/* 引入Google Fonts: Playfair Display */
@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:ital,wght@0,400;0,500;0,600;1,400&display=swap');

/* 全局变量与基础设置 */
:root {
    --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
    --color-bg: #ffffff;
    --color-text: #333333;
}

body {
    /* 默认正文使用无衬线字体 */
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    background-color: var(--color-bg);
    color: var(--color-text);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

/* 标题字体 - 优雅衬线体 */
.font-serif-display {
    font-family: 'Playfair Display', 'Source Han Serif CN', 'Noto Serif SC', 'Songti SC', serif;
}

/* 极简滚动条 */
::-webkit-scrollbar {
    width: 4px;
    height: 4px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: #d1d5db;
    border-radius: 2px;
}
::-webkit-scrollbar-thumb:hover {
    background: #9ca3af;
}

/* 视差滚动工具类 */
.parallax-bg {
    background-attachment: fixed;
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
}

/* 图片交互容器 */
.group-hover-zoom {
    overflow: hidden;
    position: relative;
    /* 消除图片底部默认间隙 */
    display: block; 
}

.group-hover-zoom img {
    transition: transform 1.2s var(--ease-out-expo), filter 0.5s ease;
    will-change: transform;
}

.group-hover-zoom:hover img {
    transform: scale(1.05);
}

/* 文本遮罩层过渡 */
.overlay-content {
    transition: opacity 0.5s ease, transform 0.5s var(--ease-out-expo);
    opacity: 0;
    transform: translateY(10px);
}

.group-hover-zoom:hover .overlay-content {
    opacity: 1;
    transform: translateY(0);
}

/* 通用动画关键帧 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-fade-in {
    opacity: 0; /* 配合JS IntersectionObserver使用 */
    animation-fill-mode: forwards;
}

.is-visible {
    animation: fadeInUp 1s var(--ease-out-expo) forwards;
}

/* 延时工具类 */
.delay-100 { animation-delay: 100ms; }
.delay-200 { animation-delay: 200ms; }
.delay-300 { animation-delay: 300ms; }

/* 文本选区美化 */
::selection {
    background-color: #f3f4f6;
    color: #1f2937;
}

/* 移动端菜单过渡 */
.mobile-menu-transition {
    transition: transform 0.4s var(--ease-out-expo), opacity 0.3s ease;
}