/* --- 基础重置与暗黑主题变量 --- */
:root {
    --bg-color: #0a0a0a;       /* 极暗的深空灰底色 */
    --text-main: #f5f5f5;      /* 柔和的亮白色文字 */
    --text-muted: #c2c2c2;     /* 辅助文字灰色 */
    --card-bg-1: #0a0a0a;      /* 卡片1底色 */
    --card-bg-2: #242424;      /* 卡片2底色 */
    --card-bg-3: #2e2e2e;      /* 卡片3底色 */
}
h2 {
    /* ... 之前的代码 ... */
    hyphens: auto;           /* 自动加连字符（如果浏览器支持） */
    overflow-wrap: break-word; /* 强制长单词换行，不破坏布局 */
}
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

img {
    display: block; /* 消除底部的幽灵间隙 */
    width: 100%;
    height: auto;
}   

body {
    font-family: 'Manrope', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    -webkit-font-smoothing: antialiased;
     margin: 0;
    padding: 0;
}

/* --- 页面骨架 --- */
.container {
    max-width: 1300px;
    margin: 0 auto;
    padding: 0 5%;
}

/* --- 首屏介绍区 (Hero) --- */
.hero {
    min-height: 80vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.hero p.tag {
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.2em;
    font-size: 0.9rem;
    margin-bottom: 1rem;
    font-weight: 600;
}

.hero h1 {
    font-size: clamp(3rem, 6vw, 6rem); /* 响应式巨型字体 */
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.03em;
    max-width: 800px;
}

/* --- 核心魔法：层叠卡片堆 (The Stacking Cards) --- */
.projects-stack {
    padding-bottom: 30vh; /* 底部留白，确保最后一张卡片能划过去 */
    display: flex;
    flex-direction: column;
    gap: 80px; /* 滚动前卡片之间的间距 */
}

.project-card {
    /* 核心 CSS 魔法：吸顶效果 */
    position: sticky;
    
    height: 75vh;
    border-radius: 32px;
    padding: 3rem;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    
    /* 边缘光泽与阴影，打造空间立体感 */
    border: 1px solid rgba(255, 255, 255, 0.05);
    box-shadow: 0 -20px 40px rgba(0, 0, 0, 0.6); 
    
    transform-origin: top center;
    overflow: hidden;
    
    /* 背景设置（为照片准备） */
    background-size: cover;
    background-position: center;
}

/* 卡片阶梯式层叠控制 */
.card-1 { 
    
    
    top: 10vh; 
    background-color: var(--card-bg-1); 
    z-index: 1;
    background-image: linear-gradient(rgba(0,0,0,0.5), rgba(0,0,0,0.5)), 
    url('images/qinghai1.webp');
    background-size:cover;
    
    background-repeat:no-repeat;
    transform:translateZ(0);
    background-clip:padding-box;
    overflow: hidden;
}
.card-2 { 
    top: calc(10vh + 30px); /* 露出上面卡片 30px 的边缘 */
    background-color: var(--card-bg-2); 
    z-index: 2; 
     background-image: linear-gradient(rgba(0,0,0,0.5), rgba(0,0,0,0.5)), 
    url('images/japan1.webp');
    background-size:cover;
    background-repeat:no-repeat;
    transform:translateZ(0);
    background-clip:padding-box;
    overflow: hidden;
}
.card-3 { 
    top: calc(10vh + 60px); /*每加一个卡片+30px*/
    background-color: var(--card-bg-3); 
    z-index: 3; 
    background-image: linear-gradient(rgba(0,0,0,0.5), rgba(0,0,0,0.5)), 
    url('images/chongqing1.webp');
     background-size:cover;
    background-repeat:no-repeat;
    transform:translateZ(0);
    background-clip:padding-box;
    overflow: hidden;
}
.card-4 { 
    top: calc(10vh + 90px); /*每加一个卡片+30px*/
    background-color: var(--card-bg-3); 
    z-index: 4; 
    background-image: linear-gradient(rgba(0,0,0,0.5), rgba(0,0,0,0.5)), 
    url('images/lijiang1.webp');
     background-size:cover;
    background-repeat:no-repeat;
    transform:translateZ(0);
    background-clip:padding-box;
    overflow: hidden;
}
.card-5 { 
    top: calc(10vh + 120px); /*每加一个卡片+30px*/
    background-color: var(--card-bg-3); 
    z-index: 5; 
background-image: linear-gradient(rgba(0,0,0,0.5), rgba(0,0,0,0.5)), 
    url('images/me.webp');
     background-size:cover;
    background-repeat:no-repeat;
    transform:translateZ(0);
    background-clip:padding-box;
    overflow: hidden;
    
}

/* --- 卡片内部排版 --- */
.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.card-year {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-muted);
}

.card-content h2 {
    font-size: 3rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    margin-bottom: 0.5rem;
}

.card-content p {
    font-size: 1.2rem;
    color: var(--text-muted);
    max-width: 500px;
}

/* 交互按钮 */
.btn-view {
    display: inline-block;
    margin-top: 2rem;
    padding: 1rem 2rem;
    border-radius: 50px;
    background: #fff;
    color: #000;
    text-decoration: none;
    font-weight: 600;
    transition: transform 0.3s ease;
}

.project-card:hover .btn-view {
    transform: translateX(15px);
}


/* --- 📱 移动端响应式适配 (专治文字挤压) --- */
@media (max-width: 768px) {
    /* 1. 缩小卡片内边距：上下留 2rem，左右留 1.5rem，给文字释放横向空间 */
    .project-card {
        padding: 2rem 1.5rem; 
    }

    /* 2. 动态缩小卡片标题：使用 clamp 函数让字体在 2.5rem 到 3.5rem 之间丝滑缩放 */
    .card-content h2 {
        font-size: clamp(2.5rem, 12vw, 3.5rem); 
        line-height: 1.1;
        word-break: break-word; /* 加上这个保险，万一有个超长单词会自动换行，不会撑爆屏幕 */
    }

    /* 3. 顺手把卡片顶部的参数文字（比如 25Q2）也稍微调小一点，显得更精致 */
    .card-year {
        font-size: 1rem;
    }

    /* 4. 首屏的 Hero 大字也跟着收缩一下，保持整体比例和谐 */
    .hero h1 {
        font-size: clamp(2.5rem, 10vw, 4rem);
    }
}