:root{--base-color: #2F4F4F;--text-color: #FFFFFF;--accent-color: #008080;--border-color: #4a6868;--bg-hover-color: #3a5f5f;--bg-component-color: #253e3e}body{margin:0;font-family:Inter,Noto Sans JP,sans-serif;background-color:var(--base-color);color:var(--text-color)}.app-container{display:flex;height:100vh;overflow:hidden}.sidebar{width:280px;flex-shrink:0;background-color:var(--bg-component-color);padding:20px;border-right:1px solid var(--border-color);overflow-y:auto}.sidebar h1{font-size:1.5rem;color:var(--accent-color);margin-top:0;padding-bottom:10px;border-bottom:1px solid var(--border-color)}.sidebar ul{list-style:none;padding:0}.sidebar li a{display:block;color:var(--text-color);text-decoration:none;padding:12px 15px;border-radius:6px;margin-bottom:8px;transition:background-color .2s ease}.sidebar li a:hover{background-color:var(--bg-hover-color)}.sidebar li a.active{background-color:var(--accent-color);font-weight:700}.study-page{flex-grow:1;display:flex;flex-direction:column;height:100vh}.study-header{padding:10px 20px;display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid var(--border-color);background-color:var(--bg-component-color);flex-shrink:0}.study-header h2{margin:0;font-size:1.2rem;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.header-controls{display:flex;align-items:center;gap:10px}.language-selector select{background-color:var(--base-color);color:var(--text-color);border:1px solid var(--border-color);padding:8px 12px;border-radius:6px;font-size:.9rem}.jump-mode-switch{display:flex;align-items:center;gap:8px;cursor:pointer}.jump-mode-switch input{cursor:pointer}.data-buttons{display:flex;gap:10px}.btn{background-color:var(--bg-hover-color);border:1px solid var(--border-color);color:var(--text-color);padding:8px 12px;border-radius:6px;cursor:pointer;font-size:.9rem;transition:background-color .2s}.btn:hover{background-color:var(--accent-color)}.btn.active{background-color:var(--accent-color);font-weight:700}.main-content{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:1px;background-color:var(--border-color);flex-grow:1;overflow:hidden}.column{background-color:var(--base-color);overflow-y:auto;padding:20px}.column::-webkit-scrollbar{width:8px}.column::-webkit-scrollbar-track{background:var(--bg-component-color)}.column::-webkit-scrollbar-thumb{background-color:var(--accent-color);border-radius:4px}.player-container{position:sticky;top:20px}.player-container iframe{width:100%;aspect-ratio:16 / 9;border:none;border-radius:8px}.content-row{display:flex;align-items:stretch;gap:1px;background-color:var(--border-color);margin-bottom:12px;border-radius:6px;overflow:hidden;transition:box-shadow .3s,background-color .3s}.content-row.bookmarked{box-shadow:0 0 0 2px var(--accent-color)}.content-row.active{background-color:var(--bg-hover-color)}.subtitle-cell,.note-cell{background-color:var(--bg-component-color);padding:12px;flex:1}.subtitle-time{font-size:.8rem;color:var(--accent-color);margin-bottom:4px}.note-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:4px}.note-timestamp{font-size:.8rem;color:var(--accent-color)}.note-timestamp.jumpable,.subtitle-time.jumpable{cursor:pointer;text-decoration:underline}.note-timestamp.jumpable:hover,.subtitle-time.jumpable:hover{color:#00a0a0}.timestamp-edit-btn{background:none;border:1px solid var(--accent-color);color:var(--accent-color);padding:2px 6px;font-size:.7rem;border-radius:4px;cursor:pointer;transition:background-color .2s,color .2s}.timestamp-edit-btn:hover{background-color:var(--accent-color);color:var(--text-color)}.timestamp-edit-btn.recording{background-color:#c00;border-color:#c00;color:var(--text-color)}.note-editor textarea{width:100%;min-height:60px;background-color:var(--bg-component-color);color:var(--text-color);border:1px solid var(--border-color);border-radius:4px;padding:10px;font-family:inherit;font-size:.9rem;resize:vertical;box-sizing:border-box;transition:border-color .2s ease}.note-editor textarea:focus{outline:none;border-color:var(--accent-color)}.note-display{min-height:82px;width:100%;box-sizing:border-box}.note-display>*:first-child{margin-top:0}.note-display>*:last-child{margin-bottom:0}.note-display h1,.note-display h2,.note-display h3{color:var(--accent-color);border-bottom:1px solid var(--border-color);padding-bottom:4px;margin-top:1em}.note-display ul,.note-display ol{padding-left:20px}.note-display code{background-color:var(--base-color);padding:2px 5px;border-radius:4px;font-family:monospace}.note-display pre{background-color:var(--base-color);padding:10px;border-radius:4px;white-space:pre-wrap}.note-display blockquote{border-left:3px solid var(--accent-color);padding-left:10px;margin-left:0;color:#ccc}.landing-page{width:100%;max-width:960px;margin:0 auto;padding:40px 20px;text-align:center}.landing-header{margin-bottom:60px}.landing-header h1{font-size:3rem;color:var(--accent-color)}.landing-header p{font-size:1.2rem;color:#ccc}.course-list h2{font-size:2rem;border-bottom:2px solid var(--border-color);padding-bottom:10px;margin-bottom:40px}.course-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:20px}.course-card{background-color:var(--bg-component-color);padding:20px;border-radius:8px;text-decoration:none;color:var(--text-color);border:1px solid var(--border-color);transition:transform .2s ease,box-shadow .2s ease;text-align:left}.course-card:hover{transform:translateY(-5px);box-shadow:0 10px 20px #0003}.course-card h3{margin:0 0 10px;color:var(--accent-color)}.course-card p{margin:0;color:#ccc}.theme-switcher{display:flex;align-items:center;gap:8px;margin-top:20px;justify-content:center}.theme-switcher input[type=color]{-webkit-appearance:none;-moz-appearance:none;appearance:none;width:28px;height:28px;background-color:transparent;border:none;cursor:pointer}.theme-switcher input[type=color]::-webkit-color-swatch{border-radius:50%;border:2px solid var(--border-color)}.theme-switcher input[type=color]::-moz-color-swatch{border-radius:50%;border:2px solid var(--border-color)}.header-controls .theme-switcher{margin-top:0}.bookmark-icon{color:var(--accent-color)}.bookmark-dropdown{position:relative}.bookmark-dropdown .bookmark-list{display:none;position:absolute;top:100%;right:0;background-color:var(--bg-component-color);border:1px solid var(--border-color);border-radius:6px;min-width:250px;z-index:10;box-shadow:0 5px 15px #0003;max-height:300px;overflow-y:auto}.bookmark-dropdown:hover .bookmark-list{display:block}.bookmark-list>div{padding:10px 15px;cursor:pointer;border-bottom:1px solid var(--border-color)}.bookmark-list>div:last-child{border-bottom:none}.bookmark-list>div:hover{background-color:var(--bg-hover-color)}.bookmark-list>div strong{display:block;color:var(--accent-color)}.bookmark-list>div span{font-size:.9em;color:#ccc;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;display:block}.modal-overlay{position:fixed;inset:0;background-color:#000000b3;display:flex;justify-content:center;align-items:center;z-index:1000}.modal-content{background-color:var(--bg-component-color);padding:30px;border-radius:8px;border:1px solid var(--border-color);width:100%;max-width:500px}.modal-content h2{margin-top:0;color:var(--accent-color)}.shortcut-list{display:flex;flex-direction:column;gap:15px;margin:20px 0}.shortcut-item{display:flex;justify-content:space-between;align-items:center}.shortcut-key{background-color:var(--base-color);border:1px solid var(--border-color);color:var(--text-color);padding:8px 12px;border-radius:6px;cursor:pointer;min-width:150px;text-align:center}.shortcut-key:hover{border-color:var(--accent-color)}.modal-actions{display:flex;justify-content:flex-end;gap:10px;margin-top:20px}.dark-mode-toggle{background:none;border:1px solid var(--border-color);border-radius:50%;width:32px;height:32px;cursor:pointer;font-size:1.1rem;display:flex;align-items:center;justify-content:center;transition:background-color .2s,transform .2s}.dark-mode-toggle:hover{background-color:var(--bg-hover-color);transform:scale(1.1)}.subtitle-search{display:flex;align-items:center;gap:8px}.search-input-wrapper{position:relative;display:flex;align-items:center}.search-input{background-color:var(--base-color);color:var(--text-color);border:1px solid var(--border-color);padding:8px 30px 8px 12px;border-radius:6px;font-size:.9rem;width:180px;transition:border-color .2s,width .2s}.search-input:focus{outline:none;border-color:var(--accent-color);width:220px}.search-input::placeholder{color:var(--text-secondary-color, #999)}.search-clear-btn{position:absolute;right:8px;background:none;border:none;color:var(--text-secondary-color, #999);cursor:pointer;font-size:.8rem;padding:2px}.search-clear-btn:hover{color:var(--text-color)}.search-results-info{display:flex;align-items:center;gap:4px}.search-count{font-size:.85rem;color:var(--text-secondary-color, #ccc);min-width:50px}.search-nav-btn{background:none;border:1px solid var(--border-color);color:var(--text-color);padding:4px 8px;border-radius:4px;cursor:pointer;font-size:.7rem;transition:background-color .2s}.search-nav-btn:hover:not(:disabled){background-color:var(--bg-hover-color)}.search-nav-btn:disabled{opacity:.4;cursor:not-allowed}.content-row.search-highlight{box-shadow:0 0 0 2px orange}