/* =========================================
   全局初始化与 Apple 核心美学
   ========================================= */
html {
    scroll-behavior: smooth;
    scroll-padding-top: 118px;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
    background:
        linear-gradient(180deg, #ffffff 0%, #f5f5f7 42%, #eceef3 100%);
    color: #1d1d1f;
    min-height: 100vh;
}

/* =========================================
   复合毛玻璃顶栏 (Header & Nav)
   ========================================= */
.glass-header {
    position: sticky;
    top: 0;
    z-index: 100;
    width: 100%;
    background: rgba(255, 255, 255, 0.78);
    backdrop-filter: blur(24px) saturate(180%);
    -webkit-backdrop-filter: blur(24px) saturate(180%);
    border-bottom: 1px solid rgba(0, 0, 0, 0.06);
    box-shadow: 0 8px 28px rgba(20, 23, 28, 0.06);
}

.header-content {
    max-width: 1180px;
    margin: 0 auto;
    padding: 0.8rem 18px 0.35rem 18px;
    text-align: center;
}

.glass-header h1 {
    font-size: 1.36rem;
    font-weight: 750;
    letter-spacing: 0;
    line-height: 1.15;
}

.year-nav {
    display: flex;
    justify-content: center;
    gap: 8px;
    padding: 0.42rem 18px 0.68rem 18px;
    max-width: 1180px;
    margin: 0 auto;
    overflow-x: auto;
    scrollbar-width: none;
}

.year-nav::-webkit-scrollbar {
    display: none;
}

.year-tab {
    display: inline-block;
    flex: 0 0 auto;
    padding: 6px 13px;
    background: rgba(255, 255, 255, 0.72);
    color: #454549;
    text-decoration: none;
    font-size: 0.8rem;
    font-weight: 650;
    border-radius: 20px;
    border: 1px solid rgba(0, 0, 0, 0.06);
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.03);
    transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.year-tab:hover {
    background: #1d1d1f;
    border-color: #1d1d1f;
    color: #fff;
}

/* =========================================
   时间线区块布局 (Timeline Sections)
   ========================================= */
.year-section {
    max-width: 1180px;
    margin: 0 auto;
    padding: 16px 18px 32px 18px;
    content-visibility: auto;
    contain-intrinsic-size: 900px;
}

.year-title {
    font-size: 1.5rem;
    font-weight: 760;
    letter-spacing: 0;
    margin: 16px 0 14px 0;
    color: #1d1d1f;
    display: flex;
    align-items: center;
    gap: 10px;
}

.year-title::after {
    content: '';
    flex: 1;
    height: 1px;
    background: rgba(0, 0, 0, 0.06);
    margin-left: 10px;
}

.year-count {
    flex: 0 0 auto;
    padding: 4px 9px;
    border-radius: 999px;
    background: rgba(0, 0, 0, 0.045);
    color: #6e6e73;
    font-size: 0.75rem;
    font-weight: 650;
    line-height: 1;
}

.gallery-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(178px, 1fr));
    gap: 14px;
    padding: 8px 0;
}

.wallpaper-card {
    position: relative;
    border-radius: 14px;
    overflow: hidden;
    aspect-ratio: 9 / 16; 
    background-color: #e8e8ed;
    box-shadow:
        0 1px 1px rgba(0, 0, 0, 0.04),
        0 10px 28px rgba(25, 28, 33, 0.08);
    cursor: pointer;
    isolation: isolate;
    transition: transform 0.35s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.35s ease;
}

.wallpaper-card:hover {
    transform: translateY(-4px);
    box-shadow:
        0 2px 4px rgba(0, 0, 0, 0.06),
        0 16px 36px rgba(25, 28, 33, 0.16);
}

.wallpaper-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    background: linear-gradient(135deg, #eceef3, #dfe3ea);
    transition: transform 0.45s cubic-bezier(0.16, 1, 0.3, 1);
}

.wallpaper-card:hover img {
    transform: scale(1.035);
}

.card-download-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 36px 10px 10px;
    background: linear-gradient(to top, rgba(0,0,0,0.58), transparent);
    opacity: 0;
    transition: opacity 0.3s ease;
    text-align: center;
    color: white;
    font-size: 0.8rem;
    font-weight: 500;
}

.wallpaper-card:hover .card-download-overlay {
    opacity: 1;
}

/* =========================================
   沉浸式全屏预览弹窗与交互按钮
   ========================================= */
.modal {
    display: none;
    position: fixed;
    z-index: 200;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: black; 
    align-items: center;
    justify-content: center;
    overflow: hidden; 
}

.fullscreen-image {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain; 
    user-select: none;
    -webkit-user-drag: none;
}

/* 悬浮毛玻璃左右切换按钮 */
.nav-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(255, 255, 255, 0.12);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border: 1px solid rgba(255, 255, 255, 0.15);
    color: rgba(255, 255, 255, 0.85);
    font-size: 1.4rem;
    width: 54px;
    height: 54px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    z-index: 220;
    user-select: none;
}

.nav-btn:hover {
    background: rgba(255, 255, 255, 0.25);
    color: #fff;
    scale: 1.05;
}

.prev-btn { left: 32px; }
.next-btn { right: 32px; }

/* 全屏模式下的唯一元素：悬浮下载按钮 */
.modal-download-btn {
    position: absolute;
    bottom: 40px; 
    left: 50%;
    transform: translateX(-50%); 
    padding: 16px 32px;
    background: rgba(16, 16, 18, 0.72);
    backdrop-filter: blur(25px) saturate(180%);
    -webkit-backdrop-filter: blur(25px) saturate(180%);
    border: 1px solid rgba(255, 255, 255, 0.34);
    color: #ffffff;
    text-shadow: 0 1px 4px rgba(0, 0, 0, 0.65);
    border-radius: 50px; 
    text-align: center;
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    letter-spacing: 0.5px;
    box-shadow:
        0 10px 30px rgba(0, 0, 0, 0.35),
        inset 0 1px 0 rgba(255, 255, 255, 0.14);
    transition: all 0.3s ease;
    z-index: 210;
}

.modal-download-btn:hover {
    background: rgba(0, 0, 0, 0.82);
    box-shadow:
        0 10px 35px rgba(0, 0, 0, 0.45),
        inset 0 1px 0 rgba(255, 255, 255, 0.18);
    transform: translateX(-50%) translateY(-2px);
}

/* =========================================
   移动端极致纯净体验响应式微调
   ========================================= */
@media (max-width: 768px) {
    html {
        scroll-padding-top: 104px;
    }

    .header-content {
        padding: 0.72rem 12px 0.28rem 12px;
    }

    .glass-header h1 {
        font-size: 1.18rem;
    }

    .year-nav {
        justify-content: flex-start;
        gap: 8px;
        padding: 0.42rem 12px 0.62rem 12px;
    }

    .year-tab {
        padding: 6px 12px;
        font-size: 0.78rem;
    }

    .year-section {
        padding: 12px 10px 26px 10px;
        contain-intrinsic-size: 760px;
    }

    .year-title {
        font-size: 1.15rem;
        margin: 10px 0 10px 0;
        gap: 8px;
    }

    .year-title::after {
        margin-left: 6px;
    }

    .year-count {
        padding: 3px 7px;
        font-size: 0.68rem;
    }

    .gallery-container {
        grid-template-columns: repeat(3, minmax(0, 1fr));
        gap: 8px;
        padding: 4px 0;
    }

    .wallpaper-card {
        border-radius: 12px;
        box-shadow: 0 1px 8px rgba(20, 23, 28, 0.12);
    }

    .wallpaper-card:hover {
        transform: none;
    }

    .wallpaper-card:hover img {
        transform: none;
    }

    .card-download-overlay {
        display: none;
    }

    .nav-btn {
        width: 42px;
        height: 42px;
        font-size: 1.1rem;
        background: rgba(255, 255, 255, 0.08);
        border: 1px solid rgba(255, 255, 255, 0.05);
        opacity: 0.5; /* 降低移动端视觉存在感，优先手势 */
    }
    .prev-btn { left: 16px; }
    .next-btn { right: 16px; }
    
    .modal-download-btn {
        bottom: 30px;
        padding: 14px 28px;
        font-size: 0.95rem;
    }
}

@media (max-width: 360px) {
    html {
        scroll-padding-top: 86px;
    }

    .year-section {
        padding-left: 8px;
        padding-right: 8px;
    }

    .gallery-container {
        gap: 6px;
    }

    .wallpaper-card {
        border-radius: 10px;
    }
}


/* =========================================
   系统级深色模式 (Dark Mode) 支持
   跟随系统主题自动切换
   ========================================= */
@media (prefers-color-scheme: dark) {
    /* 1. 基础背景反转：采用 Apple 经典的深空黑与钛灰色 */
    body {
        background:
            linear-gradient(180deg, #111113 0%, #050506 48%, #000000 100%);
        color: #f5f5f7;
    }

    /* 2. 顶栏毛玻璃适配暗色系 */
    .glass-header {
        background: rgba(20, 20, 22, 0.78); /* 替换为 iOS 风格的深色毛玻璃底色 */
        border-bottom: 1px solid rgba(255, 255, 255, 0.08);
        box-shadow: 0 8px 28px rgba(0, 0, 0, 0.28);
    }

    /* 3. 导航 Tab 适配：降低亮色背景，使用柔和的浅灰字体 */
    .year-tab {
        background: rgba(255, 255, 255, 0.08);
        border-color: rgba(255, 255, 255, 0.08);
        color: #c7c7cc;
    }

    .year-tab:hover {
        background: #f5f5f7;
        border-color: #f5f5f7;
        color: #111113;
    }

    .wallpaper-card {
        box-shadow:
            0 1px 1px rgba(255, 255, 255, 0.04),
            0 12px 28px rgba(0, 0, 0, 0.5);
    }

    .wallpaper-card:hover {
        box-shadow:
            0 1px 2px rgba(255, 255, 255, 0.05),
            0 18px 38px rgba(0, 0, 0, 0.68);
    }

    @media (max-width: 768px) {
        .wallpaper-card {
            box-shadow: 0 1px 8px rgba(0, 0, 0, 0.42);
        }
    }

    /* 5. 卡片底色与阴影加深 */
    .wallpaper-card {
        background-color: #1c1c1e;
    }

    .wallpaper-card img {
        background: linear-gradient(135deg, #2c2c2e, #1c1c1e);
    }

    /* 4. 年份标题适配 */
    .year-title {
        color: #f5f5f7;
    }

    .year-title::after {
        background: rgba(255, 255, 255, 0.1); /* 标题右侧的分割线变更为半透明白色 */
    }

    .year-count {
        background: rgba(255, 255, 255, 0.1);
        color: #a1a1a6;
    }

    /* 注：全屏弹窗 (.modal) 及其内部按钮本就设计为全局暗色系叠加毛玻璃，
       因此在深色模式下无需修改，本身就是完美的 Dark Mode 体验。 */
}