:root {
    --alert-radius: 0.625rem;
    --alert-shadow: 0 18px 45px rgba(0, 0, 0, 0.18);
}

.alert-banner {
    display: flex;
    align-items: center;
    gap: 0.65rem;
    padding: 0.85rem 2.75rem 0.85rem 1rem;
    border-radius: var(--alert-radius);
    border: 1px solid transparent;
    font-size: 0.95rem;
    font-weight: 500;
    line-height: 1.4;
    box-shadow: var(--alert-shadow);
    max-width: min(90vw, 28.75rem);
    position: relative;
    background: #f5f5f5;
    color: #1f2937;
}

.alert-icon {
    font-size: 1.15rem;
    line-height: 1;
    flex-shrink: 0;
}

.alert-text {
    flex: 1;
    word-break: break-word;
}

.alert-close {
    position: absolute;
    top: 50%;
    right: 0.75rem;
    transform: translateY(-50%);
    border: none;
    background: none;
    color: inherit;
    font-size: 1.35rem;
    line-height: 1;
    cursor: pointer;
    opacity: 0.6;
    padding: 0;
    transition: opacity 0.2s ease;
}

.alert-close:hover {
    opacity: 1;
}

.alert--floating {
    position: fixed;
    top: 0.35rem;
    left: 50%;
    transform: translateX(-50%);
    z-index: 11000;
    animation: alert-slide-down 0.25s ease;
}

.alert--floating.alert-hiding {
    animation: alert-slide-up 0.25s ease forwards;
}

.alert--error {
    background: #fee2e2;
    border-color: #fca5a5;
    color: #b91c1c;
}

.alert--success {
    background: #dcfce7;
    border-color: #86efac;
    color: #166534;
}

.alert--info {
    background: #e0f2fe;
    border-color: #7dd3fc;
    color: #0c4a6e;
}

/* 主题切换提示 - 根据主题显示不同颜色 */
.alert--theme {
    background: #f5f5f5;
    border-color: #d4d4d4;
    color: #404040;
}

/* 深色主题 */
[data-theme="dark"] .alert--theme {
    background: #374151;
    border-color: #4b5563;
    color: #f3f4f6;
}

/* 蓝色主题 */
[data-theme="blue"] .alert--theme {
    background: #dbeafe;
    border-color: #93c5fd;
    color: #1e40af;
}

/* 紫色主题 */
[data-theme="purple"] .alert--theme {
    background: #ede9fe;
    border-color: #c4b5fd;
    color: #5b21b6;
}

/* 绿色主题 */
[data-theme="green"] .alert--theme {
    background: #dcfce7;
    border-color: #86efac;
    color: #166534;
}

@media (prefers-color-scheme: dark) {
    .alert--error {
        background: rgba(248, 113, 113, 0.15);
        border-color: rgba(239, 68, 68, 0.6);
        color: #fca5a5;
    }

    .alert--success {
        background: rgba(74, 222, 128, 0.17);
        border-color: rgba(34, 197, 94, 0.6);
        color: #bbf7d0;
    }

    .alert--info {
        background: rgba(96, 165, 250, 0.17);
        border-color: rgba(59, 130, 246, 0.6);
        color: #bfdbfe;
    }
}

@keyframes alert-slide-down {
    from {
        opacity: 0;
        transform: translate(-50%, -10px);
    }
    to {
        opacity: 1;
        transform: translate(-50%, 0);
    }
}

@keyframes alert-slide-up {
    from {
        opacity: 1;
        transform: translate(-50%, 0);
    }
    to {
        opacity: 0;
        transform: translate(-50%, -10px);
    }
}