:root {
    --primary-color: #0078d4;
    --secondary-color: #f3f2f1;
    --text-color: #333333;
    --border-radius: 4px;
    --card-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    --card-shadow-hover: 0 12px 30px rgba(0, 0, 0, 0.12);
}

.age-rating-description {
    margin: 20px 0;
    padding: 15px;
    background-color: #f8f9fa;
    border-left: 4px solid #0d6efd;
    border-radius: 4px;
}

.age-rating-description h4 {
    margin-top: 0;
    color: #0d6efd;
    font-size: 1.2rem;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: var(--text-color);
    background-color: #faf9f8;
    overflow-x: hidden;
    padding-top: 56px;
}

/* AppStore风格入场动画 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.blur-bg {
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    background-color: rgba(255, 255, 255, 0.7);
    border-radius: var(--border-radius);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.card {
    border: none;
    border-radius: 16px;
    overflow: hidden;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    box-shadow: var(--card-shadow);
    animation: fadeInUp 0.6s ease-out forwards;
    opacity: 0;
}

/* 卡片交错动画延迟 */
.card:nth-child(2n) {
    animation-delay: 0.1s;
}
.card:nth-child(3n) {
    animation-delay: 0.2s;
}

.card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: var(--card-shadow-hover);
    z-index: 10;
}

.btn-primary {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
    border-radius: 20px;
    transition: all 0.3s ease;
    transform: translateZ(0);
}

.btn-primary:hover {
    background-color: #005a9e;
    border-color: #005a9e;
    transform: translateY(-2px);
}

.btn-primary:active {
    transform: translateY(1px) scale(0.98);
}

.navbar {
    padding: 0.75rem 1rem;
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1030;
}

.navbar.scrolled {
    background-color: rgba(255, 255, 255, 0.95);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.nav-link {
    color: var(--text-color);
    padding: 0.5rem 1rem;
}

.nav-link:hover {
    color: var(--primary-color);
}

.form-control {
    border-radius: var(--border-radius);
}

/* 年龄分级 SVG 样式 */
.age-rating {
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.age-rating svg {
    width: 20px;
    height: 20px;
}

/* 骨架屏加载动画 */
.skeleton-chart {
    width: 400px;
    height: 200px;
    background: #f0f0f0;
    border-radius: 4px;
    position: relative;
    overflow: hidden;
}

@keyframes shimmer {
    0% { background-position: -468px 0 }
    100% { background-position: 468px 0 }
}

.skeleton-chart::after {
    content: "";
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    transform: translateX(-100%);
    background: linear-gradient(90deg, rgba(255,255,255,0) 0%, rgba(255,255,255,0.2) 20%, rgba(255,255,255,0.5) 60%, rgba(255,255,255,0) 100%);
    animation: shimmer 2s infinite;
}