:root {
    --primary-color: #e63946;
    --secondary-color: #a8dadc;
    --dark-color: #1d3557;
    --light-color: #f1faee;
    --accent-color: #457b9d;
    --transition: all 0.4s cubic-bezier(0.25, 0.8, 0.25, 1);
    --card-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
    --card-hover-shadow: 0 20px 40px rgba(231, 57, 70, 0.3);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 0;
    font-family: 'Montserrat', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
    color: var(--light-color);
    min-height: 100vh;
    overflow-x: hidden;
    line-height: 1.6;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 3rem;
}

.main-title {
    color: var(--light-color);
    text-align: center;
    margin-bottom: 3rem;
    font-weight: 300;
    letter-spacing: 3px;
    font-size: 2.5rem;
    text-transform: uppercase;
    position: relative;
    padding-bottom: 1rem;
}

.main-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100px;
    height: 3px;
    background: var(--primary-color);
}

/* 相册选择模块 */
.album-selection {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 3rem;
    margin-top: 3rem;
}

.album-card {
    background: rgba(29, 53, 87, 0.7);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--card-shadow);
    transition: var(--transition);
    cursor: pointer;
    position: relative;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    transform: translateY(0);
}

.album-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--card-hover-shadow);
    border-color: var(--primary-color);
}

.album-cover {
    height: 240px;
    background-size: cover;
    background-position: center;
    position: relative;
    transition: var(--transition);
}

.album-card:hover .album-cover {
    transform: scale(1.02);
}

.album-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(to top, rgba(0, 0, 0, 0.8), transparent);
    display: flex;
    align-items: flex-end;
    justify-content: center;
    padding: 2rem;
    opacity: 1;
    transition: var(--transition);
}

.album-info {
    padding: 2rem;
    text-align: center;
}

.album-title {
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--light-color);
    letter-spacing: 1px;
}

.album-date {
    font-size: 0.9rem;
    color: var(--secondary-color);
    letter-spacing: 1px;
}

/* 相册详情模块 */
.album-detail {
    animation: fadeIn 0.5s ease-out;
}

.back-button {
    background: rgba(69, 123, 157, 0.3);
    border: none;
    font-size: 1rem;
    color: var(--light-color);
    cursor: pointer;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
    padding: 0.8rem 1.5rem;
    border-radius: 30px;
    backdrop-filter: blur(5px);
}

.back-button:hover {
    background: rgba(69, 123, 157, 0.5);
    transform: translateX(-5px);
}

.detail-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 3rem;
}

.detail-title {
    font-size: 2.5rem;
    font-weight: 300;
    color: var(--light-color);
    margin: 0;
    letter-spacing: 2px;
    text-transform: uppercase;
}

.photo-grid {
    /* 将容器设置为网格布局 */
    display: grid;

    /* 定义网格布局的列宽，使用重复函数自动填充，最小宽度为460px，最大宽度为容器的1个分数单位 */
    grid-template-columns: repeat(auto-fill, minmax(45%, 1fr));

    /* 设置网格布局中行与列之间的间隔为2rem */
    gap: 2rem;
}

.photo-item {
    /* 设置元素的定位方式为相对定位，以便于在正常文档流中调整元素位置 */
    position: relative;

    /* 给元素添加圆角边框，半径为12像素，提升界面的柔和度和美观性 */
    border-radius: 12px;

    /* 设置元素内容区域外的样式，隐藏溢出的内容，确保内容不会显示出来 */
    overflow: hidden;

    /* 为元素添加阴影效果，使用变量--card-shadow定义阴影的样式 */
    box-shadow: var(--card-shadow);

    /* 设置元素过渡效果，使用变量--transition定义过渡的持续时间和属性 */
    transition: var(--transition);

    aspect-ratio: 4/3;

    /* 设置元素的背景颜色为半透明的蓝色调，使用rgba颜色值定义颜色和透明度 */
    background: rgba(29, 53, 87, 0.5);

    /* 设置元素的初始缩放比例为1，即原始大小，通常用于动画或交互效果 */
    transform: scale(1);

}

.photo-item:hover {
    transform: scale(1.03);
    box-shadow: var(--card-hover-shadow);
    z-index: 2;
}

.photo-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
    opacity: 0;
    transform: scale(0.95);
}

.photo-img.loaded {
    opacity: 1;
    transform: scale(1);
}

.loading-spinner {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 40px;
    height: 40px;
    border: 3px solid rgba(168, 218, 220, 0.3);
    border-radius: 50%;
    border-top-color: var(--secondary-color);
    animation: spin 1s ease-in-out infinite;
}

/* 图片预览模态框 */
.preview-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.95);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.preview-modal.active {
    opacity: 1;
    display: flex;
}

.modal-content {
    position: relative;
    max-width: 90%;
    max-height: 90%;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.modal-img {
    max-width: 100%;
    max-height: 80vh;
    object-fit: contain;
    border-radius: 8px;
    transform: scale(0.5);
    transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.3s ease;
    opacity: 0;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
}

.modal-img.active {
    transform: scale(1);
    opacity: 1;
}

.modal-tools {
    display: flex;
    gap: 1.5rem;
    margin-top: 2rem;
}

.tool-btn {
    background: rgba(230, 57, 70, 0.3);
    border: none;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
    color: white;
    font-size: 1.2rem;
    backdrop-filter: blur(5px);
}

.tool-btn:hover {
    background: rgba(230, 57, 70, 0.5);
    transform: scale(1.1);
}

.nav-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 60px;
    height: 60px;
    background: rgba(230, 57, 70, 0.3);
    border: none;
    border-radius: 50%;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    transition: var(--transition);
    z-index: 10;
    backdrop-filter: blur(5px);
}

.nav-btn:hover {
    background: rgba(230, 57, 70, 0.5);
    transform: translateY(-50%) scale(1.1);
}

.prev-btn {
    left: 30px;
}

.next-btn {
    right: 30px;
}

.close-modal {
    position: absolute;
    top: 40px;
    right: 40px;
    background: rgba(230, 57, 70, 0.3);
    border: none;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(5px);
}

.close-modal:hover {
    background: rgba(230, 57, 70, 0.5);
    transform: rotate(90deg);
}

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

@keyframes spin {
    to {
        transform: translate(-50%, -50%) rotate(360deg);
    }
}

/* 雪花背景效果 */
.snowflake {
    position: fixed;
    color: white;
    font-size: 1em;
    user-select: none;
    pointer-events: none;
    opacity: 0.8;
    text-shadow: 0 0 10px rgba(230, 57, 70, 0.5);
    animation: fall linear infinite;
    z-index: -1;
}

@keyframes fall {
    to {
        transform: translateY(100vh);
    }
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .container {
        padding: 2rem;
    }

    .album-selection {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
        gap: 2rem;
    }

    .photo-grid {
        grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    }
}

@media (max-width: 768px) {
    .container {
        padding: 1.5rem;
    }

    .main-title {
        font-size: 2rem;
        margin-bottom: 2rem;
    }

    .album-selection {
        grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
        gap: 1.5rem;
    }

    .album-cover {
        height: 200px;
    }

    .detail-title {
        font-size: 2rem;
    }

    .photo-grid {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
        gap: 1.5rem;
    }

    .tool-btn, .close-modal {
        width: 45px;
        height: 45px;
        font-size: 1.1rem;
    }

    .nav-btn {
        width: 50px;
        height: 50px;
        font-size: 1.3rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 1rem;
    }

    .main-title {
        font-size: 1.8rem;
    }

    .album-selection {
        grid-template-columns: 1fr;
    }

    .detail-title {
        font-size: 1.8rem;
    }

    .photo-grid {
        grid-template-columns: 1fr;
    }
}