:root{--bg-color:#faf9de;--header-bg:#ffffff;--text-color:#333333;--primary-color:#5d4037;--accent-color:#8d6e63;--hover-color:#efebe9;--footer-bg:#4e342e;--footer-text:#d7ccc8;--nav-height:60px;--sidebar-width:250px;--highlight-color:#d7ccc8}*{box-sizing:border-box;margin:0;padding:0}html{scroll-behavior:smooth}body{font-family:'Segoe UI',Roboto,Helvetica,Arial,sans-serif;background-color:var(--bg-color);color:var(--text-color);line-height:1.8;padding-top:var(--nav-height);display:flex;flex-direction:column;min-height:100vh}a{text-decoration:none;color:inherit;transition:0.3s}ul{list-style:none}h1,h2,h3{scroll-margin-top:calc(var(--nav-height) + 20px)}header{position:fixed;top:0;left:0;width:100%;height:var(--nav-height);background:var(--header-bg);box-shadow:0 2px 10px rgba(0,0,0,0.05);z-index:1000;display:flex;align-items:center;justify-content:space-between;padding:0 20px}.header-left-group{display:flex;align-items:center;gap:20px;z-index:1100}.logo{font-size:1.3rem;font-weight:bold;color:var(--primary-color);display:flex;align-items:center;gap:8px}.sound-wrapper{display:flex;align-items:center;background-color:#f5f5f5;border-radius:20px;padding:2px 5px;border:1px solid #e0e0e0}.sound-btn{cursor:pointer;font-size:1.1rem;padding:4px 8px;border-radius:50%;transition:background-color 0.2s;display:flex;align-items:center;justify-content:center;user-select:none}.sound-btn:hover{background-color:#e0e0e0}.sound-selector{position:relative;display:flex;align-items:center;border-left:1px solid #ccc;margin-left:5px;padding-left:5px}.sound-arrow{cursor:pointer;font-size:0.7rem;color:#666;padding:4px 6px;border-radius:4px;transition:0.2s;user-select:none}.sound-arrow:hover{background-color:#e0e0e0;color:var(--primary-color)}.sound-dropdown{position:absolute;top:calc(100% + 10px);left:50%;transform:translateX(-50%);background:#fff;min-width:120px;box-shadow:0 4px 12px rgba(0,0,0,0.15);border-radius:6px;display:none;border:1px solid #eee;z-index:1200;padding:5px 0}.sound-dropdown::before{content:'';position:absolute;top:-6px;left:50%;margin-left:-6px;border-width:6px;border-style:solid;border-color:transparent transparent #fff transparent}.sound-dropdown.show{display:block;animation:fadeIn 0.2s ease}.sound-dropdown li{padding:8px 15px;font-size:0.85rem;color:#555;cursor:pointer;white-space:nowrap;transition:0.2s;display:flex;align-items:center;justify-content:space-between}.sound-dropdown li:hover{background-color:var(--hover-color);color:var(--primary-color)}.sound-dropdown li.active{font-weight:bold;color:var(--primary-color);background-color:#fafafa}.sound-dropdown li.active::after{content:'✓';font-size:0.8rem;margin-left:8px}.nav-container{display:flex;align-items:center}.nav-menu{display:flex;gap:5px}.nav-item{position:relative;padding:0 10px}.nav-link{display:block;line-height:var(--nav-height);color:#555;font-size:1rem;cursor:pointer;padding:0 10px}.nav-link:hover,.nav-item:hover>.nav-link{color:var(--primary-color);background-color:var(--hover-color)}.nav-item.open>.nav-link{color:var(--primary-color);background-color:var(--hover-color)}.dropdown{position:absolute;top:100%;left:0;background:#fff;min-width:180px;box-shadow:0 4px 12px rgba(0,0,0,0.1);border-radius:0 0 4px 4px;opacity:0;visibility:hidden;transform:translateY(10px);transition:all 0.3s ease;z-index:1100;max-height:calc(100vh - var(--nav-height) - 20px);overflow-y:auto}.dropdown::-webkit-scrollbar{width:6px}.dropdown::-webkit-scrollbar-track{background:#f1f1f1}.dropdown::-webkit-scrollbar-thumb{background:#ccc;border-radius:3px}.nav-item.open .dropdown{opacity:1;visibility:visible;transform:translateY(0)}.dropdown li{position:relative}.dropdown li a{display:block;padding:12px 15px;font-size:0.9rem;color:#666;border-bottom:1px solid #f5f5f5;white-space:nowrap}.dropdown li a:hover,.dropdown li:hover>a{background-color:var(--hover-color);color:var(--primary-color)}.submenu{display:none;background-color:#fafafa;list-style:none;padding-left:0;border-left:3px solid var(--accent-color)}.dropdown li.has-submenu.submenu-open>.submenu{display:block;animation:fadeIn 0.3s ease}.dropdown li.has-submenu.submenu-open>.submenu-trigger{background-color:var(--hover-color);color:var(--primary-color)}@keyframes fadeIn{from{opacity:0;transform:translateX(5px)}to{opacity:1;transform:translateX(0)}}.submenu li a{padding-left:30px;font-size:0.85rem;color:#777;border-bottom:none}.submenu li a:hover{background-color:#eee}.hamburger{display:none;cursor:pointer;flex-direction:column;gap:5px;padding:5px;z-index:1100}.hamburger span{display:block;width:25px;height:3px;background-color:var(--primary-color);border-radius:2px;transition:0.3s}.bookmark-toast{position:fixed;top:80px;right:20px;background-color:#fff;border-left:5px solid #ffca28;box-shadow:0 4px 15px rgba(0,0,0,0.15);padding:15px 20px;border-radius:4px;z-index:2000;display:none;animation:slideIn 0.5s ease-out;max-width:300px}@keyframes slideIn{from{opacity:0;transform:translateX(50px)}to{opacity:1;transform:translateX(0)}}.toast-content{display:flex;align-items:flex-start;gap:15px}.toast-icon{font-size:1.5rem}.toast-text p{font-size:0.9rem;color:#555;margin-bottom:5px;line-height:1.4;text-align:left}.key-shortcut{background:#eee;padding:2px 6px;border-radius:3px;font-family:monospace;border:1px solid #ccc;font-size:0.85rem}#bookmark-ok-btn{background-color:var(--primary-color);color:#fff;border:none;padding:5px 12px;border-radius:3px;cursor:pointer;font-size:0.85rem;margin-top:5px;align-self:flex-end;transition:0.2s}#bookmark-ok-btn:hover{background-color:var(--accent-color)}.container{display:flex;max-width:1200px;margin:0 auto;flex:1;width:100%}aside{width:var(--sidebar-width);background-color:rgba(255,255,255,0.4);border-right:1px solid rgba(0,0,0,0.03);padding:20px;position:fixed;top:var(--nav-height);bottom:0;overflow-y:auto;scrollbar-width:thin}aside h3.toc-title{font-size:1rem;color:var(--primary-color);margin-bottom:15px;border-bottom:2px solid var(--accent-color);padding-bottom:5px}#toc-list li{margin-bottom:8px}#toc-list .toc-h2{font-size:0.9rem;font-weight:600;display:block;padding:4px 0}#toc-list .toc-h3{font-size:0.85rem;padding-left:15px;color:#666;border-left:2px solid transparent;display:block;padding:2px 0 2px 15px}#toc-list a:hover{color:var(--primary-color)}#toc-list .toc-h3:hover{border-left-color:var(--accent-color)}main{flex:1;margin-left:var(--sidebar-width);padding:40px;max-width:900px}main h1{font-size:2rem;margin-bottom:20px;color:var(--primary-color)}main h2{font-size:1.5rem;margin-top:30px;margin-bottom:15px;border-left:5px solid var(--accent-color);padding-left:10px}main h3{font-size:1.2rem;margin-top:20px;margin-bottom:10px;color:#555}main p{margin-bottom:15px;text-align:justify;font-size:1.1rem}main img{display:block;margin:30px auto;max-width:100%;height:auto;border-radius:8px;box-shadow:0 4px 8px rgba(0,0,0,0.1)}.click-word{cursor:pointer;border-bottom:1px dotted #999;transition:background-color 0.2s}.click-word:hover{background-color:var(--highlight-color);color:#000;border-bottom-style:solid}#translation-tooltip{position:absolute;background:rgba(50,50,50,0.95);color:#fff;padding:8px 15px;border-radius:6px;font-size:14px;z-index:2000;display:none;box-shadow:0 4px 15px rgba(0,0,0,0.2);pointer-events:none;white-space:nowrap}#translation-tooltip::after{content:'';position:absolute;top:100%;left:50%;margin-left:-6px;border-width:6px;border-style:solid;border-color:rgba(50,50,50,0.95) transparent transparent transparent}.site-footer{background-color:var(--footer-bg);color:var(--footer-text);padding:40px 20px 20px;margin-top:auto;z-index:100;position:relative}.footer-content{max-width:1200px;margin:0 auto;display:flex;justify-content:space-between;flex-wrap:wrap;gap:30px;padding-bottom:30px;border-bottom:1px solid rgba(255,255,255,0.1)}.footer-section{flex:1;min-width:250px}.footer-section h4{color:#fff;font-size:1.1rem;margin-bottom:15px;position:relative;padding-bottom:8px}.footer-section h4::after{content:'';position:absolute;left:0;bottom:0;width:40px;height:2px;background-color:var(--accent-color)}.footer-section p{font-size:0.9rem;line-height:1.6;color:#d7ccc8;margin-bottom:10px}.footer-links li{margin-bottom:8px}.footer-links a{color:#d7ccc8;font-size:0.9rem;transition:0.3s}.footer-links a:hover{color:#fff;padding-left:5px}.footer-bottom{text-align:center;padding-top:20px;font-size:0.85rem;color:rgba(255,255,255,0.6)}@media (max-width:768px){.container{flex-direction:column}aside{position:relative;width:100%;top:0;border-right:none;border-bottom:1px solid #ddd;padding:15px;max-height:fit-content;z-index:1}main{margin-left:0;padding:20px}.hamburger{display:flex}.nav-container{position:absolute;top:var(--nav-height);right:0;left:auto;width:auto;padding-right:15px;pointer-events:none}.nav-menu{flex-direction:column;gap:0;background:#fff;min-width:200px;max-height:80vh;overflow-y:auto;border-radius:8px;box-shadow:0 8px 20px rgba(0,0,0,0.15);padding:5px 0;opacity:0;visibility:hidden;transform:translateY(-10px) scale(0.95);transform-origin:top right;transition:all 0.3s,visibility 0.3s;pointer-events:auto}.nav-menu.active{opacity:1;visibility:visible;transform:translateY(0) scale(1)}.nav-item{width:100%;text-align:left;border-bottom:none}.nav-link{line-height:40px;padding:0 20px;font-size:0.95rem}.nav-link:hover{background-color:#f5f5f5;color:var(--primary-color)}.dropdown{position:static;box-shadow:none;opacity:1;visibility:visible;transform:none;background-color:#fafafa;display:none;padding-left:10px;max-height:none;overflow-y:visible}.nav-item.open>.dropdown{display:block}.dropdown li a{border-bottom:none;padding:8px 20px;font-size:0.85rem}.dropdown li.has-submenu.submenu-open>.submenu{display:block;border-left:2px solid #ddd}.footer-content{flex-direction:column;gap:20px}}