/* ==========================================================================
   储物袋官网 公共样式
   设计关键词：安静 / 现代 / 克制 / 高级 / 可信 / 长期陪伴
   ========================================================================== */

:root {
    --bg: #fbfbf9;
    --bg-soft: #f4f4f0;
    --ink: #1b1d22;
    --ink-soft: #3c3f46;
    --muted: #767a83;
    --line: #e7e7e1;
    --accent: #2f6bff;
    --accent-soft: rgba(47, 107, 255, 0.08);
    --dark: #0f1116;
    --dark-2: #161922;
    --dark-line: rgba(255, 255, 255, 0.1);
    --dark-muted: rgba(255, 255, 255, 0.55);
    --radius: 16px;
    --font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
        "Microsoft YaHei", "Noto Sans SC", "Helvetica Neue", Arial, sans-serif;
    --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--ink);
    line-height: 1.75;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
    overflow-x: hidden;
}

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

a {
    color: inherit;
    text-decoration: none;
}

.container {
    width: min(1120px, calc(100% - 48px));
    margin: 0 auto;
}

/* --------------------------------------------------------------------------
   导航栏：固定顶部 + 轻微毛玻璃
   -------------------------------------------------------------------------- */

.nav {
    position: fixed;
    inset: 0 0 auto 0;
    z-index: 100;
    backdrop-filter: saturate(180%) blur(14px);
    -webkit-backdrop-filter: saturate(180%) blur(14px);
    background: rgba(251, 251, 249, 0.72);
    border-bottom: 1px solid transparent;
    transition: border-color 0.4s var(--ease), background 0.4s var(--ease);
}

.nav.is-scrolled {
    border-bottom-color: var(--line);
    background: rgba(251, 251, 249, 0.86);
}

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

.brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 17px;
    font-weight: 600;
    letter-spacing: 0.02em;
}

.brand-icon {
    width: 26px;
    height: 26px;
    border-radius: 7px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 34px;
    font-size: 14px;
    color: var(--ink-soft);
}

.nav-links a {
    position: relative;
    padding: 4px 0;
    transition: color 0.3s var(--ease);
}

.nav-links a:hover {
    color: var(--ink);
}

/* 语言切换 */

.lang {
    position: relative;
}

.lang-toggle {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 14px;
    color: var(--ink-soft);
    background: none;
    border: none;
    cursor: pointer;
    font-family: inherit;
    padding: 4px 0;
}

.lang-toggle svg {
    transition: transform 0.3s var(--ease);
}

.lang.is-open .lang-toggle svg {
    transform: rotate(180deg);
}

.lang-menu {
    position: absolute;
    top: calc(100% + 10px);
    right: 0;
    min-width: 150px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 12px;
    box-shadow: 0 12px 32px rgba(27, 29, 34, 0.1);
    padding: 6px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-6px);
    transition: all 0.28s var(--ease);
}

.lang.is-open .lang-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.lang-menu a,
.lang-menu span {
    display: block;
    padding: 8px 12px;
    border-radius: 8px;
    font-size: 13.5px;
    color: var(--ink-soft);
    white-space: nowrap;
}

.lang-menu a:hover {
    background: var(--bg-soft);
    color: var(--ink);
}

.lang-menu .is-active {
    color: var(--ink);
    font-weight: 500;
}

.lang-menu .is-disabled {
    color: #b9bcc2;
    cursor: default;
}

/* --------------------------------------------------------------------------
   通用版块
   -------------------------------------------------------------------------- */

.section {
    padding: 140px 0;
}

.section-title {
    font-size: clamp(28px, 4vw, 42px);
    font-weight: 600;
    line-height: 1.4;
    letter-spacing: 0.01em;
}

.section-lead {
    margin-top: 20px;
    font-size: 17px;
    color: var(--muted);
    max-width: 640px;
}

.emphasis {
    font-size: clamp(19px, 2.4vw, 24px);
    font-weight: 600;
    line-height: 1.9;
}

/* 滚动进入动画：平缓浮现 */

.reveal {
    opacity: 0;
    transform: translateY(28px);
    transition: opacity 0.9s var(--ease), transform 0.9s var(--ease);
}

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

.reveal[data-delay="1"] { transition-delay: 0.15s; }
.reveal[data-delay="2"] { transition-delay: 0.3s; }
.reveal[data-delay="3"] { transition-delay: 0.45s; }

/* --------------------------------------------------------------------------
   按钮
   -------------------------------------------------------------------------- */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    height: 48px;
    padding: 0 30px;
    border-radius: 999px;
    font-size: 15px;
    font-weight: 500;
    letter-spacing: 0.02em;
    transition: all 0.35s var(--ease);
    border: 1px solid transparent;
    cursor: pointer;
}

.btn-primary {
    background: var(--ink);
    color: #fff;
}

.btn-primary:hover {
    background: #000;
    transform: translateY(-1px);
}

.btn-ghost {
    border-color: var(--line);
    color: var(--ink);
    background: transparent;
}

.btn-ghost:hover {
    border-color: var(--ink);
}

.btn-light {
    background: #fff;
    color: var(--ink);
}

.btn-light:hover {
    transform: translateY(-1px);
}

/* --------------------------------------------------------------------------
   第一屏 Hero
   -------------------------------------------------------------------------- */

.hero {
    padding: 148px 0 100px;
    overflow: hidden;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1.05fr 0.95fr;
    gap: 72px;
    align-items: center;
}

.hero-title {
    font-size: clamp(34px, 4.6vw, 54px);
    font-weight: 600;
    line-height: 1.45;
    letter-spacing: 0.01em;
}

.hero-sub {
    margin-top: 28px;
    font-size: 17px;
    color: var(--muted);
    max-width: 480px;
}

.hero-emphasis {
    margin-top: 32px;
    font-size: 18px;
    font-weight: 600;
    line-height: 2;
}

.hero-actions {
    margin-top: 44px;
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.hero-platforms {
    margin-top: 18px;
    font-size: 13px;
    color: var(--muted);
    letter-spacing: 0.02em;
}

/* Hero 右侧：手机 + 文件汇聚动画 */

.hero-visual {
    position: relative;
    display: flex;
    justify-content: center;
}

.phone {
    position: relative;
    width: 270px;
    border-radius: 40px;
    padding: 10px;
    background: #20222a;
    box-shadow: 0 30px 70px rgba(27, 29, 34, 0.22), 0 4px 14px rgba(27, 29, 34, 0.12);
}

.phone::before {
    content: "";
    position: absolute;
    top: 22px;
    left: 50%;
    transform: translateX(-50%);
    width: 78px;
    height: 20px;
    border-radius: 999px;
    background: #20222a;
    z-index: 2;
}

.phone img {
    width: 100%;
    height: auto;
    border-radius: 31px;
}

/* 来源文件图标缓慢飞向手机 */

.fly-icon {
    position: absolute;
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 9px 14px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 12px;
    font-size: 12.5px;
    color: var(--ink-soft);
    box-shadow: 0 6px 18px rgba(27, 29, 34, 0.08);
    white-space: nowrap;
    animation: flyIn 12s var(--ease) infinite;
    opacity: 0;
}

.fly-icon i {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    flex: none;
}

.fly-icon:nth-of-type(1) { top: 6%;  left: -4%;  animation-delay: 0s; }
.fly-icon:nth-of-type(2) { top: 2%;  right: -2%; animation-delay: 0.6s; }
.fly-icon:nth-of-type(3) { top: 38%; left: -12%; animation-delay: 1.2s; }
.fly-icon:nth-of-type(4) { top: 70%; left: -6%;  animation-delay: 1.8s; }
.fly-icon:nth-of-type(5) { top: 82%; right: -4%; animation-delay: 2.4s; }
.fly-icon:nth-of-type(6) { top: 44%; right: -10%; animation-delay: 3s; }

@keyframes flyIn {
    0% {
        opacity: 0;
        transform: translate(0, 0) scale(1);
    }
    8% {
        opacity: 1;
    }
    38% {
        opacity: 1;
        transform: translate(var(--fx, 120px), var(--fy, 120px)) scale(0.72);
    }
    46%, 100% {
        opacity: 0;
        transform: translate(var(--fx, 120px), var(--fy, 120px)) scale(0.5);
    }
}

/* --------------------------------------------------------------------------
   第二屏：为什么需要储物袋
   -------------------------------------------------------------------------- */

.why {
    background: var(--bg-soft);
}

.why-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.why-body {
    margin-top: 28px;
    color: var(--ink-soft);
    font-size: 16.5px;
}

.why-emphasis {
    margin-top: 40px;
}

.why-illustration {
    display: flex;
    justify-content: center;
}

.why-illustration svg {
    width: min(420px, 100%);
    height: auto;
}

.float-doc {
    animation: floatY 7s ease-in-out infinite;
}

.float-doc:nth-of-type(2n) { animation-delay: -2s; }
.float-doc:nth-of-type(3n) { animation-delay: -4s; }

@keyframes floatY {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

/* --------------------------------------------------------------------------
   第三屏：汇集 / 整理 / 找到 三列卡片
   -------------------------------------------------------------------------- */

.values-grid {
    margin-top: 72px;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.value-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 48px 36px;
    transition: transform 0.5s var(--ease), box-shadow 0.5s var(--ease);
}

.value-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 18px 44px rgba(27, 29, 34, 0.07);
}

.value-card h3 {
    font-size: 24px;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 12px;
}

.value-card h3::before {
    content: "";
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--accent);
    flex: none;
}

.value-card .value-lead {
    margin-top: 18px;
    font-size: 17px;
    font-weight: 500;
    line-height: 1.8;
}

.value-card .value-body {
    margin-top: 14px;
    color: var(--muted);
    font-size: 15px;
}

/* --------------------------------------------------------------------------
   第四屏：重新定义文件管理
   -------------------------------------------------------------------------- */

.redefine {
    background: var(--bg-soft);
}

.redefine-head {
    text-align: center;
    max-width: 720px;
    margin: 0 auto;
}

.redefine-grid {
    margin-top: 80px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

/* 左侧：传统文件夹结构，不断展开 */

.folder-tree {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 36px 32px;
    font-size: 15px;
    color: var(--ink-soft);
}

.folder-node {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 7px 0;
    opacity: 0;
    transform: translateX(-8px);
    transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}

.folder-tree.is-visible .folder-node {
    opacity: 1;
    transform: none;
}

.folder-tree.is-visible .folder-node:nth-child(1) { transition-delay: 0.1s; }
.folder-tree.is-visible .folder-node:nth-child(2) { transition-delay: 0.5s; }
.folder-tree.is-visible .folder-node:nth-child(3) { transition-delay: 0.9s; }
.folder-tree.is-visible .folder-node:nth-child(4) { transition-delay: 1.3s; }
.folder-tree.is-visible .folder-node:nth-child(5) { transition-delay: 1.7s; }
.folder-tree.is-visible .folder-node:nth-child(6) { transition-delay: 2.1s; }

.folder-node svg {
    flex: none;
    color: #b7bac2;
}

.folder-node.is-chaos {
    color: #b0453c;
}

.folder-node.depth-1 { padding-left: 26px; }
.folder-node.depth-2 { padding-left: 52px; }
.folder-node.depth-3 { padding-left: 78px; }
.folder-node.depth-4 { padding-left: 104px; }
.folder-node.depth-5 { padding-left: 130px; }

.redefine-caption {
    margin-top: 18px;
    font-size: 13.5px;
    color: var(--muted);
    text-align: center;
}

/* 右侧：真实产品截图（六维组织） */

.redefine-shot {
    display: flex;
    justify-content: center;
}

.redefine-foot {
    margin-top: 80px;
    text-align: center;
}

/* --------------------------------------------------------------------------
   第五屏：搜索（深色）
   -------------------------------------------------------------------------- */

.search-section {
    background: var(--dark);
    color: #fff;
}

.search-section .section-title {
    text-align: center;
}

.search-stage {
    margin: 72px auto 0;
    max-width: 720px;
}

.search-box {
    display: flex;
    align-items: center;
    gap: 14px;
    background: var(--dark-2);
    border: 1px solid var(--dark-line);
    border-radius: 18px;
    padding: 22px 26px;
    font-size: clamp(18px, 2.4vw, 24px);
}

.search-box svg {
    flex: none;
    color: var(--dark-muted);
}

.search-text {
    min-height: 1.5em;
    font-weight: 500;
    letter-spacing: 0.02em;
}

.search-caret {
    display: inline-block;
    width: 2px;
    height: 1.1em;
    margin-left: 3px;
    background: var(--accent);
    vertical-align: text-bottom;
    animation: caretBlink 1.1s steps(2) infinite;
}

@keyframes caretBlink {
    50% { opacity: 0; }
}

.search-result {
    margin-top: 18px;
    background: var(--dark-2);
    border: 1px solid var(--dark-line);
    border-radius: 14px;
    padding: 16px 22px;
    display: flex;
    align-items: center;
    gap: 14px;
    font-size: 15px;
    color: rgba(255, 255, 255, 0.85);
    opacity: 0;
    transform: translateY(8px);
    transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}

.search-result.is-shown {
    opacity: 1;
    transform: none;
}

.search-result .file-tag {
    flex: none;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.06em;
    padding: 3px 8px;
    border-radius: 6px;
    background: var(--accent-soft);
    color: #7ea2ff;
    border: 1px solid rgba(47, 107, 255, 0.3);
}

.search-result .file-meta {
    margin-left: auto;
    font-size: 12.5px;
    color: var(--dark-muted);
    white-space: nowrap;
}

.search-foot {
    margin-top: 72px;
    text-align: center;
    color: rgba(255, 255, 255, 0.9);
}

/* --------------------------------------------------------------------------
   第六屏：属于你的文件（隐私）
   -------------------------------------------------------------------------- */

.privacy-grid {
    display: grid;
    grid-template-columns: 1.05fr 0.95fr;
    gap: 80px;
    align-items: center;
}

.privacy-body {
    margin-top: 28px;
    color: var(--ink-soft);
    font-size: 16.5px;
}

.privacy-list {
    margin-top: 26px;
    list-style: none;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px 24px;
    font-size: 15px;
    color: var(--ink-soft);
}

.privacy-list li {
    display: flex;
    align-items: center;
    gap: 10px;
}

.privacy-list li::before {
    content: "";
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--accent);
    flex: none;
}

.privacy-emphasis {
    margin-top: 40px;
}

.privacy-shot {
    display: flex;
    justify-content: center;
}

/* --------------------------------------------------------------------------
   第七屏：使用体验 九宫格
   -------------------------------------------------------------------------- */

.experience {
    background: var(--bg-soft);
}

.exp-grid {
    margin-top: 72px;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.exp-item {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 36px 30px;
    transition: transform 0.5s var(--ease), box-shadow 0.5s var(--ease);
}

.exp-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 14px 36px rgba(27, 29, 34, 0.06);
}

.exp-item svg {
    color: var(--ink);
}

.exp-item h3 {
    margin-top: 18px;
    font-size: 17px;
    font-weight: 600;
}

.exp-item p {
    margin-top: 6px;
    font-size: 14px;
    color: var(--muted);
}

/* --------------------------------------------------------------------------
   第八屏：适合每一种使用方式
   -------------------------------------------------------------------------- */

.scenes-grid {
    margin-top: 72px;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.scene-card {
    border: 1px solid var(--line);
    border-radius: var(--radius);
    overflow: hidden;
    background: #fff;
    transition: transform 0.5s var(--ease), box-shadow 0.5s var(--ease);
}

.scene-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 14px 36px rgba(27, 29, 34, 0.06);
}

.scene-visual {
    aspect-ratio: 4 / 3;
    display: grid;
    place-items: center;
}

.scene-visual svg {
    width: 56px;
    height: 56px;
}

.scene-1 .scene-visual { background: #eef2fb; color: #3c64b8; }
.scene-2 .scene-visual { background: #f0f4ef; color: #4a7351; }
.scene-3 .scene-visual { background: #f7f1ea; color: #96683c; }
.scene-4 .scene-visual { background: #f4eff4; color: #7a5578; }

.scene-body {
    padding: 24px 26px 30px;
}

.scene-body h3 {
    font-size: 18px;
    font-weight: 600;
}

.scene-body p {
    margin-top: 8px;
    font-size: 14px;
    color: var(--muted);
    line-height: 1.9;
}

/* --------------------------------------------------------------------------
   第九屏：全平台支持
   -------------------------------------------------------------------------- */

.platforms {
    background: var(--bg-soft);
    text-align: center;
}

.platforms .section-lead {
    margin-left: auto;
    margin-right: auto;
}

/* 三级平台结构：移动（全功能）/ 桌面（互传）/ 大屏（消费） */

.tier-list {
    margin-top: 80px;
    display: flex;
    flex-direction: column;
    gap: 28px;
    text-align: left;
}

.tier {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 20px;
    padding: 48px 56px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 56px;
    align-items: center;
}

.tier-reverse .tier-info { order: 2; }
.tier-reverse .tier-visual { order: 1; }

.tier-info h3 {
    font-size: 24px;
    font-weight: 600;
}

.tier-tag {
    margin-top: 8px;
    font-size: 14px;
    font-weight: 500;
    color: var(--accent);
    letter-spacing: 0.02em;
}

.tier-desc {
    margin-top: 14px;
    font-size: 15px;
    color: var(--muted);
}

.tier-platforms {
    margin-top: 26px;
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.tier-platforms .chip-logo {
    width: 15px;
    height: 15px;
    flex: none;
}

.tier-platforms a,
.tier-platforms .tier-soon {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    border: 1px solid var(--line);
    border-radius: 999px;
    font-size: 14.5px;
    font-weight: 500;
    color: var(--ink);
    background: #fff;
    transition: border-color 0.3s var(--ease), transform 0.3s var(--ease);
}

.tier-platforms a:hover {
    border-color: var(--ink);
    transform: translateY(-1px);
}

.tier-platforms .tier-soon {
    color: var(--muted);
    cursor: default;
}

.badge {
    font-size: 11px;
    font-weight: 500;
    padding: 2px 8px;
    border-radius: 999px;
    letter-spacing: 0.02em;
}

.badge-ok {
    background: rgba(46, 160, 90, 0.1);
    color: #2e8f57;
}

.badge-plan {
    background: var(--bg-soft);
    color: var(--muted);
    border: 1px solid var(--line);
}

.tier-note {
    margin-top: 16px;
    font-size: 13px;
    color: var(--muted);
}

.tier-note a {
    color: var(--accent);
    border-bottom: 1px solid transparent;
    transition: border-color 0.3s var(--ease);
}

.tier-note a:hover {
    border-bottom-color: var(--accent);
}

.tier-visual {
    display: flex;
    justify-content: center;
}

.phone-sm {
    width: 200px;
}

/* 桌面窗口 / 电视外框 */

.shot-window {
    width: 100%;
    max-width: 460px;
    border-radius: 14px;
    overflow: hidden;
    border: 1px solid var(--line);
    box-shadow: 0 24px 56px rgba(27, 29, 34, 0.14);
}

.shot-window img {
    width: 100%;
    height: auto;
}

.shot-tv {
    width: 100%;
    max-width: 480px;
    border-radius: 14px;
    overflow: hidden;
    background: #000;
    border: 6px solid #20222a;
    box-shadow: 0 24px 56px rgba(27, 29, 34, 0.18);
}

.shot-tv img {
    width: 100%;
    height: auto;
}

.platforms-foot {
    margin-top: 72px;
    font-size: 17px;
    color: var(--ink-soft);
}

/* 页脚备案 */

.footer-bottom a {
    transition: color 0.3s var(--ease);
}

.footer-bottom a:hover {
    color: rgba(255, 255, 255, 0.7);
}

.beian {
    display: inline-flex;
    align-items: center;
    gap: 18px;
    flex-wrap: wrap;
}

.beian a {
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.beian-icon {
    width: 14px;
    height: 14px;
}

/* --------------------------------------------------------------------------
   技术支持（白底）
   -------------------------------------------------------------------------- */

.support-grid {
    margin-top: 64px;
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 360px));
    justify-content: center;
    gap: 24px;
}

.support-item {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 44px 32px;
    text-align: center;
    transition: transform 0.5s var(--ease), box-shadow 0.5s var(--ease), border-color 0.3s var(--ease);
}

.support-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 14px 36px rgba(27, 29, 34, 0.06);
    border-color: #d8d8d2;
}

.support-icon {
    font-size: 28px;
    line-height: 1;
}

.support-item h3 {
    margin-top: 16px;
    font-size: 17px;
    font-weight: 600;
}

.support-item p {
    margin-top: 6px;
    font-size: 14.5px;
    color: var(--accent);
}

/* 锚点定位时为固定导航预留空间 */

section[id] {
    scroll-margin-top: 72px;
}

/* --------------------------------------------------------------------------
   动态页
   -------------------------------------------------------------------------- */

.news-page {
    padding: 148px 0 120px;
}

.news-page-header {
    text-align: center;
    margin-bottom: 56px;
}

.news-page-header h1 {
    font-size: clamp(30px, 4vw, 40px);
    font-weight: 600;
}

.news-page-header p {
    margin-top: 10px;
    color: var(--muted);
}

.news-list {
    max-width: 760px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.news-item {
    border: 1px solid var(--line);
    border-radius: var(--radius);
    overflow: hidden;
    background: #fff;
}

.news-item__question {
    width: 100%;
    text-align: left;
    background: #fff;
    border: none;
    padding: 26px 28px;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    gap: 6px;
    font-family: inherit;
}

.news-item__date {
    font-size: 13px;
    color: var(--muted);
}

.news-item__title {
    font-size: 18px;
    font-weight: 600;
    color: var(--ink);
}

.news-item__range {
    font-size: 14px;
    font-weight: 500;
    color: var(--accent);
}

.news-item__summary {
    margin-top: 2px;
    font-size: 14px;
    line-height: 1.6;
    color: var(--muted);
}

.news-item__toggle {
    margin-top: 8px;
    font-size: 13px;
    font-weight: 500;
    color: var(--accent);
}

.news-item__toggle::before {
    content: "▼ ";
}

.news-item.is-open .news-item__toggle::before {
    content: "▲ ";
}

.news-item__body {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s var(--ease);
    background: var(--bg-soft);
}

.news-item__body-inner {
    padding: 12px 28px 30px;
}

.news-body__title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 12px;
}

.news-body__heading {
    margin: 22px 0 8px;
    font-size: 16px;
    font-weight: 600;
    color: var(--ink);
}

.news-body__step {
    margin: 16px 0 4px;
    font-size: 15px;
    font-weight: 600;
    color: var(--ink);
}

.news-body__p {
    margin-top: 6px;
    font-size: 14px;
    line-height: 1.75;
    color: var(--ink-soft);
}

.news-body__p a {
    color: var(--accent);
    word-break: break-all;
}

.news-body__list {
    margin-top: 6px;
    padding-left: 20px;
    font-size: 14px;
    line-height: 1.8;
    color: var(--ink-soft);
}

.news-body__list li {
    margin-bottom: 4px;
}

@media (max-width: 600px) {
    .news-page { padding: 116px 0 80px; }
    .news-item__question { padding: 22px 20px; }
    .news-item__body-inner { padding: 8px 20px 26px; }
}

/* --------------------------------------------------------------------------
   相关产品页
   -------------------------------------------------------------------------- */

.product-hero {
    padding: 160px 0 72px;
}

.product-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 20px;
    padding: 48px 56px;
    display: grid;
    grid-template-columns: 96px 1fr;
    gap: 36px;
    align-items: start;
}

.product-card-logo {
    width: 96px;
    height: 96px;
    border-radius: 22px;
    box-shadow: 0 12px 28px rgba(27, 29, 34, 0.14);
}

.product-card h3 {
    font-size: 24px;
    font-weight: 600;
}

.product-card .product-tagline {
    margin-top: 6px;
    font-size: 16px;
    font-weight: 500;
    color: var(--ink-soft);
}

.product-card .product-desc {
    margin-top: 14px;
    font-size: 15px;
    color: var(--muted);
}

.product-tags {
    margin-top: 18px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    list-style: none;
}

.product-tags li {
    font-size: 13px;
    color: var(--ink-soft);
    border: 1px solid var(--line);
    border-radius: 999px;
    padding: 5px 14px;
}

.product-actions {
    margin-top: 26px;
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
}

/* 卡片内下载区域 */

.product-dl {
    margin-top: 32px;
    padding-top: 26px;
    border-top: 1px solid var(--line);
}

.product-dl h4 {
    font-size: 16px;
    font-weight: 600;
}

.product-dl-note {
    margin-top: 8px;
    font-size: 13.5px;
    color: var(--muted);
}

.dl-platform {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    white-space: nowrap;
}

.dl-platform svg {
    width: 15px;
    height: 15px;
    flex: none;
}

.dl-table {
    margin-top: 18px;
    width: 100%;
    border-collapse: collapse;
    font-size: 13.5px;
}

.dl-table th,
.dl-table td {
    text-align: left;
    padding: 8px 0;
    border-bottom: 1px solid var(--line);
    color: var(--ink-soft);
}

.dl-table th {
    font-weight: 500;
    color: var(--muted);
    font-size: 12.5px;
}

.dl-table tr:last-child td {
    border-bottom: none;
}

.dl-table a {
    color: var(--accent);
    word-break: break-all;
}

/* 页面结束 */

.product-end {
    text-align: center;
    padding: 40px 0 140px;
}

.product-end .section-lead {
    margin-left: auto;
    margin-right: auto;
}

@media (max-width: 960px) {
    .product-card { grid-template-columns: 72px 1fr; padding: 36px 28px; gap: 24px; }
    .product-card-logo { width: 72px; height: 72px; border-radius: 17px; }
}

@media (max-width: 600px) {
    .product-hero { padding: 124px 0 56px; }
    .product-card { grid-template-columns: 1fr; }
    .product-end { padding: 24px 0 96px; }
}

/* --------------------------------------------------------------------------
   第十屏：品牌理念（纯黑）
   -------------------------------------------------------------------------- */

.philosophy {
    background: #000;
    color: #fff;
    text-align: center;
    padding: 180px 0;
}

.philosophy .section-title {
    max-width: 720px;
    margin: 0 auto;
}

.philosophy-body {
    margin: 36px auto 0;
    max-width: 560px;
    color: rgba(255, 255, 255, 0.62);
    font-size: 16.5px;
}

.philosophy-end {
    margin-top: 56px;
    font-size: clamp(20px, 2.6vw, 26px);
    font-weight: 600;
    letter-spacing: 0.04em;
}

.philosophy .btn {
    margin-top: 48px;
}

/* --------------------------------------------------------------------------
   页脚
   -------------------------------------------------------------------------- */

.footer {
    background: #000;
    color: rgba(255, 255, 255, 0.55);
    border-top: 1px solid var(--dark-line);
    padding: 64px 0 48px;
    font-size: 13.5px;
}

.footer-top {
    display: flex;
    justify-content: space-between;
    gap: 48px;
    flex-wrap: wrap;
}

.footer-brand .brand {
    color: #fff;
}

.footer-slogan {
    margin-top: 14px;
    color: rgba(255, 255, 255, 0.45);
}

.footer-links {
    display: flex;
    gap: 72px;
    flex-wrap: wrap;
}

.footer-col h4 {
    font-size: 13px;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: 14px;
    letter-spacing: 0.04em;
}

.footer-col a,
.footer-col span {
    display: block;
    padding: 4px 0;
    transition: color 0.3s var(--ease);
}

.footer-col a:hover {
    color: #fff;
}

.footer-bottom {
    margin-top: 56px;
    padding-top: 24px;
    border-top: 1px solid var(--dark-line);
    display: flex;
    justify-content: space-between;
    gap: 16px;
    flex-wrap: wrap;
    color: rgba(255, 255, 255, 0.35);
    font-size: 12.5px;
}

/* --------------------------------------------------------------------------
   英文占位首页
   -------------------------------------------------------------------------- */

.placeholder {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 120px 24px;
    gap: 18px;
}

.placeholder h1 {
    font-size: clamp(30px, 4vw, 44px);
    font-weight: 600;
}

.placeholder p {
    color: var(--muted);
    max-width: 460px;
}

.placeholder .lang-entry {
    margin-top: 24px;
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
    justify-content: center;
}

/* --------------------------------------------------------------------------
   响应式
   -------------------------------------------------------------------------- */

@media (max-width: 960px) {
    .section { padding: 96px 0; }

    .hero { padding: 132px 0 88px; }

    .hero-grid,
    .why-grid,
    .privacy-grid,
    .redefine-grid {
        grid-template-columns: 1fr;
        gap: 56px;
    }

    .hero-visual { order: -1; }

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

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

    .tier {
        grid-template-columns: 1fr;
        gap: 40px;
        padding: 40px 32px;
    }

    .tier-reverse .tier-info { order: 1; }
    .tier-reverse .tier-visual { order: 2; }

    .fly-icon { display: none; }
}

@media (max-width: 600px) {
    .container { width: calc(100% - 40px); }

    .section { padding: 80px 0; }

    .hero { padding: 116px 0 72px; }

    /* 导航：小屏仅保留下载与语言入口 */
    .nav-inner { height: 56px; }
    .brand { white-space: nowrap; font-size: 15px; }
    .brand-icon { width: 22px; height: 22px; }
    .nav-links { gap: 10px; font-size: 12px; white-space: nowrap; }
    .nav-links a[href$="#product"],
    .nav-links a[href$="#philosophy"],
    .nav-links a[href$="#support"],
    .nav-links a[href*="news.html"] { display: none; }

    /* 拉丁语系标签较长，小屏再隐藏产品页入口 */
    html[lang="en"] .nav-links a[href*="product.html"],
    html[lang="es"] .nav-links a[href*="product.html"],
    html[lang="de"] .nav-links a[href*="product.html"],
    html[lang="fr"] .nav-links a[href*="product.html"] { display: none; }

    .hero-title { font-size: 30px; }
    .hero-sub { font-size: 15.5px; }
    .hero-emphasis { font-size: 16.5px; }
    .hero-actions .btn { height: 46px; padding: 0 24px; font-size: 14.5px; }

    .section-title { font-size: 27px; }
    .emphasis { font-size: 19px; }

    .values-grid,
    .exp-grid,
    .scenes-grid,
    .support-grid { grid-template-columns: 1fr; }

    .value-card { padding: 36px 28px; }

    .support-item { padding: 36px 24px; }

    /* 文件夹树：收窄缩进避免溢出 */
    .folder-tree { padding: 26px 20px; font-size: 14px; }
    .folder-node.depth-1 { padding-left: 16px; }
    .folder-node.depth-2 { padding-left: 32px; }
    .folder-node.depth-3 { padding-left: 48px; }
    .folder-node.depth-4 { padding-left: 64px; }
    .folder-node.depth-5 { padding-left: 80px; }

    /* 搜索演示框 */
    .search-box { padding: 16px 18px; border-radius: 14px; }
    .search-result { padding: 13px 16px; font-size: 13.5px; }
    .search-result .file-meta { display: none; }

    .privacy-list { grid-template-columns: 1fr; }

    .tier { padding: 32px 22px; gap: 32px; }
    .tier-info h3 { font-size: 21px; }
    .tier-platforms a,
    .tier-platforms .tier-soon { padding: 9px 15px; font-size: 13.5px; }

    .phone { width: min(240px, 72vw); }
    .phone-sm { width: min(200px, 60vw); }

    .philosophy { padding: 120px 0; }

    .footer-top { gap: 36px; }
    .footer-links { gap: 48px; }
    .footer-bottom { flex-direction: column; gap: 10px; }
}

/* 尊重减少动态偏好 */

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    html { scroll-behavior: auto; }
    .reveal { opacity: 1; transform: none; }
}