* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: #f5f5f5;
    color: #333;
    overflow: hidden;
}

.app {
    display: flex;
    height: 100vh;
}

/* Dock 侧边栏 */
.sidebar {
    width: 64px;
    min-width: 64px;
    background: #1a1a2e;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    padding: 16px 0;
    overflow: hidden;
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: 8px;
    padding: 0 12px;
}

.nav-item {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    margin: 0 auto;
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    border-radius: 10px;
    transition: all 0.2s ease;
    position: relative;
}

.nav-item i {
    font-size: 22px;
}

.nav-item:hover {
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
}

.nav-item.active {
    background: rgba(74, 144, 217, 0.2);
    color: #4a90d9;
}

.nav-item.active::before {
    content: '';
    position: absolute;
    left: -12px;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 20px;
    background: #4a90d9;
    border-radius: 0 2px 2px 0;
}

/* Tooltip on hover */
.nav-item:hover::after {
    content: attr(title);
    position: absolute;
    left: 52px;
    background: rgba(0, 0, 0, 0.8);
    color: #fff;
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 13px;
    white-space: nowrap;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.2s;
    z-index: 100;
}

.nav-item:hover:hover::after {
    opacity: 1;
}

.sidebar-footer {
    padding: 0 12px;
}

.settings-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.05);
    border: none;
    color: rgba(255, 255, 255, 0.7);
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.2s;
}

.settings-btn i {
    font-size: 22px;
}

.settings-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
}

/* 内容区 */
.content {
    flex: 1;
    overflow-y: auto;
    height: 100vh;
}

.content-body {
    min-height: 100%;
}

.empty-state {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    color: #999;
    font-size: 15px;
}