/* 引入思源黑体风格字体 */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;400;500;700&display=swap');

:root {
    --color-bg-primary: #F5F5F3; /* 燕麦色/米白背景 */
    --color-text-primary: #1A1A1A;
    --color-text-secondary: #555555;
    --font-primary: 'Noto Sans SC', sans-serif;
}

html {
    scroll-behavior: smooth;
    font-family: var(--font-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    margin: 0;
    padding: 0;
    overflow-x: hidden;
}

/* 导航栏：玻璃拟态效果 */
.glass-nav {
    background: rgba(245, 245, 243, 0.9);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.03);
    transition: all 0.3s ease;
}

/* 导航链接：简约下划线动画 */
.nav-link {
    position: relative;
    text-decoration: none;
    color: var(--color-text-primary);
    padding-bottom: 4px;
}

.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 1px;
    bottom: 0;
    left: 0;
    background-color: var(--color-text-primary);
    transition: width 0.3s ease-in-out;
}

.nav-link:hover::after {
    width: 100%;
}

/* 图片容器：悬停放大 */
.img-hover-zoom {
    overflow: hidden;
    position: relative;
}

.img-hover-zoom img {
    transition: transform 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    width: 100%;
    height: 100%;
    object-fit: cover;
}

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

/* 遮罩层文字 */
.hover-overlay {
    background: rgba(255, 255, 255, 0.3);
    opacity: 0;
    transition: opacity 0.4s ease;
}

.img-hover-zoom:hover .hover-overlay {
    opacity: 1;
}

/* 动画关键帧 */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(40px); }
    to { opacity: 1; transform: translateY(0); }
}

/* 通用动画类 */
.animate-fade-in {
    animation: fadeIn 1.5s ease-out forwards;
}

.animate-slide-up {
    opacity: 0; /* 初始隐藏 */
    animation: slideUp 1s cubic-bezier(0.2, 0.8, 0.2, 1) forwards;
}

.delay-200 { animation-delay: 0.2s; }
.delay-400 { animation-delay: 0.4s; }
.delay-600 { animation-delay: 0.6s; }

/* 极简滚动条 */
::-webkit-scrollbar {
    width: 4px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: #CCCCCC;
    border-radius: 2px;
}
::-webkit-scrollbar-thumb:hover {
    background: #999999;
}

/* 锚点定位偏移（避开固定导航栏） */
.scroll-offset {
    scroll-margin-top: 100px;
}

/* 移动端优化 */
@media (max-width: 768px) {
    .glass-nav {
        background: rgba(245, 245, 243, 0.95);
    }
}

/* 渐进式图片加载效果 */
.blur-up {
    filter: blur(10px);
    transition: filter 0.5s ease-out;
}
.blur-up.loaded {
    filter: blur(0);
}