a:focus-visible,button:focus-visible,summary:focus-visible{outline:2px solid var(--accent);outline-offset:6px}
.catalog-shell{width:min(1400px,calc(100% - 96px));max-width:none;padding:0;margin:0 auto}
.catalog-top{display:flex;align-items:center;justify-content:space-between;gap:24px;padding:29px 0 22px;border-bottom:1px solid var(--line);font-size:14px;letter-spacing:.08em}
.catalog-top nav{display:flex;gap:27px}.catalog-top a:hover{color:var(--accent)}
.catalog-hero{display:grid;grid-template-columns:1fr auto;align-items:end;gap:25px;padding:38px 0 30px}
.catalog-hero h1{font-family:'小薇','文学宋体',serif;font-size:clamp(38px,4vw,54px);font-weight:400;letter-spacing:.08em;line-height:1.2;margin:0 0 12px}
.catalog-hero p{margin:0;color:var(--muted);font-size:14px;letter-spacing:.18em}
.catalog-total{display:flex;align-items:baseline;gap:12px;padding-bottom:7px;color:var(--muted);font-size:14px;white-space:nowrap}
.catalog-total b{color:var(--accent);font-size:36px;font-weight:400;line-height:1}
.catalog-filters{display:flex;flex-wrap:wrap;gap:10px 28px;border-bottom:1px solid var(--ink);padding:0 0 16px}
.catalog-filters button{border:0;padding:7px 0;background:none;border-radius:0;color:var(--muted);font-size:15px;letter-spacing:.07em;position:relative}
.catalog-filters button:hover{color:var(--accent);background:none}.catalog-filters button[aria-pressed=true]{color:var(--accent)}
.catalog-filters button[aria-pressed=true]::after{content:'';position:absolute;left:0;right:0;bottom:-17px;height:2px;background:var(--accent)}
.course-catalog{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:44px 40px;padding-top:30px}
.course-entry{position:relative;display:block;min-width:0;padding:0;border:0;background:var(--paper)}
.course-number{padding-top:5px;color:var(--accent);font-size:13px;font-variant-numeric:tabular-nums;line-height:1.8}
.course-open{display:block;min-width:0}.course-open:hover h2{color:var(--accent)}
.course-preview{display:block;width:100%;height:auto;aspect-ratio:16/9;object-fit:contain;max-width:100%;margin:0;border:0;border-radius:0;box-shadow:none;background:var(--paper)}
.course-caption{display:grid;grid-template-columns:28px minmax(0,1fr);gap:10px;padding:15px 48px 0 0}
.course-copy{min-width:0}.course-open h2{margin:0;color:var(--ink);font-family:'小薇','文学宋体',serif;font-size:25px;font-weight:400;line-height:1.5;overflow-wrap:anywhere}
.course-genre{display:block;margin-top:5px;color:var(--muted);font-size:12px;letter-spacing:.12em}
.course-edition{display:block;margin-top:9px;color:var(--accent);font-size:11px;letter-spacing:.16em}
.course-practice{position:absolute;right:0;bottom:0;color:var(--muted);font-size:13px;line-height:1.8;letter-spacing:.1em;padding:7px 0 0}
.course-practice:hover{color:var(--accent)}
.catalog-footer{display:flex;justify-content:space-between;gap:20px;padding:21px 0 35px;border-top:1px solid var(--line);color:var(--muted);font-size:12px;letter-spacing:.06em}
@media(max-width:1000px){.catalog-shell{width:calc(100% - 56px)}.course-catalog{gap:36px 28px}.course-open h2{font-size:22px}.course-caption{grid-template-columns:24px minmax(0,1fr);gap:8px}}
@media(max-width:700px){.catalog-shell{width:calc(100% - 36px)}.catalog-top{padding:20px 0 17px;font-size:12px;letter-spacing:0;gap:12px}.catalog-top nav{gap:15px}.catalog-hero{padding:28px 0 25px;gap:12px}.catalog-hero h1{font-size:38px;margin-bottom:10px;letter-spacing:.07em}.catalog-hero p{font-size:12px;letter-spacing:.16em}.catalog-total{gap:5px;font-size:12px}.catalog-total b{font-size:28px}.catalog-filters{gap:8px 23px}.catalog-filters button{font-size:14px}.course-catalog{grid-template-columns:1fr;gap:32px;padding-top:24px}.course-open h2{font-size:24px}.course-caption{padding-top:13px;grid-template-columns:25px minmax(0,1fr);gap:9px}.course-number{padding-top:5px;font-size:12px}.course-genre{font-size:11px}.course-practice{font-size:12px}.catalog-footer{font-size:11px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}}

/* 投影目录横向展示：大屏三列，适合课堂快速选择 */
@media(min-width:1001px){.course-catalog{grid-template-columns:repeat(3,minmax(0,1fr));gap:36px 28px}.course-preview{aspect-ratio:16/9;object-fit:cover}.course-caption{padding-right:8px}.course-open h2{font-size:22px}}
@media(max-width:1000px) and (min-width:701px){.course-catalog{grid-template-columns:repeat(2,minmax(0,1fr))}}


.course-versions{display:flex;gap:8px;margin:14px 48px 0 48px;flex-wrap:wrap}.course-versions a{padding:6px 10px;border:1px solid #d8ceb9;border-radius:999px;color:var(--muted);font-size:12px;text-decoration:none}.course-versions a:hover{color:var(--accent);border-color:var(--accent)}@media(max-width:700px){.course-versions{margin-left:43px;margin-right:0}}


/* 目录卡片：每个课件一张卡，版本入口集中在卡片底部 */
.course-catalog{grid-template-columns:repeat(3,minmax(0,1fr));gap:42px 30px}.course-card{min-width:0}.course-links{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin:16px 0 0 38px}.course-links a{display:inline-flex;align-items:center;min-height:32px;padding:5px 12px;border:1px solid var(--line);border-radius:999px;text-decoration:none;color:var(--muted);font-size:12px;letter-spacing:.04em}.course-links a:hover{border-color:var(--accent);color:var(--accent);background:var(--soft)}.course-links .version-main{border-color:var(--accent);color:var(--accent)}.course-links .version-projection{border-color:#b99157;color:#8b6a36}.course-links .course-practice{position:static;padding:5px 12px;margin:0;font-size:12px;line-height:1.4;letter-spacing:.04em}@media(max-width:1000px){.course-catalog{grid-template-columns:repeat(2,minmax(0,1fr));gap:36px 24px}}@media(max-width:700px){.course-catalog{grid-template-columns:1fr;gap:32px;padding-top:24px}.course-links{margin-left:34px}.course-links a{min-height:30px;padding-inline:10px}}


/* 底部入口改为简洁横向导航 */
.course-links{display:flex;align-items:center;gap:0;margin:16px 0 0 38px;border-top:1px solid var(--line);padding-top:11px}.course-links a,.course-links .course-practice{display:inline-flex;align-items:center;min-height:24px;padding:0 14px;border:0;border-radius:0;background:transparent;color:var(--muted);font-size:13px;letter-spacing:.03em;text-decoration:none;line-height:1}.course-links a:first-child{padding-left:0}.course-links a+a{border-left:1px solid var(--line)}.course-links a:hover{background:transparent;color:var(--accent)}.course-links .version-main{color:var(--accent);border-color:transparent}.course-links .version-projection{color:#8b6a36}.course-links .course-practice{position:static;padding-top:0;margin:0}@media(max-width:700px){.course-links{margin-left:34px}.course-links a,.course-links .course-practice{padding-inline:10px;font-size:12px}}


/* 标题与课程类别同行显示 */
.course-copy{display:flex;align-items:baseline;gap:12px;flex-wrap:wrap}.course-copy h2{flex:0 1 auto}.course-copy .course-genre{display:inline-block;margin-top:0;white-space:nowrap;letter-spacing:.08em}.course-links{margin-top:12px}@media(max-width:700px){.course-copy{gap:8px}.course-copy .course-genre{font-size:11px}}


/* 课程课件作为每张卡片的主入口，突出显示 */
.course-links .version-main{font-size:15px;font-weight:600;color:var(--accent);letter-spacing:.08em;padding-left:0;padding-right:18px}.course-links .version-main:hover{color:var(--ink)}@media(max-width:700px){.course-links .version-main{font-size:14px}}


/* 教师活动：课程卡片只保留一个入口，资源操作在展开面板中按本课归组。 */
.course-teacher-activity{margin:13px 0 0 38px;min-width:0}
.course-activity-toggle{display:inline-flex;align-items:center;min-height:34px;padding:6px 15px;border:1px solid var(--accent);border-radius:2px;background:var(--accent);color:var(--paper);font-family:inherit;font-size:13px;font-weight:600;letter-spacing:.08em;line-height:1.4;cursor:pointer}
.course-activity-toggle:hover,.course-activity-toggle[aria-expanded=true]{background:var(--ink);border-color:var(--ink);color:var(--paper)}
.course-activity-panel{margin-top:9px;padding:10px 0 0;border-top:1px solid var(--line)}
.course-activity-head{display:flex;align-items:baseline;justify-content:space-between;gap:14px;color:var(--ink);font-size:14px;line-height:1.55}
.course-activity-note{color:var(--muted);font-size:12px;letter-spacing:.03em;text-align:right}
.course-activity-primary{display:flex;align-items:center;gap:16px;margin-top:10px}
.course-activity-primary button,.course-resource-actions button,.course-resource-link{padding:4px 0;border:0;border-bottom:1px solid transparent;border-radius:0;background:transparent;color:var(--muted);font-family:inherit;font-size:13px;line-height:1.5;white-space:nowrap;cursor:pointer;text-decoration:none}
.course-activity-primary button:hover,.course-resource-actions button:hover,.course-resource-link:hover{color:var(--accent);border-bottom-color:var(--accent)}
.course-activity-primary .course-activity-replace,.course-activity-primary .course-activity-add{color:var(--accent);font-weight:600}
.course-activity-empty{margin:11px 0 0;color:var(--muted);font-size:13px;line-height:1.6}
.course-resource-list{margin-top:12px}
.course-resource-row{display:block;padding:11px 0;border-top:1px solid var(--line);min-width:0}
.course-resource-copy{display:grid;gap:3px;min-width:0;line-height:1.5}
.course-resource-copy strong{font-size:14px;font-weight:400;overflow-wrap:anywhere}
.course-resource-copy span{color:var(--muted);font-size:12px;line-height:1.5;overflow-wrap:anywhere}
.course-resource-actions{display:flex;align-items:center;justify-content:flex-start;gap:12px;margin-top:8px;flex-wrap:wrap;flex-shrink:0}
.course-resource-actions button.primary{color:var(--accent);font-weight:600}
@media(max-width:700px){.course-teacher-activity{margin-left:34px}.course-activity-head{display:block}.course-activity-note{display:block;margin-top:3px;text-align:left}.course-resource-row{display:block}.course-resource-actions{justify-content:flex-start;margin-top:7px;gap:10px}}
.resource-list-note{margin:14px 0;color:var(--muted);font-size:12px}

/* 教师版本投影：封面、链接和标题始终指向同一份当前资源。 */
.course-preview-frame{display:block;position:relative;width:100%;aspect-ratio:16/9;overflow:hidden;background:var(--paper)}
.course-preview-frame .course-preview{width:100%;height:100%;object-fit:cover}
.course-preview-frame.has-personal-preview{outline:1px solid var(--accent);outline-offset:-1px}
.course-preview-frame>.course-preview-personal{position:absolute;inset:0;z-index:1;width:100%;height:100%;object-fit:contain;background:var(--paper)}
.course-preview-file{display:flex;flex-direction:column;justify-content:flex-end;gap:9px;width:100%;height:100%;padding:clamp(18px,3vw,32px);background:linear-gradient(135deg,#fff 0%,#f7f8f5 66%,#efe5dc 100%);color:var(--ink)}
.course-preview-eyebrow{color:var(--accent);font-size:11px;letter-spacing:.18em}
.course-preview-file strong{max-width:24ch;font-family:'小薇','文学宋体',serif;font-size:clamp(20px,2.4vw,32px);font-weight:400;line-height:1.3;overflow-wrap:anywhere}
.course-preview-file small{color:var(--muted);font-size:11px;letter-spacing:.08em}
.course-personal-mark{display:inline-block;margin-left:8px;color:var(--accent);font-size:11px;font-weight:400;letter-spacing:.08em;white-space:nowrap}
.course-card.has-personal-version .course-open h2{color:var(--accent)}
.course-extra-resources{margin:14px 0 0 38px;border-top:1px solid var(--line)}
.course-extra-heading{display:flex;align-items:baseline;justify-content:space-between;gap:12px;padding:9px 0 5px;color:var(--muted);font-size:11px;letter-spacing:.08em}
.course-extra-row{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:8px 0;border-bottom:1px solid var(--line)}
.course-extra-copy{min-width:0;display:grid;gap:2px}
.course-extra-copy strong{font-size:12px;font-weight:400;overflow-wrap:anywhere}
.course-extra-copy span{color:var(--muted);font-size:10px;overflow-wrap:anywhere}
.course-extra-actions{display:flex;align-items:center;gap:10px;flex-wrap:wrap;flex-shrink:0}
.course-extra-actions a{color:var(--accent);font-size:11px;white-space:nowrap}
.directory-personal-row{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:12px 0;border-bottom:1px solid var(--line)}
.directory-personal-copy{display:grid;gap:3px;min-width:0}
.directory-personal-eyebrow{color:var(--accent);font-size:10px;letter-spacing:.12em}
.directory-personal-copy strong{font-size:15px;font-weight:400;overflow-wrap:anywhere}
.directory-personal-copy small{color:var(--muted);font-size:11px;overflow-wrap:anywhere}
.directory-personal-actions{display:flex;align-items:center;gap:14px;flex-shrink:0}
.directory-personal-actions a{color:var(--accent);font-size:12px;white-space:nowrap}
.course-extra-resources .directory-personal-row{padding:8px 0;gap:12px}
.course-extra-resources .directory-personal-copy strong{font-size:12px}
.course-extra-resources .directory-personal-copy small{font-size:10px}
.course-extra-resources .directory-personal-eyebrow{font-size:9px}
.course-extra-resources .directory-personal-actions{gap:10px}
.course-extra-resources .directory-personal-actions a{font-size:11px}
@media(max-width:700px){.course-extra-resources{margin-left:34px}.course-extra-row,.directory-personal-row{display:block}.course-extra-actions,.directory-personal-actions{justify-content:flex-start;margin-top:7px}}

/* 上传只在教师点击替换/增加时出现，不再占用目录底部空间。 */
.teacher-resource-dialog{width:min(680px,calc(100% - 32px));max-width:none;border:1px solid var(--line);border-radius:4px;padding:22px;background:var(--paper);color:var(--ink);box-shadow:0 18px 60px rgba(40,59,54,.16)}
.teacher-resource-dialog::backdrop{background:rgba(40,59,54,.14)}
.teacher-resource-dialog-head{display:flex;align-items:flex-start;justify-content:space-between;gap:18px;padding-bottom:16px;border-bottom:1px solid var(--line)}
.teacher-resource-dialog-head h2{margin:0;font-family:'小薇','文学宋体',serif;font-size:22px;font-weight:400}
.teacher-resource-dialog-close{border:0;background:transparent;color:var(--muted);font:inherit;font-size:13px;cursor:pointer;padding:2px 0}.teacher-resource-dialog-close:hover{color:var(--accent)}
.teacher-resource-dialog #teacherTools{padding-top:18px}.teacher-resource-dialog .tools{margin:0 0 14px}.teacher-resource-dialog .resource-push-hint{margin:14px 0 0}
.teacher-resource-dialog .status{margin:14px 0 0}.teacher-resource-dialog .muted{font-size:12px}
.course-personal-mark{overflow-wrap:anywhere}
@media(max-width:700px){.teacher-resource-dialog{width:calc(100% - 24px);padding:18px}.teacher-resource-dialog-head h2{font-size:20px}}