/* ===================================================
   Spark Studio Portal - Frontend Stylesheet v4
   设计灵感：NexusV 极简风格 + 蓝色 #3354AA 配色
   大圆角 / 充足留白 / 卡片网格 / 现代极简
   =================================================== */

/* ===== 设计变量：品牌色 / 三级灰阶 / 面 / 圆角 ===== */
:root {
    /* 品牌色 */
    --brand: #3354AA;
    --brand-dark: #2A478F;
    --brand-soft: rgba(51, 84, 170, 0.08);
    --brand-line: rgba(51, 84, 170, 0.20);

    /* 灰阶：全站只用三级，标题 / 正文 / 辅助 */
    --ink-1: #14171C;
    --ink-2: #545D6E;
    --ink-3: #6E7889;

    /* 面与描边 */
    --surface: #FFFFFF;
    --canvas: #FAFAFA;
    --line: rgba(16, 24, 40, 0.08);
    --line-soft: rgba(16, 24, 40, 0.06);

    /* 阴影 */
    --shadow-hover: 0 10px 30px rgba(51, 84, 170, 0.10);

    /* 圆角 */
    --radius-card: 20px;
    --radius-media: 14px;
    --radius-btn: 12px;
    --radius-pill: 100px;
}

/* ===== Reset ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text",
                 "Helvetica Neue", "PingFang SC", "Hiragino Sans GB",
                 "Source Han Sans CN", "Noto Sans CJK SC",
                 "WenQuanYi Micro Hei", "Microsoft Yahei", sans-serif;
    font-size: 16px;
    background-color: var(--canvas);
    color: var(--ink-1);
    line-height: 1.6;
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display",
                 "Helvetica Neue", "PingFang SC", "Hiragino Sans GB",
                 "Microsoft Yahei", sans-serif;
    font-weight: 700;
    color: var(--ink-1);
    letter-spacing: -0.02em;
}

a {
    color: var(--brand);
    text-decoration: none;
    transition: color 0.2s ease, opacity 0.2s ease;
}

a:hover {
    opacity: 0.75;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* ===== 容器 ===== */
.container {
    max-width: 1080px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== 页头 Header ===== */
#header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--line-soft);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 10px;
}

.site-logo img {
    height: 32px;
    width: auto;
}

#logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--ink-1);
    letter-spacing: -0.02em;
}

#logo:hover {
    opacity: 1;
    color: var(--brand);
}

.header-description {
    display: none;
}

#nav-menu {
    display: flex;
    align-items: center;
    gap: 4px;
    list-style: none;
}

#nav-menu a {
    display: block;
    padding: 8px 16px;
    color: var(--ink-2);
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: 8px;
    transition: background 0.2s ease, color 0.2s ease;
}

#nav-menu a:hover {
    background: var(--brand-soft);
    color: var(--brand);
    opacity: 1;
}

/* 当前区块导航项：底部品牌色圆点指示 */
#nav-menu a {
    position: relative;
}

#nav-menu a.current {
    background: var(--brand-soft);
    color: var(--brand);
    opacity: 1;
}

#nav-menu a.current::after {
    content: '';
    position: absolute;
    left: 50%;
    bottom: 2px;
    width: 4px;
    height: 4px;
    border-radius: 50%;
    background: var(--brand);
    transform: translateX(-50%);
}

/* 移动端汉堡菜单 */
.menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    flex-direction: column;
    gap: 4px;
}

.menu-toggle span {
    width: 22px;
    height: 2px;
    background: var(--ink-1);
    border-radius: 2px;
    transition: all 0.3s ease;
}

/* ===== Hero 首屏区域 ===== */
.hero {
    position: relative;
    overflow: hidden;
    padding: 104px 24px 72px;
    text-align: center;
    background: var(--canvas);
}

/* 品牌光晕：两团柔和径向渐变，给首屏一个视觉锚点 */
.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(900px 560px at 50% -10%, rgba(51, 84, 170, 0.22), rgba(51, 84, 170, 0) 70%),
        radial-gradient(620px 380px at 85% 12%, rgba(118, 148, 255, 0.18), rgba(118, 148, 255, 0) 72%),
        radial-gradient(520px 320px at 12% 30%, rgba(51, 84, 170, 0.10), rgba(51, 84, 170, 0) 70%);
    pointer-events: none;
}

.hero .container {
    position: relative;
    z-index: 1;
}

.hero-inner {
    max-width: 720px;
    margin: 0 auto;
}

.hero h1 {
    font-size: clamp(2.25rem, 5.2vw, 3.5rem);
    color: var(--ink-1);
    margin-bottom: 0.45em;
    line-height: 1.12;
    letter-spacing: -0.035em;
    font-weight: 800;
}

/* 标题关键字：品牌渐变文字，与背景光晕呼应 */
.hero h1 .grad {
    background: linear-gradient(120deg, var(--brand) 20%, #7694FF 85%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
}

.hero-subtitle {
    color: var(--ink-2);
    font-size: clamp(1.0625rem, 1.6vw, 1.25rem);
    max-width: 600px;
    margin: 0 auto 2.2em;
    line-height: 1.7;
}

/* 搜索框样式 */
.hero-search {
    max-width: 560px;
    margin: 0 auto 1.5em;
    position: relative;
}

.hero-search-input {
    width: 100%;
    padding: 16px 56px 16px 20px;
    font-size: 0.9375rem;
    border: 1px solid var(--line);
    border-radius: 16px;
    background: var(--surface);
    color: var(--ink-1);
    outline: none;
    box-shadow: 0 1px 2px rgba(16, 24, 40, 0.04), 0 8px 24px rgba(51, 84, 170, 0.06);
    transition: all 0.2s ease;
    font-family: inherit;
}

.hero-search-input:focus {
    border-color: var(--brand);
    background: var(--surface);
    box-shadow: 0 0 0 4px rgba(51, 84, 170, 0.12);
}

.hero-search-input::placeholder {
    color: var(--ink-3);
}

.hero-search-btn {
    position: absolute;
    right: 8px;
    top: 50%;
    transform: translateY(-50%);
    width: 40px;
    height: 40px;
    border: none;
    border-radius: var(--radius-btn);
    background: var(--brand);
    color: #FFF;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s ease;
    font-size: 1.1rem;
}

.hero-search-btn:hover {
    background: var(--brand-dark);
}

/* 快速操作芯片 */
.hero-chips {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 1.5em;
}

.hero-chip {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 18px;
    border: 1px solid var(--line);
    border-radius: var(--radius-pill);
    background: var(--surface);
    color: var(--ink-2);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
}

.hero-chip:hover {
    border-color: var(--brand);
    color: var(--brand);
    opacity: 1;
    background: var(--brand-soft);
}

/* ===== 循环条幅：首尾无缝横向滚动 ===== */
.banner-strip {
    position: relative;
    background: var(--surface);
    border-bottom: 1px solid var(--line-soft);
    padding: 20px 0;
    overflow: hidden;
    cursor: grab;
    /* 横向拖拽由脚本接管，纵向仍交给页面滚动 */
    touch-action: pan-y;
    /* 两端淡出，避免元素被硬生生截断 */
    -webkit-mask-image: linear-gradient(90deg, transparent, #000 8%, #000 92%, transparent);
    mask-image: linear-gradient(90deg, transparent, #000 8%, #000 92%, transparent);
}

/* 拖拽位移层：与 track 的自动滚动各管一层 transform，互不干扰 */
.banner-viewport {
    transition: transform 0.3s ease;
    will-change: transform;
}

.banner-viewport.is-dragging {
    transition: none;
}

.banner-track {
    display: flex;
    align-items: center;
    width: max-content;
    animation: banner-scroll var(--banner-duration, 30s) linear infinite;
    will-change: transform;
}

/* 没有可显示的条幅时（接口异常或后台未添加），整条隐藏，避免出现空条 */
.banner-strip.is-empty {
    display: none;
}

/* 鼠标移入暂停，方便看清与点击 */
.banner-strip:hover .banner-track,
.banner-strip.is-dragging .banner-track {
    animation-play-state: paused;
}

.banner-strip.is-dragging {
    cursor: grabbing;
}

.banner-item {
    flex: 0 0 auto;
    margin-right: 20px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    height: 56px;
    padding: 0 22px;
    background: var(--canvas);
    border: 1px solid var(--line);
    border-radius: var(--radius-media);
    user-select: none;
    -webkit-user-drag: none;
    transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.banner-item img {
    height: 28px;
    width: auto;
    max-width: 160px;
    object-fit: contain;
    -webkit-user-drag: none;
    /* 图片加载完成后由脚本加上 .is-loaded 淡入 */
    opacity: 0;
    transition: opacity 0.4s ease, transform 0.2s ease;
}

.banner-item img.is-loaded {
    opacity: 1;
}

a.banner-item:hover {
    border-color: var(--brand-line);
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
    opacity: 1;
}

a.banner-item:hover img {
    transform: scale(1.04);
}

/* 位移一份内容的宽度（前台渲染了两份），实现首尾无缝衔接 */
@keyframes banner-scroll {
    from { transform: translateX(0); }
    to   { transform: translateX(-50%); }
}

/* 尊重系统的「减少动态效果」偏好 */
@media (prefers-reduced-motion: reduce) {
    .banner-track {
        animation: none;
    }
}

@media (max-width: 640px) {
    .banner-item {
        height: 48px;
        padding: 0 16px;
    }
    .banner-item img {
        height: 24px;
    }
}

/* ===== Section 通用 ===== */
.section {
    padding: 64px 0;
}

.section-alt {
    background: #FFF;
}

.section-title {
    text-align: center;
    margin-bottom: 48px;
}

.section-title h2 {
    font-size: clamp(1.5rem, 2.6vw, 2.125rem);
    color: var(--ink-1);
    margin-bottom: 0.35em;
    letter-spacing: -0.02em;
    font-weight: 800;
}

/* 区块 eyebrow：小号品牌色引导标签，与 Hero 呼应 */
.section-title .eyebrow {
    display: inline-block;
    color: var(--brand);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    margin-bottom: 10px;
}

.section-title .section-subtitle {
    color: var(--ink-3);
    font-size: 0.9375rem;
    margin-bottom: 0;
}

/* ===== 产品卡片网格 ===== */
.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}

.product-card {
    padding: 28px;
    border: 1px solid var(--line-soft);
    border-radius: var(--radius-card);
    background: var(--surface);
    transition: all 0.25s ease;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.product-card:hover {
    border-color: var(--brand-line);
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}

.product-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-media);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.875rem;
    color: #FFF;
    background: linear-gradient(135deg, #4A6BC4, var(--brand));
    box-shadow: 0 4px 12px rgba(51, 84, 170, 0.22);
    flex-shrink: 0;
}

.product-name {
    font-size: 1.125rem;
    margin: 0;
}

.product-name a {
    color: var(--ink-1);
}

.product-name a:hover {
    color: var(--brand);
    opacity: 1;
}

.product-desc {
    color: var(--ink-2);
    font-size: 0.875rem;
    line-height: 1.6;
    flex: 1;
}

/* ===== 价值观卡片 ===== */
.values-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}

.value-card {
    padding: 28px;
    border: 1px solid var(--line-soft);
    border-radius: var(--radius-card);
    background: var(--surface);
    transition: all 0.25s ease;
}

.value-card:hover {
    border-color: var(--brand-line);
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}

/* 理念卡：编号上方一道品牌色短横线，区别于产品卡的实底图标 */
.value-card-icon {
    position: relative;
    padding-top: 14px;
    font-size: 1.5rem;
    color: var(--brand);
    margin-bottom: 12px;
    font-weight: 700;
    letter-spacing: 0.05em;
}

.value-card-icon::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 28px;
    height: 3px;
    border-radius: 3px;
    background: var(--brand);
}

.value-card h4 {
    font-size: 1.0625rem;
    color: var(--ink-1);
    margin-bottom: 8px;
}

.value-card p {
    color: var(--ink-2);
    font-size: 0.875rem;
    line-height: 1.65;
    margin: 0;
}

/* ===== 资讯列表 ===== */
.news-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.post {
    position: relative;
    overflow: hidden;
    padding: 24px;
    border: 1px solid var(--line-soft);
    border-radius: var(--radius-card);
    background: var(--surface);
    transition: all 0.25s ease;
}

/* 资讯卡：悬停时左侧展开一道品牌色竖条，与网格卡的上浮做出区分 */
.post::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: var(--brand);
    transform: scaleY(0);
    transform-origin: top;
    transition: transform 0.3s cubic-bezier(0.22, 0.61, 0.36, 1);
}

.post:hover::before {
    transform: scaleY(1);
}

.post:hover {
    border-color: var(--brand-line);
    box-shadow: var(--shadow-hover);
    transform: translateX(2px);
}

.post-title {
    font-size: 1.1875rem;
    margin-bottom: 8px;
}

.post-title a {
    color: var(--ink-1);
}

.post-title a:hover {
    color: var(--brand);
    opacity: 1;
}

.post-meta {
    display: flex;
    align-items: center;
    gap: 16px;
    color: var(--ink-3);
    font-size: 0.8125rem;
    list-style: none;
    margin-bottom: 12px;
}

.post-meta li {
    display: flex;
    align-items: center;
    gap: 4px;
}

.post-content {
    line-height: 1.65;
    word-wrap: break-word;
}

.post-content p {
    color: var(--ink-2);
    font-size: 0.9375rem;
    margin-bottom: 0;
}

.post-cover {
    position: relative;
    margin: 0 0 12px;
    border-radius: var(--radius-media);
    overflow: hidden;
}

.post-cover img {
    width: 100%;
    max-height: 280px;
    object-fit: cover;
    border-radius: var(--radius-media);
    transition: transform 0.45s ease;
}

/* 悬停时封面轻微放大，带一点「电影运镜」的味道 */
.post:hover .post-cover img {
    transform: scale(1.03);
}

.post-readmore {
    margin-top: 12px;
    font-size: 0.875rem;
}

.post-readmore a {
    color: var(--brand);
    font-weight: 500;
}

.news-empty {
    text-align: center;
    padding: 48px 0;
    color: var(--ink-3);
    font-size: 0.9375rem;
}

/* ===== 发展历程（横向时间线） ===== */
.timeline {
    display: flex;
    gap: 20px;
    position: relative;
    padding-top: 36px;
    padding-left: 8px;
    padding-right: 8px;
    /* 横向滚动 + 卡片吸附，条目多时左右滑动即可 */
    overflow-x: auto;
    scroll-snap-type: x proximity;
    padding-bottom: 12px;
    scrollbar-width: thin;
    scrollbar-color: var(--line) transparent;
    /* 时间轴主线画在容器背景上：滚动内容时主线保持不动 */
    background: linear-gradient(90deg, rgba(51, 84, 170, 0) 0%, rgba(51, 84, 170, 0.25) 6%, rgba(51, 84, 170, 0.25) 94%, rgba(51, 84, 170, 0) 100%) no-repeat;
    background-size: 100% 2px;
    background-position: 0 5px;
}

.timeline-item {
    position: relative;
    flex: 0 0 260px;
    scroll-snap-align: start;
    padding: 20px 18px 18px;
    border: 1px solid var(--line-soft);
    border-radius: var(--radius-card);
    background: var(--surface);
    transition: border-color 0.25s ease, box-shadow 0.25s ease, transform 0.25s ease;
}

.timeline-item:hover {
    border-color: var(--brand-line);
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}

/* 轴点：压在顶部主线上 */
.timeline-item::before {
    content: '';
    position: absolute;
    left: 24px;
    top: -39px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--brand);
    border: 3px solid var(--surface);
    box-shadow: 0 0 0 2px rgba(51, 84, 170, 0.2);
    transition: box-shadow 0.25s ease, transform 0.25s ease;
}

/* 悬停时轴点放大并泛出品牌色光晕 */
.timeline-item:hover::before {
    transform: scale(1.25);
    box-shadow: 0 0 0 4px rgba(51, 84, 170, 0.18), 0 0 14px rgba(51, 84, 170, 0.35);
}

.timeline-date {
    display: inline-block;
    color: var(--brand);
    font-size: 0.75rem;
    font-weight: 700;
    background: var(--brand-soft);
    padding: 3px 10px;
    border-radius: var(--radius-pill);
    margin-bottom: 10px;
}

.timeline-content {
    color: var(--ink-2);
    font-size: 0.875rem;
    line-height: 1.65;
}

.timeline-content strong {
    color: var(--ink-1);
    font-size: 0.9375rem;
    display: block;
    margin-bottom: 4px;
}

/* ===== 数字统计（深色品牌区块：全页张力担当） ===== */
#stats {
    /* 深海军蓝渐变底，官方站最经典的「一深到底」节奏点 */
    background: linear-gradient(135deg, #0E1B40 0%, #1A3572 58%, #21418A 100%);
    position: relative;
    overflow: hidden;
}

/* 深色区块内的星点微光：呼应「星火」意象 */
#stats::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(520px 300px at 82% 18%, rgba(118, 148, 255, 0.20), rgba(118, 148, 255, 0) 70%),
        radial-gradient(420px 260px at 10% 85%, rgba(118, 148, 255, 0.14), rgba(118, 148, 255, 0) 70%);
    pointer-events: none;
}

#stats .container {
    position: relative;
    z-index: 1;
}

#stats .section-title h2 {
    color: #FFF;
}

#stats .section-subtitle {
    color: rgba(255, 255, 255, 0.62);
}

#stats .section-title .eyebrow {
    color: #9DB4F5;
}

.stats-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 24px;
    max-width: 720px;
    margin: 0 auto;
}

/* 统计卡：深色底上的玻璃卡片 */
.stat-item {
    text-align: center;
    padding: 32px 16px 28px;
    border: 1px solid rgba(255, 255, 255, 0.14);
    border-radius: var(--radius-card);
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(4px);
    transition: all 0.25s ease;
}

.stat-item:hover {
    border-color: rgba(157, 180, 245, 0.55);
    background: rgba(255, 255, 255, 0.09);
    transform: translateY(-3px);
}

.stat-number {
    font-size: 3rem;
    color: #FFF;
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.03em;
    /* 等宽数字：滚动计数时各位数宽度稳定，不抖动 */
    font-variant-numeric: tabular-nums;
    text-shadow: 0 0 32px rgba(118, 148, 255, 0.45);
}

.stat-label {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.8125rem;
    margin-top: 8px;
    letter-spacing: 0.06em;
}

/* ===== 关于区域 ===== */
.about-content {
    max-width: 680px;
    margin: 0 auto;
    text-align: center;
}

.about-content p {
    color: var(--ink-2);
    font-size: 1rem;
    line-height: 1.85;
    margin-bottom: 1em;
    text-align: justify;
    text-justify: inter-ideograph;
    text-indent: 2em;
}

/* 引用块 */
.about-quote {
    margin: 2em 0;
    padding: 24px 28px;
    border-left: 4px solid var(--brand);
    background: rgba(51, 84, 170, 0.04);
    border-radius: 0 16px 16px 0;
    color: var(--ink-2);
    font-style: italic;
    text-align: left;
    line-height: 1.85;
    text-indent: 0;
    font-size: 0.9375rem;
}

.about-slogan {
    font-size: 1.375rem;
    color: var(--brand);
    font-style: italic;
    margin-top: 1.5em;
    text-align: center;
    letter-spacing: 0.03em;
    text-indent: 0;
    font-weight: 600;
}

/* ===== 页脚 Footer ===== */
#footer {
    padding: 48px 0 40px;
    text-align: center;
    color: var(--ink-3);
    font-size: 0.875rem;
    /* 白 → 淡品牌色的收尾渐变，给页面一个柔和的落点 */
    background: linear-gradient(180deg, var(--surface) 0%, var(--brand-soft) 100%);
    border-top: 1px solid var(--line-soft);
}

.footer-logo {
    margin-bottom: 16px;
}

.footer-logo img {
    height: 32px;
    margin: 0 auto;
}

.footer-copyright {
    margin-bottom: 8px;
    color: var(--ink-3);
}

.footer-links {
    margin: 12px 0;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 8px;
}

.footer-links a {
    color: var(--ink-3);
    font-size: 0.8125rem;
    padding: 4px 14px;
    border-radius: var(--radius-pill);
    border: 1px solid var(--line-soft);
    transition: all 0.2s ease;
}

.footer-links a:hover {
    border-color: var(--brand);
    color: var(--brand);
    opacity: 1;
}

.footer-icp a,
.footer-contact a {
    color: var(--ink-3);
}

.footer-icp a:hover,
.footer-contact a:hover {
    color: var(--brand);
    opacity: 1;
}

.footer-contact {
    margin-top: 6px;
}

/* ===== 社交媒体图标 ===== */
.footer-social {
    margin-top: 20px;
    display: flex;
    justify-content: center;
    gap: 10px;
}

.footer-social a {
    width: 40px;
    height: 40px;
    border: 1px solid var(--line);
    border-radius: var(--radius-btn);
    background: var(--surface);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.footer-social a:hover {
    border-color: var(--brand);
    background: var(--brand-soft);
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
    opacity: 1;
}

.footer-social svg {
    width: 18px;
    height: 18px;
    fill: var(--ink-3);
    transition: fill 0.2s ease;
}

.footer-social a:hover svg {
    fill: var(--brand);
}

/* ===== 回到顶部 ===== */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 44px;
    height: 44px;
    border: none;
    background: var(--ink-1);
    border-radius: var(--radius-media);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 999;
    font-size: 18px;
    color: #FFF;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: var(--brand);
}

/* ===== 骨架屏 ===== */
.skeleton {
    background: linear-gradient(90deg, #F0F0F0 25%, #E8E8E8 50%, #F0F0F0 75%);
    background-size: 200% 100%;
    animation: skeletonLoading 1.5s ease infinite;
    border-radius: 8px;
}

@keyframes skeletonLoading {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* ===== 响应式 ===== */
@media (max-width: 768px) {
    body {
        font-size: 15px;
    }

    .container {
        padding: 0 16px;
    }

    .menu-toggle {
        display: flex;
    }

    #nav-menu {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--surface);
        padding: 8px;
        border-bottom: 1px solid var(--line-soft);
        box-shadow: 0 8px 24px rgba(0, 0, 0, 0.06);
        gap: 0;
    }

    #nav-menu.open {
        display: flex;
    }

    #nav-menu a {
        padding: 12px 16px;
        border-radius: 10px;
    }

    .hero {
        padding: 64px 20px 48px;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-search-input {
        padding: 14px 50px 14px 16px;
        font-size: 0.875rem;
    }

    .hero-search-btn {
        width: 36px;
        height: 36px;
    }

    .section {
        padding: 40px 0;
    }

    .section-title {
        margin-bottom: 32px;
    }

    .section-title h2 {
        font-size: 1.375rem;
    }

    .products-grid,
    .values-grid {
        grid-template-columns: 1fr;
    }

    .product-card,
    .value-card {
        padding: 20px;
    }

    .post {
        padding: 18px;
    }

    .post-title {
        font-size: 1.0625rem;
    }

    .timeline {
        padding-top: 30px;
    }

    .timeline-item {
        flex-basis: 220px;
    }

    .timeline-item::before {
        top: -33px;
    }

    .stats-row {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
    }

    .stat-item {
        padding: 18px 12px;
    }

    .stat-number {
        font-size: 1.625rem;
    }

    .about-content p {
        text-align: left;
    }

    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 40px;
        height: 40px;
    }

    .footer-links {
        gap: 6px;
    }

    .footer-links a {
        padding: 4px 10px;
        font-size: 0.75rem;
    }
}

/* ===== 入场动效 =====
   .reveal 由 JS 动态添加，未启用 JavaScript 时不影响任何内容显示。
   动画结束后 JS 会移除标记，避免干扰卡片自身的悬停位移。 */
.reveal {
    opacity: 0;
    transform: translateY(18px);
    transition: opacity 0.6s cubic-bezier(0.22, 0.61, 0.36, 1) var(--reveal-delay, 0s),
                transform 0.6s cubic-bezier(0.22, 0.61, 0.36, 1) var(--reveal-delay, 0s);
}

.reveal.is-visible {
    opacity: 1;
    transform: none;
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    .reveal,
    .reveal.is-visible {
        opacity: 1;
        transform: none;
        transition: none;
    }
}