/* floating-nav.css 完整版 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 外层容器：固定在右下角 */
.universal-nav {
    position: fixed;
    bottom: 24px;
    right: 24px;
    z-index: 9999;
    font-family: system-ui, 'Segoe UI', sans-serif;
}

/* FAB 圆形按钮 */
.unav-fab {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, #2c3e66, #1b2a48);
    border-radius: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 6px 20px rgba(0,0,0,0.4), 0 0 0 2px rgba(255,255,255,0.1) inset;
    color: white;
    font-size: 26px;
    transition: all 0.3s cubic-bezier(0.2, 0.9, 0.4, 1.1);
}
.unav-fab:hover {
    transform: scale(1.05);
    background: linear-gradient(135deg, #3c5a8c, #2c3e66);
    box-shadow: 0 10px 24px rgba(0,0,0,0.5);
}

/* 遮罩层 */
.unav-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.45);
    backdrop-filter: blur(6px);
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s;
    z-index: 1998;
}
.unav-overlay.active {
    opacity: 1;
    visibility: visible;
}

/* 侧滑抽屉菜单 */
.unav-drawer {
    position: fixed;
    top: 0;
    right: 0;
    width: 85%;
    max-width: 380px;
    height: 100%;
    background: rgba(20, 20, 30, 0.95);
    backdrop-filter: blur(12px);
    box-shadow: -8px 0 30px rgba(0,0,0,0.4);
    transform: translateX(100%);
    transition: transform 0.3s cubic-bezier(0.2, 0.9, 0.4, 1.1);
    display: flex;
    flex-direction: column;
    border-radius: 28px 0 0 28px;
    overflow: hidden;
    z-index: 1999;
}
.unav-drawer.open {
    transform: translateX(0);
}

/* 头部 */
.unav-header {
    padding: 24px 20px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.unav-header h3 {
    font-size: 1.4rem;
    background: linear-gradient(135deg, #fff, #aaccff);
    background-clip: text;
    -webkit-background-clip: text;
    color: transparent;
}
.unav-close {
    width: 36px;
    height: 36px;
    background: rgba(255,255,255,0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s;
    color: white;
    font-size: 18px;
}
.unav-close:hover {
    background: rgba(255,255,255,0.2);
    transform: rotate(90deg);
}

/* 内容区滚动 */
.unav-content {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
}

/* 工具网格卡片 */
.unav-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 14px;
}
.unav-item {
    background: rgba(30, 35, 48, 0.7);
    backdrop-filter: blur(4px);
    border-radius: 24px;
    padding: 16px 6px;
    text-align: center;
    text-decoration: none;
    transition: all 0.25s ease;
    border: 1px solid rgba(255,255,255,0.08);
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}
.unav-item i {
    font-size: 28px;
    margin-bottom: 10px;
    display: block;
    color: #7aa9ff;
    transition: all 0.2s;
}
.unav-item span {
    font-size: 0.75rem;
    font-weight: 500;
    color: #eef2ff;
    line-height: 1.3;
    display: block;
}
.unav-item:hover {
    background: rgba(50, 65, 90, 0.9);
    transform: translateY(-5px);
    border-color: rgba(100, 150, 255, 0.6);
    box-shadow: 0 14px 24px rgba(0,0,0,0.3);
}
.unav-item:hover i {
    color: white;
    transform: scale(1.05);
}
.unav-item.active-unav {
    background: #2c3e66;
    border-color: #4a9eff;
    box-shadow: 0 0 0 2px rgba(74,158,255,0.4);
}
.unav-item.active-unav i {
    color: #ffd966;
}

/* 分区标签 */
.unav-label {
    font-size: 0.7rem;
    letter-spacing: 1.5px;
    color: #bbccff;
    border-left: 3px solid #4a9eff;
    padding-left: 12px;
    margin-bottom: 16px;
}

/* 曲谱列表 */
.unav-song-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}
.unav-song-item {
    background: rgba(40, 45, 60, 0.7);
    backdrop-filter: blur(4px);
    border-radius: 18px;
    border: 1px solid rgba(255,255,255,0.05);
    padding: 12px 16px;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 12px;
    transition: 0.2s;
    color: #f0f3fa;
}
.unav-song-item i:first-child {
    width: 24px;
    color: #7aa9ff;
}
.unav-song-item .song-name {
    flex: 1;
}
.unav-song-item:hover {
    background: rgba(60, 70, 95, 0.9);
    transform: translateX(6px);
}
.unav-footer {
    text-align: center;
    font-size: 10px;
    color: #6c86a3;
    margin-top: 20px;
    padding-top: 12px;
    border-top: 1px solid rgba(255,255,255,0.08);
}