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

/* 全局变量定义 */
:root {
    --color-bg: #000000;
    --color-text: #FFFFFF;
    --color-text-muted: #E0E0E0;
    --color-accent: #D4AF37;
    --font-primary: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    --font-heading: 'Helvetica Now', 'Avenir Next', var(--font-primary);
}

/* 基础重置与排版 */
html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    background-color: var(--color-bg);
    color: var(--color-text);
    font-family: var(--font-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    scroll-behavior: smooth;
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 300;
    letter-spacing: 0.05em;
}

/* 自定义滚动条 */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
    background: #111;
}

::-webkit-scrollbar-thumb {
    background: #333;
    border-radius: 3px;
    transition: background 0.3s;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-accent);
}

/* 导航链接动效 */
.nav-item {
    position: relative;
    padding-bottom: 2px;
}

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

.nav-item:hover::after,
.nav-item.active::after {
    width: 100%;
}

/* 动画关键帧 */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes slideInRight {
    from { opacity: 0; transform: translateX(30px); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes pulse-subtle {
    0%, 100% { opacity: 0.8; }
    50% { opacity: 1; }
}

/* 通用动画类 */
.animate-fade-in {
    animation: fadeIn 1.2s cubic-bezier(0.16, 1, 0.3, 1) forwards;
    opacity: 0;
}

.animate-slide-in-right {
    animation: slideInRight 1s ease-out forwards;
    opacity: 0;
}

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

/* 图像交互效果 */
.img-zoom-container {
    overflow: hidden;
    position: relative;
}

.img-zoom-container img {
    transition: transform 0.7s cubic-bezier(0.25, 0.46, 0.45, 0.94), opacity 0.3s ease;
    will-change: transform;
}

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

/* 遮罩层渐变 */
.gradient-overlay-bottom {
    background: linear-gradient(to top, rgba(0,0,0,0.9) 0%, rgba(0,0,0,0.4) 30%, rgba(0,0,0,0) 100%);
}

/* 移动端菜单过渡 */
.mobile-menu {
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    transform: translateX(100%);
}

.mobile-menu.open {
    transform: translateX(0);
}

/* 极简边框装饰 */
.border-accent-subtle {
    border-color: rgba(212, 175, 55, 0.3);
}

/* 文本工具类 */
.text-gold {
    color: var(--color-accent);
}

.font-light-heading {
    font-weight: 300;
}