/* ==========================================================================
   DocuSpeed 2026 — deep-space design system
   ========================================================================== */

@font-face {
    font-family: 'Open Sans Condensed';
    src: url('/fonts/OpenSans-CondBold.ttf') format('truetype');
    font-weight: 700;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Open Sans Condensed';
    src: url('/fonts/OpenSans-CondLight.ttf') format('truetype');
    font-weight: 300;
    font-style: normal;
    font-display: swap;
}

:root {
    --canvas: #000000;
    --canvas-soft: #050505;
    --deep-navy: #1B3C53;
    --steel-blue: #456882;
    --warm-gray: #D2C1B6;
    --soft-cream: #F9F3EF;
    --accent-cosmic: #85C7E8;
    --accent-solar: #F5C96B;
    --text-primary: var(--soft-cream);
    --text-secondary: rgba(249, 243, 239, 0.72);
    --text-muted: rgba(249, 243, 239, 0.55);
    --line: rgba(210, 193, 182, 0.16);
    --line-strong: rgba(69, 104, 130, 0.55);
    --panel: rgba(27, 60, 83, 0.26);
    --panel-strong: rgba(27, 60, 83, 0.46);
    --shadow: 0 24px 80px rgba(0, 0, 0, 0.45);
    --radius-sm: 8px;
    --radius-md: 14px;
    --radius-lg: 20px;
    --container: 1200px;
    /* Hero 背景图左缘相对内容容器左缘的距离：宽屏 700px，窄桌面按 55vw 缩放 */
    --hero-media-offset: clamp(360px, 55vw, 700px);
    --nav-height: 72px;
    --font-display: 'Open Sans Condensed', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    --font-body: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Segoe UI', sans-serif;
    --product-accent: var(--accent-cosmic);

    /* 兼容旧博客正文中的内联样式变量 */
    --primary-color: var(--deep-navy);
    --secondary-color: var(--steel-blue);
    --accent-color: var(--warm-gray);
    --background-color: var(--canvas-soft);
    color-scheme: dark;
}

/* 中文页标题统一系统黑体，避免拉丁字符落到窄体造成中英文宽窄不一；英文页保持 Open Sans Condensed。 */
html:lang(zh) {
    --font-display: var(--font-body);
}

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

html {
    scroll-behavior: smooth;
    scrollbar-gutter: stable;
}

body {
    min-height: 100vh;
    background: var(--canvas);
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.65;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

.i18n-pending body {
    visibility: hidden;
}

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

img {
    height: auto;
}

a {
    color: inherit;
}

button {
    font: inherit;
}

::selection {
    background: var(--accent-cosmic);
    color: var(--canvas);
}

:focus-visible {
    outline: 2px solid var(--accent-cosmic);
    outline-offset: 4px;
}

.skip-link {
    position: fixed;
    top: -100px;
    left: 24px;
    z-index: 2000;
    padding: 10px 16px;
    border-radius: var(--radius-sm);
    background: var(--soft-cream);
    color: var(--deep-navy);
    font-weight: 700;
    text-decoration: none;
}

.skip-link:focus {
    top: 16px;
}

.container {
    width: min(100% - 48px, var(--container));
    margin-inline: auto;
}

[id] {
    scroll-margin-top: calc(var(--nav-height) + 24px);
}

.section {
    padding: 112px 0;
}

.section-compact {
    padding: 72px 0;
}

.section-head {
    max-width: 780px;
    margin-bottom: 56px;
}

.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
    color: var(--product-accent);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.14em;
    line-height: 1.4;
    text-transform: uppercase;
}

html:lang(zh) .eyebrow {
    font-size: 13px;
    letter-spacing: 0.04em;
}

.eyebrow::before {
    content: '';
    width: 22px;
    height: 1px;
    background: currentColor;
    opacity: 0.8;
}

.display,
.section-title,
.product-title,
.card-title {
    font-family: var(--font-display);
    font-weight: 700;
    letter-spacing: -0.01em;
    line-height: 0.98;
    text-wrap: balance;
}

.display {
    font-size: clamp(48px, 7.2vw, 96px);
}

.section-title {
    font-size: clamp(30px, 3.8vw, 48px);
}

/* 以标点分句、且每句都能放进一行的中文标题：只在标点处断行，避免把词拆到两行。 */
html:lang(zh) .wrap-phrase {
    word-break: keep-all;
    overflow-wrap: anywhere;
}

/* 中文字面更饱满，大标题需要更松的行高，字距归零。 */
html:lang(zh) .display,
html:lang(zh) .section-title,
html:lang(zh) .product-title,
html:lang(zh) .card-title {
    letter-spacing: 0;
    line-height: 1.2;
}

.section-desc,
.lead {
    color: var(--text-secondary);
    font-size: clamp(17px, 1.4vw, 20px);
    line-height: 1.72;
}

.section-desc {
    margin-top: 20px;
    max-width: 680px;
    text-wrap: pretty;
}

.section-head-wide {
    max-width: none;
}

.section-head-wide .section-desc {
    max-width: 960px;
}

/* 描述与下方整行网格同宽，例如宇宙之境的精选星系。 */
.section-head-full {
    max-width: none;
}

.section-head-full .section-desc {
    max-width: none;
}

.text-accent {
    color: var(--product-accent);
}

.muted {
    color: var(--text-muted);
}

.small {
    font-size: 13px;
}

.button-row {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 14px;
    margin-top: 32px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    min-height: 46px;
    padding: 0 20px;
    border: 1px solid transparent;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 600;
    line-height: 1;
    text-decoration: none;
    transition: transform 0.2s ease, background 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

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

.btn-primary {
    background: var(--soft-cream);
    color: var(--deep-navy);
}

.btn-primary:hover {
    background: #ffffff;
}

.btn-ghost {
    border-color: var(--line-strong);
    color: var(--text-primary);
    background: rgba(0, 0, 0, 0.2);
}

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

.btn-quiet {
    padding-inline: 4px;
    color: var(--text-secondary);
}

.btn-quiet:hover {
    color: var(--text-primary);
}

.btn-arrow {
    font-size: 16px;
    line-height: 1;
}

.reveal.is-visible {
    animation: fade-up 0.7s cubic-bezier(0.2, 0.7, 0.2, 1) both;
}

@keyframes fade-up {
    from {
        opacity: 0.35;
        transform: translateY(18px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ==========================================================================
   Navigation
   ========================================================================== */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    transition: background 0.25s ease, border-color 0.25s ease, backdrop-filter 0.25s ease;
    border-bottom: 1px solid transparent;
    background: linear-gradient(180deg, rgba(0, 0, 0, 0.74) 0%, rgba(0, 0, 0, 0.34) 58%, transparent 100%);
}

.navbar.scrolled {
    background: rgba(0, 0, 0, 0.9);
    border-bottom-color: var(--line);
    backdrop-filter: blur(16px);
}

.navbar-inner {
    display: flex;
    align-items: center;
    gap: 28px;
    width: min(100% - 48px, var(--container));
    height: var(--nav-height);
    margin-inline: auto;
}

.brand {
    display: inline-flex;
    align-items: center;
    flex-shrink: 0;
    color: var(--text-primary);
    text-decoration: none;
}

.brand-logo {
    display: block;
    width: 176px;
    height: auto;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 26px;
    margin-left: auto;
    list-style: none;
}

.nav-menu a {
    position: relative;
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
    text-decoration: none;
    white-space: nowrap;
    transition: color 0.2s ease;
}

.nav-menu a:hover,
.nav-menu a.is-active {
    color: var(--text-primary);
}

.nav-menu a.is-active::after {
    content: '';
    position: absolute;
    left: 0;
    right: 0;
    bottom: -8px;
    height: 1px;
    background: var(--product-accent);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
    border: 0;
    background: transparent;
    cursor: pointer;
}

.nav-toggle span {
    display: block;
    width: 22px;
    height: 1.5px;
    background: var(--text-primary);
    transition: transform 0.2s ease, opacity 0.2s ease;
}

.nav-toggle.is-open span:nth-child(1) {
    transform: translateY(6.5px) rotate(45deg);
}

.nav-toggle.is-open span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.is-open span:nth-child(3) {
    transform: translateY(-6.5px) rotate(-45deg);
}

.language-switch {
    position: relative;
    flex-shrink: 0;
    margin-left: 4px;
}

.language-dropdown {
    position: relative;
}

.language-current {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    min-height: 34px;
    padding: 0 12px;
    border: 1px solid var(--line-strong);
    border-radius: 999px;
    background: rgba(0, 0, 0, 0.22);
    color: var(--text-primary);
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
}

.language-current:hover {
    border-color: var(--product-accent);
}

.lang-arrow {
    font-size: 10px;
    transition: transform 0.2s ease;
}

.language-dropdown.open .lang-arrow {
    transform: rotate(180deg);
}

.language-options {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    z-index: 1001;
    min-width: 132px;
    padding: 6px;
    border: 1px solid var(--line);
    border-radius: 10px;
    background: rgba(5, 5, 5, 0.98);
    box-shadow: var(--shadow);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-4px);
    transition: opacity 0.18s ease, visibility 0.18s ease, transform 0.18s ease;
}

.language-dropdown.open .language-options {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.language-option {
    display: block;
    width: 100%;
    padding: 9px 10px;
    border: 0;
    border-radius: 6px;
    background: transparent;
    color: var(--text-secondary);
    font-size: 13px;
    text-align: left;
    cursor: pointer;
}

.language-option:hover,
.language-option.active {
    background: rgba(69, 104, 130, 0.22);
    color: var(--text-primary);
}

/* ==========================================================================
   Footer
   ========================================================================== */

.site-footer {
    padding: 72px 0 24px;
    border-top: 1px solid var(--line);
    background: var(--canvas-soft);
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.6fr 1fr 1fr 1.2fr;
    gap: 40px;
    width: min(100% - 48px, var(--container));
    margin-inline: auto;
}

.footer-brand .brand {
    margin-bottom: 14px;
}

.footer-tagline {
    max-width: 280px;
    color: var(--text-secondary);
    font-size: 14px;
}

.footer-legal-name {
    margin-top: 18px;
    color: var(--text-muted);
    font-size: 12px;
}

.footer-col h2 {
    margin-bottom: 16px;
    color: var(--text-muted);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.footer-col ul {
    display: grid;
    gap: 10px;
    list-style: none;
}

.footer-col a {
    color: var(--text-secondary);
    font-size: 14px;
    text-decoration: none;
}

.footer-col a:hover {
    color: var(--product-accent);
}

.footer-store {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
    padding: 12px 14px;
    border: 1px solid var(--line);
    border-radius: 10px;
    color: var(--text-primary);
    text-decoration: none;
    transition: border-color 0.2s ease, background 0.2s ease;
}

.footer-store:hover {
    border-color: var(--line-strong);
    background: rgba(69, 104, 130, 0.12);
}

.footer-store svg {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
}

.footer-store-name {
    font-size: 13px;
    font-weight: 600;
}

.footer-store-meta {
    display: block;
    color: var(--text-muted);
    font-size: 11px;
}

.footer-bottom {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: 12px 24px;
    width: min(100% - 48px, var(--container));
    margin: 56px auto 0;
    padding-top: 20px;
    border-top: 1px solid var(--line);
    color: var(--text-muted);
    font-size: 12px;
}

.footer-bottom a {
    color: var(--text-secondary);
    text-decoration: none;
}

.footer-bottom a:hover {
    color: var(--text-primary);
}

.footer-beian {
    color: var(--text-secondary);
}

/* ==========================================================================
   Home hero
   ========================================================================== */

.home-hero {
    position: relative;
    display: flex;
    align-items: center;
    min-height: min(100svh, 860px);
    padding: calc(var(--nav-height) + 64px) 0 96px;
    overflow: hidden;
    isolation: isolate;
}

.home-hero-media,
.product-hero-media {
    position: absolute;
    top: 0;
    left: calc(max(24px, (100% - var(--container)) / 2) + var(--hero-media-offset));
    bottom: 0;
    z-index: -1;
    width: min(64%, 1080px);
    overflow: hidden;
}

.home-hero-media img,
.product-hero-media img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    /* 星系偏右放置：右侧旋臂离开视口边缘，左侧没入文字后的渐隐。 */
    object-position: 70% 55%;
    animation: hero-settle 1.8s cubic-bezier(0.2, 0.7, 0.2, 1) both;
}

/* 背景为纯黑，用渐变遮罩代替 mask-image，让星系向左、向下自然隐入画布。 */
.home-hero-media::after,
.product-hero-media::after {
    content: '';
    position: absolute;
    inset: 0;
    background:
        linear-gradient(270deg, #000 0%, rgba(0, 0, 0, 0.72) 4%, transparent 16%),
        linear-gradient(90deg, #000 0%, rgba(0, 0, 0, 0.72) 20%, rgba(0, 0, 0, 0.12) 52%, transparent 70%),
        linear-gradient(0deg, #000 0%, transparent 32%),
        linear-gradient(180deg, rgba(0, 0, 0, 0.7) 0%, transparent 22%);
}

@keyframes hero-settle {
    from {
        opacity: 0;
        transform: scale(1.04);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.home-hero-title {
    display: grid;
    margin-bottom: 24px;
    text-shadow: 0 2px 24px rgba(0, 0, 0, 0.5);
}

.home-hero-title > span {
    display: block;
}

html:lang(zh) .home-hero-title {
    font-size: clamp(40px, 5.6vw, 76px);
    line-height: 1.16;
    letter-spacing: 0.01em;
}

html:lang(en) .home-hero-title {
    font-size: clamp(46px, 6vw, 86px);
    line-height: 0.96;
    letter-spacing: -0.015em;
}

.home-hero-lead {
    max-width: 520px;
    color: rgba(249, 243, 239, 0.82);
    text-wrap: pretty;
}

.hero-apps {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
    max-width: 680px;
    margin-top: 40px;
}

.hero-app {
    display: flex;
    align-items: center;
    gap: 14px;
    min-width: 0;
    padding: 14px 18px 14px 14px;
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    background: rgba(5, 5, 5, 0.62);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    text-decoration: none;
    transition: border-color 0.2s ease, background 0.2s ease, transform 0.2s ease;
}

.hero-app:hover {
    border-color: rgba(var(--accent-rgb), 0.6);
    background: rgba(var(--accent-rgb), 0.08);
    transform: translateY(-2px);
}

.hero-app-icon {
    width: 52px;
    height: 52px;
    flex-shrink: 0;
    border-radius: 12px;
}

.hero-app-text {
    display: grid;
    gap: 2px;
    min-width: 0;
}

.hero-app-name {
    color: var(--text-primary);
    font-size: 16px;
    font-weight: 600;
    line-height: 1.35;
}

.hero-app-desc {
    color: var(--text-secondary);
    font-size: 13px;
    line-height: 1.45;
}

.hero-app-arrow {
    margin-left: auto;
    color: var(--product-accent);
    transition: transform 0.2s ease;
}

.hero-app:hover .hero-app-arrow {
    transform: translateX(3px);
}

.hero-platform {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 20px;
    color: var(--text-muted);
    font-size: 13px;
}

.hero-platform svg {
    width: 14px;
    height: 14px;
    flex-shrink: 0;
}

/* ==========================================================================
   Home product cards
   ========================================================================== */

.app-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 24px;
}

.app-card {
    position: relative;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    background:
        linear-gradient(180deg, rgba(var(--accent-rgb), 0.07) 0%, rgba(var(--accent-rgb), 0.015) 48%, transparent 100%),
        var(--canvas-soft);
    transition: border-color 0.3s ease;
}

.app-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(var(--accent-rgb), 0.85), transparent);
}

.app-card:hover {
    border-color: rgba(var(--accent-rgb), 0.35);
}

.app-card-media {
    overflow: hidden;
    border-bottom: 1px solid var(--line);
    background: #000;
}

.app-card-media img {
    width: 100%;
    aspect-ratio: 1600 / 738;
    object-fit: cover;
    transition: transform 0.6s cubic-bezier(0.2, 0.7, 0.2, 1);
}

.app-card:hover .app-card-media img {
    transform: scale(1.02);
}

.app-card-body {
    display: flex;
    flex: 1;
    flex-direction: column;
    padding: 32px 32px 36px;
}

.app-card-head {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 20px;
}

.app-card-icon {
    width: 52px;
    height: 52px;
    flex-shrink: 0;
    border-radius: 12px;
}

.app-card-title {
    font-family: var(--font-display);
    font-size: clamp(26px, 2.4vw, 34px);
    font-weight: 700;
    line-height: 1.1;
}

.app-card-tagline {
    margin-top: 4px;
    color: var(--product-accent);
    font-size: 15px;
    line-height: 1.45;
}

.app-card-desc {
    color: var(--text-secondary);
    line-height: 1.75;
}

.app-stats-title {
    margin-top: 28px;
    padding-top: 22px;
    border-top: 1px solid var(--line);
    color: var(--text-muted);
    font-size: 13px;
    line-height: 1.4;
}

.app-stats {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
    margin: 14px 0 32px;
    list-style: none;
}

.app-stats li {
    display: grid;
    align-content: start;
    gap: 8px;
}

/* 两张卡片的数字与功能名同字号：英文用与 Logo 同款的窄体（字号略小，让 Mission replay 一行放下），
   中文统一用系统黑体。 */
.stat-value {
    color: var(--text-primary);
    font-family: 'Open Sans Condensed', var(--font-body);
    font-size: clamp(22px, 1.8vw, 26px);
    font-weight: 700;
    line-height: 1.15;
}

html:lang(zh) .stat-value {
    font-family: var(--font-body);
    font-size: clamp(24px, 2.2vw, 30px);
    font-weight: 600;
}

.stat-label {
    color: var(--text-muted);
    font-size: 13px;
    line-height: 1.45;
}

/* 中文说明只在顿号处换行，不把「经纬线」拆开。 */
html:lang(zh) .stat-label {
    word-break: keep-all;
    overflow-wrap: anywhere;
}

.app-card-actions {
    margin-top: auto;
}

/* 并排时两张卡片共用行轨道：截图、标题、描述、小标题与分割线、数字、说明、按钮逐行对齐，
   不受描述长短和换行影响。 */
@supports (grid-template-rows: subgrid) {
    @media (min-width: 901px) {
        .app-grid {
            row-gap: 0;
        }

        .app-card {
            display: grid;
            grid-row: span 7;
            grid-template-rows: subgrid;
            row-gap: 0;
        }

        .app-card-body {
            display: grid;
            grid-row: span 6;
            grid-template-rows: subgrid;
            row-gap: 0;
        }

        .app-stats {
            grid-row: span 2;
            grid-template-rows: subgrid;
            row-gap: 8px;
        }

        .app-stats li {
            grid-row: span 2;
            grid-template-rows: subgrid;
        }
    }
}

.btn-store svg {
    width: 16px;
    height: 16px;
}

:root,
[data-theme="cosmic"] {
    --accent-rgb: 133, 199, 232;
}

[data-theme="cosmic"] {
    --product-accent: var(--accent-cosmic);
}

[data-theme="solar"] {
    --product-accent: var(--accent-solar);
    --accent-rgb: 245, 201, 107;
}

/* ==========================================================================
   Home scale & sources
   ========================================================================== */

.scale-section {
    background: radial-gradient(ellipse 60% 45% at 50% 42%, rgba(27, 60, 83, 0.24), transparent 72%);
}

.scale-ranges {
    display: grid;
    grid-template-columns: repeat(14, minmax(0, 1fr));
    margin-bottom: 18px;
}

.scale-range {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 14px;
    border: 1px solid rgba(var(--accent-rgb), 0.45);
    border-radius: var(--radius-sm);
    background: rgba(var(--accent-rgb), 0.1);
    color: var(--product-accent);
    font-size: 14px;
    font-weight: 600;
    line-height: 1.3;
    text-align: center;
    text-decoration: none;
    transition: background 0.2s ease, border-color 0.2s ease;
}

.scale-range:hover {
    border-color: var(--product-accent);
    background: rgba(var(--accent-rgb), 0.18);
}

/* 七个刻度等分，刻度点位于每列中心，区间条按 14 栏对齐到刻度点。 */
.scale-range-solar {
    grid-column: 2 / 4;
    margin-right: 2px;
}

.scale-range-cosmic {
    grid-column: 4 / 14;
    margin-left: 2px;
}

.scale-ticks {
    position: relative;
    display: grid;
    grid-template-columns: repeat(7, minmax(0, 1fr));
    list-style: none;
}

/* 金色段覆盖第 1→2 个刻度，占整条轴（第 1→7 个刻度）的 1/6。 */
.scale-ticks::before {
    content: '';
    position: absolute;
    top: 5px;
    left: calc(100% / 14);
    right: calc(100% / 14);
    height: 2px;
    background: linear-gradient(90deg, var(--accent-solar) 0 16.667%, var(--accent-cosmic) 16.667% 100%);
    opacity: 0.7;
}

.scale-ticks li {
    position: relative;
    display: grid;
    align-content: start;
    gap: 4px;
    padding: 30px 6px 0;
    text-align: center;
}

.scale-tick-name {
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.4;
}

.scale-tick-span {
    color: var(--text-muted);
    font-size: 13px;
    line-height: 1.4;
}

.scale-span-note {
    margin-top: 28px;
    color: var(--text-muted);
    font-size: 13px;
}

.scale-ticks li::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    width: 12px;
    height: 12px;
    margin-left: -6px;
    border: 2px solid var(--accent-cosmic);
    border-radius: 50%;
    background: #000;
}

.scale-ticks li:first-child::before {
    border-color: var(--accent-solar);
}

.scale-ticks li:nth-child(2)::before {
    border-color: var(--soft-cream);
    background: linear-gradient(90deg, var(--accent-solar) 50%, var(--accent-cosmic) 50%);
}

.sources {
    display: grid;
    grid-template-columns: minmax(0, 0.8fr) minmax(0, 2.2fr);
    gap: 48px;
    margin-top: 96px;
    padding-top: 40px;
    border-top: 1px solid var(--line);
}

.sources-title {
    font-size: 20px;
    font-weight: 600;
    line-height: 1.4;
}

.sources-more {
    margin-top: 12px;
    color: var(--text-muted);
    font-size: 13px;
}

.sources-more > span:first-child {
    display: block;
    margin-bottom: 4px;
}

.sources-more a {
    color: var(--text-secondary);
    text-decoration: underline;
    text-decoration-color: var(--line-strong);
    text-underline-offset: 3px;
}

.sources-more a:hover {
    color: var(--text-primary);
}

.sources-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 32px;
}

.source-item h4 {
    margin-bottom: 8px;
    font-size: 15px;
    font-weight: 600;
}

.source-item p {
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.7;
}

/* ==========================================================================
   Home articles
   ========================================================================== */

.text-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin-top: 28px;
    padding-bottom: 4px;
    border-bottom: 1px solid var(--line-strong);
    color: var(--text-primary);
    font-size: 15px;
    font-weight: 600;
    text-decoration: none;
    transition: color 0.2s ease, border-color 0.2s ease;
}

.text-link:hover {
    border-color: var(--product-accent);
    color: var(--product-accent);
}

.articles-section {
    border-top: 1px solid var(--line);
}

.articles-head {
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    gap: 24px;
    margin-bottom: 40px;
}

.articles-head .text-link {
    flex-shrink: 0;
    margin-top: 0;
}

.article-list {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0 40px;
}

.article-item {
    display: flex;
    flex-direction: column;
    padding: 28px 0 8px;
    border-top: 1px solid var(--line-strong);
    color: var(--text-primary);
    text-decoration: none;
}

.article-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 14px;
    color: var(--text-muted);
    font-size: 13px;
}

.article-category {
    color: var(--product-accent);
    font-weight: 600;
}

.article-title {
    margin-bottom: 12px;
    font-family: var(--font-display);
    font-size: clamp(20px, 1.8vw, 24px);
    font-weight: 700;
    line-height: 1.35;
    transition: color 0.2s ease;
}

.article-excerpt {
    display: -webkit-box;
    overflow: hidden;
    color: var(--text-secondary);
    font-size: 15px;
    line-height: 1.7;
    -webkit-box-orient: vertical;
    -webkit-line-clamp: 3;
}

.article-more {
    margin-top: auto;
    padding-top: 18px;
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 600;
    transition: color 0.2s ease;
}

.article-item:hover .article-title,
.article-item:hover .article-more {
    color: var(--product-accent);
}

/* ==========================================================================
   Product page hero
   ========================================================================== */

.product-page {
    --product-accent: var(--accent-cosmic);
}

.product-page[data-theme="solar"] {
    --product-accent: var(--accent-solar);
}

.product-hero {
    position: relative;
    display: flex;
    align-items: center;
    min-height: min(88svh, 820px);
    padding: calc(var(--nav-height) + 64px) 0 80px;
    overflow: hidden;
    isolation: isolate;
}

/* NGC 1300 偏左取景，远离右侧视口边缘。土星光环几乎占满原图宽度，改为按原图比例完整显示。 */
.product-hero-media img {
    object-position: 30% 50%;
}

.product-page[data-theme="solar"] .product-hero-media {
    display: flex;
    align-items: center;
}

/* 按原图比例完整显示，上下边缘渐隐，避免星空背景露出矩形边界。 */
.product-page[data-theme="solar"] .product-hero-media img {
    height: auto;
    aspect-ratio: 2430 / 1800;
    -webkit-mask-image: linear-gradient(180deg, transparent 0%, #000 18%, #000 82%, transparent 100%);
    mask-image: linear-gradient(180deg, transparent 0%, #000 18%, #000 82%, transparent 100%);
}

.product-hero-content {
    position: relative;
    z-index: 2;
    min-width: 0;
}

.product-hero h1 {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 14px;
    margin: 0 0 14px;
    font-family: var(--font-display);
    font-size: clamp(56px, 8vw, 110px);
    font-weight: 700;
    letter-spacing: -0.01em;
    line-height: 0.9;
}

.product-hero .product-en {
    order: -1;
    color: var(--text-muted);
    font-family: var(--font-body);
    font-size: 14px;
    font-weight: 500;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.product-hero .product-tagline {
    margin: 0 0 18px;
    color: var(--product-accent);
    font-size: clamp(20px, 2vw, 28px);
    line-height: 1.3;
}

.product-hero .lead {
    max-width: 560px;
    text-wrap: pretty;
}

.product-hero-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 10px 18px;
    margin-top: 24px;
    color: var(--text-muted);
    font-size: 12px;
}

.product-hero-meta span {
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.product-hero-meta span::before {
    content: '';
    width: 4px;
    height: 4px;
    border-radius: 50%;
    background: var(--product-accent);
}

.stats-band-wrap {
    border-bottom: 1px solid var(--line);
}

.stats-band-title {
    padding-top: 24px;
    color: var(--text-muted);
    font-size: 13px;
    line-height: 1.4;
    text-align: center;
}

.stats-band {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
}

.stats-band .stat {
    padding: 28px 16px;
    border-left: 1px solid var(--line);
    text-align: center;
}

.stats-band-title + .stats-band .stat {
    padding-top: 14px;
}

.stats-band .stat:first-child {
    border-left: 0;
}

.stats-band-five {
    grid-template-columns: repeat(5, minmax(0, 1fr));
}

.stats-band dt {
    font-family: var(--font-display);
    font-size: clamp(28px, 2.8vw, 40px);
    font-weight: 700;
    line-height: 1;
}

.stats-band dd {
    margin-top: 8px;
    color: var(--text-muted);
    font-size: 12px;
}

.product-subnav {
    position: sticky;
    top: var(--nav-height);
    z-index: 900;
    border-bottom: 1px solid var(--line);
    background: rgba(0, 0, 0, 0.82);
    backdrop-filter: blur(14px);
}

.product-subnav ul {
    display: flex;
    gap: 24px;
    padding: 14px 0;
    overflow-x: auto;
    list-style: none;
    scrollbar-width: none;
}

.product-subnav ul::-webkit-scrollbar {
    display: none;
}

.product-subnav a {
    color: var(--text-muted);
    font-size: 12px;
    text-decoration: none;
    white-space: nowrap;
}

.product-subnav a:hover {
    color: var(--product-accent);
}

.product-section {
    padding: 96px 0;
    border-top: 1px solid var(--line);
    scroll-margin-top: calc(var(--nav-height) + 56px);
}

.product-section:first-of-type {
    border-top: 0;
}

.product-section-grid {
    display: grid;
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
    gap: 64px;
    align-items: center;
}

.product-section-grid.reverse {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
}

.product-section-grid.reverse .product-section-copy {
    order: 2;
}

.product-section-grid.reverse .product-section-media {
    order: 1;
}

.product-section-copy .section-title {
    font-size: clamp(32px, 4vw, 50px);
}

.product-section-copy .section-desc {
    margin-top: 16px;
}

.feature-list {
    display: grid;
    gap: 0;
    margin-top: 28px;
    border-top: 1px solid var(--line);
}

.feature-item {
    display: grid;
    grid-template-columns: 28px minmax(0, 1fr);
    gap: 14px;
    padding: 18px 0;
    border-bottom: 1px solid var(--line);
}

.feature-index {
    color: var(--product-accent);
    font-family: var(--font-display);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.08em;
}

.feature-item h3 {
    margin-bottom: 4px;
    font-size: 15px;
    font-weight: 600;
}

.feature-item p {
    color: var(--text-secondary);
    font-size: 13px;
}

/* 图文联动（`[data-media-tabs]`）：要点是标签按钮，当前项高亮，底边进度条走完后切到下一张。 */
.feature-tab {
    position: relative;
    width: 100%;
    border-width: 0 0 1px;
    border-style: solid;
    border-color: var(--line);
    background: none;
    color: inherit;
    font: inherit;
    text-align: left;
    cursor: pointer;
    opacity: 0.55;
    transition: opacity 0.25s ease;
}

.feature-tab:hover,
.feature-tab.is-active {
    opacity: 1;
}

.feature-tab:focus-visible {
    outline: 2px solid var(--product-accent);
    outline-offset: 2px;
}

.feature-tab::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -1px;
    width: 0;
    height: 1px;
    background: var(--product-accent);
}

.feature-tab.is-active::after {
    width: 100%;
}

.is-cycling .feature-tab.is-active::after {
    animation: media-tab-progress 6s linear both;
}

@keyframes media-tab-progress {
    from {
        width: 0;
    }
    to {
        width: 100%;
    }
}

.feature-title {
    display: block;
    margin-bottom: 4px;
    font-size: 15px;
    font-weight: 600;
}

.feature-desc {
    display: block;
    color: var(--text-secondary);
    font-size: 13px;
}

/* 图片叠放在同一格里交叉淡入，框高由当前图片决定。 */
.media-tabs-frame {
    display: grid;
}

.media-tabs-slide {
    grid-area: 1 / 1;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.5s ease, visibility 0s linear 0.5s;
}

.media-tabs-slide.is-active {
    opacity: 1;
    visibility: visible;
    transition: opacity 0.5s ease;
}

.product-section-media img,
.product-section-media video {
    width: 100%;
    aspect-ratio: 19 / 9;
    object-fit: cover;
    border: 1px solid var(--line-strong);
    border-radius: var(--radius-md);
    background: #000;
}

/* 视频、轮播图片与 iPad 截图（`.media-native`）按 width/height 的原始比例显示，不裁成 19:9：
   木星飞越 4:3，宇宙之境预览约 2.17:1，轮播图片 16:9，iPad 截图约 1.38:1。 */
.product-section-media video,
.media-tabs-slide img,
.media-native img {
    height: auto;
    aspect-ratio: auto;
    object-fit: contain;
}

.product-section-media figcaption {
    margin-top: 10px;
    color: var(--text-muted);
    font-size: 11px;
}

/* 尺度线：在预览视频下方通栏六等分，连线从第一个刻度中心画到最后一个刻度中心。 */
.scale-ruler {
    position: relative;
    display: grid;
    grid-template-columns: repeat(6, minmax(0, 1fr));
    margin-top: 48px;
    list-style: none;
}

.scale-ruler::before {
    content: '';
    position: absolute;
    top: 5px;
    left: calc(100% / 12);
    right: calc(100% / 12);
    height: 2px;
    background: linear-gradient(90deg, rgba(var(--accent-rgb), 0.3), var(--product-accent));
}

.scale-ruler li {
    position: relative;
    display: grid;
    align-content: start;
    gap: 4px;
    padding: 30px 8px 0;
    text-align: center;
}

.scale-ruler li::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    width: 12px;
    height: 12px;
    margin-left: -6px;
    border: 2px solid var(--product-accent);
    border-radius: 50%;
    background: #000;
}

.scale-ruler li:last-child::before {
    background: var(--product-accent);
}

.scale-ruler-name {
    color: var(--text-primary);
    font-size: clamp(13px, 1.25vw, 15px);
    font-weight: 600;
    line-height: 1.4;
}

.scale-ruler li:last-child .scale-ruler-name {
    color: var(--product-accent);
}

.scale-ruler-span {
    color: var(--text-muted);
    font-size: 13px;
    line-height: 1.4;
}

html:lang(zh) .scale-ruler li {
    word-break: keep-all;
    overflow-wrap: anywhere;
}

.catalog-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1px;
    margin-top: 36px;
    overflow: hidden;
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    background: var(--line);
}

.catalog-grid-four {
    grid-template-columns: repeat(4, minmax(0, 1fr));
}

.catalog-item {
    padding: 24px;
    background: var(--canvas-soft);
}

.catalog-item h3 {
    margin-bottom: 6px;
    font-size: 15px;
    font-weight: 600;
}

.catalog-item p {
    color: var(--text-secondary);
    font-size: 13px;
}

.scene-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
}

.scene-card {
    overflow: hidden;
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    background: #000;
}

.scene-card img {
    width: 100%;
    aspect-ratio: 16 / 9;
    object-fit: cover;
}

.scene-card figcaption {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    padding: 10px 14px;
    color: var(--text-muted);
    font-size: 11px;
}

/* 精选星系：照 App 收藏面板排列，银河系与仙女座星系占两格。 */
.galaxy-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 28px 16px;
    margin-top: 36px;
    list-style: none;
}

.galaxy-card:nth-child(-n + 2) {
    grid-column: span 2;
}

.galaxy-card img {
    width: 100%;
    aspect-ratio: 16 / 9;
    object-fit: cover;
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    background: #000;
}

.galaxy-card-name {
    display: block;
    margin-top: 10px;
    font-size: 15px;
    font-weight: 600;
    line-height: 1.35;
}

.galaxy-card-type {
    display: block;
    margin-top: 2px;
    color: var(--text-muted);
    font-size: 12px;
    line-height: 1.4;
}

.requirements {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    margin-top: 36px;
    overflow: hidden;
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
}

.requirement {
    padding: 22px 24px;
    border-bottom: 1px solid var(--line);
}

.requirement:nth-child(odd) {
    border-right: 1px solid var(--line);
}

.requirement:nth-last-child(-n + 2) {
    border-bottom: 0;
}

.requirement dt {
    margin-bottom: 6px;
    color: var(--text-muted);
    font-size: 11px;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.requirement dd {
    font-size: 15px;
}

.credits-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0 40px;
    margin-top: 32px;
    border-top: 1px solid var(--line);
}

.credit-item {
    padding: 20px 0;
    border-bottom: 1px solid var(--line);
}

.credit-item h3 {
    margin-bottom: 6px;
    font-size: 14px;
    font-weight: 600;
}

.credit-item p {
    color: var(--text-secondary);
    font-size: 13px;
}

.credits-note {
    margin-top: 20px;
    color: var(--text-muted);
    font-size: 12px;
}

.faq-list {
    margin-top: 32px;
    border-top: 1px solid var(--line);
}

.faq-item {
    border-bottom: 1px solid var(--line);
}

.faq-item summary {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    padding: 20px 0;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    list-style: none;
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-item summary::after {
    content: '+';
    color: var(--product-accent);
    font-size: 20px;
    font-weight: 300;
    line-height: 1;
}

.faq-item[open] summary::after {
    content: '−';
}

.faq-answer {
    max-width: 760px;
    padding: 0 0 22px;
    color: var(--text-secondary);
    font-size: 14px;
}

.legal-links {
    display: flex;
    flex-wrap: wrap;
    gap: 12px 22px;
    margin-top: 24px;
    list-style: none;
}

.legal-links a {
    color: var(--text-muted);
    font-size: 12px;
    text-decoration: none;
}

.legal-links a:hover {
    color: var(--text-primary);
}

.more-product {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 32px;
    padding: 40px;
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    background: linear-gradient(120deg, rgba(27, 60, 83, 0.28), rgba(0, 0, 0, 0.06));
}

.more-product h2 {
    margin-bottom: 8px;
    font-family: var(--font-display);
    font-size: clamp(28px, 3vw, 40px);
    font-weight: 700;
    line-height: 1;
}

.more-product p {
    color: var(--text-secondary);
    font-size: 14px;
}

.final-cta {
    padding: 112px 0;
    border-top: 1px solid var(--line);
    text-align: center;
}

.final-cta h2 {
    margin: 0 auto 18px;
    font-family: var(--font-display);
    font-size: clamp(34px, 4.8vw, 64px);
    font-weight: 700;
    line-height: 0.98;
}

html:lang(zh) .final-cta h2 {
    line-height: 1.2;
}

/* 两句各自不断开，放不下时整句换到下一行。 */
.final-cta-title {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    column-gap: 0.26em;
}

html:lang(zh) .final-cta-title {
    column-gap: 0;
}

.final-cta p {
    color: var(--text-secondary);
}

.final-cta .button-row {
    justify-content: center;
}

/* ==========================================================================
   WeChat download guide
   ========================================================================== */

.wechat-guide {
    position: fixed;
    inset: 0;
    z-index: 3000;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 32px;
    background: rgba(0, 0, 0, 0.9);
    text-align: center;
}

.wechat-guide-arrow {
    position: absolute;
    top: 16px;
    right: 28px;
    color: var(--soft-cream);
    font-size: 56px;
    line-height: 1;
}

.wechat-guide-title {
    margin-bottom: 12px;
    font-family: var(--font-display);
    font-size: clamp(28px, 5vw, 44px);
    font-weight: 700;
}

.wechat-guide-text {
    max-width: 440px;
    color: var(--text-secondary);
    font-size: 15px;
}

.wechat-guide-close {
    position: absolute;
    bottom: 32px;
    left: 50%;
    width: 40px;
    height: 40px;
    border: 1px solid var(--line-strong);
    border-radius: 50%;
    background: transparent;
    color: var(--text-primary);
    font-size: 22px;
    line-height: 1;
    cursor: pointer;
    transform: translateX(-50%);
}

/* ==========================================================================
   Responsive
   ========================================================================== */

@media (max-width: 1100px) {
    .app-card-body {
        padding: 28px 24px 32px;
    }

    .sources {
        grid-template-columns: 1fr;
        gap: 28px;
    }

    .footer-grid {
        grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
        gap: 24px;
    }
}

@media (max-width: 900px) {
    .navbar-inner {
        gap: 12px;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        position: absolute;
        top: var(--nav-height);
        left: 0;
        right: 0;
        display: none;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        margin: 0;
        padding: 16px 24px 24px;
        border-bottom: 1px solid var(--line);
        background: rgba(0, 0, 0, 0.97);
    }

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

    .nav-menu a {
        display: block;
        padding: 14px 0;
        border-bottom: 1px solid var(--line);
        font-size: 15px;
    }

    .nav-menu a.is-active::after {
        display: none;
    }

    .nav-menu a.is-active {
        color: var(--product-accent);
    }

    .language-switch {
        margin-left: auto;
    }

    /* 窄屏：星系置于文字上方，标题压在画面底部的渐隐区。 */
    .home-hero,
    .product-hero {
        display: block;
        min-height: 0;
        padding: calc(var(--nav-height) + min(44vw, 360px)) 0 72px;
    }

    .home-hero-media,
    .product-hero-media {
        left: 0;
        right: 0;
        bottom: auto;
        width: 100%;
        height: min(84vw, 640px);
    }

    .home-hero-media img {
        object-position: 58% 55%;
    }

    .product-hero-media img,
    .product-page[data-theme="solar"] .product-hero-media img {
        object-position: 50% 50%;
    }

    .home-hero-media::after,
    .product-hero-media::after {
        background:
            linear-gradient(0deg, #000 0%, rgba(0, 0, 0, 0.55) 34%, transparent 66%),
            linear-gradient(180deg, rgba(0, 0, 0, 0.7) 0%, transparent 24%);
    }

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

    /* 竖向轴：刻度在上，区间图例与注释在下。 */
    .scale-span {
        display: flex;
        flex-direction: column;
        max-width: 520px;
    }

    .scale-ranges {
        order: 1;
    }

    .scale-span-note {
        order: 2;
    }

    .scale-ticks {
        grid-template-columns: 1fr;
        grid-auto-rows: 1fr;
    }

    .scale-ticks::before {
        top: calc(100% / 14);
        bottom: calc(100% / 14);
        left: 5px;
        right: auto;
        width: 2px;
        height: auto;
        background: linear-gradient(180deg, var(--accent-solar) 0 16.667%, var(--accent-cosmic) 16.667% 100%);
    }

    .scale-ticks li {
        grid-template-columns: minmax(0, 1fr) auto;
        align-items: baseline;
        gap: 12px;
        padding: 10px 0 10px 32px;
        text-align: left;
    }

    .scale-tick-span {
        text-align: right;
    }

    .scale-ticks li::before {
        top: 50%;
        left: 0;
        margin: -6px 0 0;
    }

    .scale-ranges {
        display: flex;
        flex-direction: column;
        gap: 10px;
        margin: 28px 0 0;
    }

    .scale-range {
        justify-content: flex-start;
        min-height: 44px;
        margin: 0;
        padding-block: 10px;
        text-align: left;
    }

    .sources {
        margin-top: 72px;
    }

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

    .article-item {
        padding-bottom: 28px;
    }

    .product-section-grid,
    .product-section-grid.reverse {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .product-section-grid.reverse .product-section-copy,
    .product-section-grid.reverse .product-section-media {
        order: initial;
    }

    /* 竖向尺度线：刻度在左，跨度右对齐。 */
    .scale-ruler {
        grid-template-columns: 1fr;
        grid-auto-rows: 1fr;
        max-width: 520px;
        margin-top: 36px;
    }

    .scale-ruler::before {
        top: calc(100% / 12);
        bottom: calc(100% / 12);
        left: 5px;
        right: auto;
        width: 2px;
        height: auto;
        background: linear-gradient(180deg, rgba(var(--accent-rgb), 0.3), var(--product-accent));
    }

    .scale-ruler li {
        grid-template-columns: minmax(0, 1fr) auto;
        align-items: baseline;
        gap: 12px;
        padding: 10px 0 10px 32px;
        text-align: left;
    }

    .scale-ruler li::before {
        top: 50%;
        left: 0;
        margin: -6px 0 0;
    }

    .scale-ruler-name {
        font-size: 15px;
    }

    .scale-ruler-span {
        text-align: right;
    }

    .catalog-grid,
    .catalog-grid-four {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .galaxy-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
        gap: 22px 12px;
    }

    .galaxy-card:nth-child(-n + 2) {
        grid-column: auto;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 32px;
    }

    .footer-brand {
        grid-column: 1 / -1;
    }

    .more-product {
        align-items: flex-start;
        flex-direction: column;
        padding: 28px;
    }
}

@media (max-width: 640px) {
    :root {
        --nav-height: 64px;
    }

    .container,
    .navbar-inner,
    .footer-grid,
    .footer-bottom {
        width: min(100% - 32px, var(--container));
    }

    .section {
        padding: 72px 0;
    }

    .section-head {
        margin-bottom: 36px;
    }

    .display {
        font-size: clamp(42px, 12vw, 64px);
    }

    html:lang(zh) .home-hero-title {
        font-size: clamp(32px, 10vw, 48px);
    }

    html:lang(en) .home-hero-title {
        font-size: clamp(34px, 10.6vw, 56px);
    }

    .brand-logo {
        width: 160px;
    }

    .home-hero {
        padding: calc(var(--nav-height) + 50vw) 0 24px;
    }

    .product-hero {
        padding: calc(var(--nav-height) + 50vw) 0 48px;
    }

    /* 图框接近图片比例（约 1.38:1），星系左右留出空间，不被裁切。 */
    .home-hero-media,
    .product-hero-media {
        height: 74vw;
    }

    .hero-apps {
        grid-template-columns: 1fr;
        margin-top: 32px;
    }

    .app-card-body {
        padding: 24px 20px 28px;
    }

    .app-stats {
        gap: 14px;
    }

    .sources-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .articles-head {
        align-items: flex-start;
        flex-direction: column;
        gap: 16px;
    }

    .button-row {
        gap: 10px;
    }

    .btn {
        min-height: 44px;
    }

    .product-hero h1 {
        gap: 10px;
    }

    .stats-band {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .stats-band .stat {
        padding: 20px 12px;
        border-bottom: 1px solid var(--line);
    }

    /* 有标题时只收紧第一行的上边距，第二行保持 20px。 */
    .stats-band-title + .stats-band .stat:nth-child(n + 3) {
        padding-top: 20px;
    }

    .stats-band .stat:nth-child(odd) {
        border-left: 0;
    }

    .stats-band .stat:nth-last-child(-n + 2) {
        border-bottom: 0;
    }

    /* 五格：上排三格、下排两格。写在两列规则之后，覆盖其竖线与底边。 */
    .stats-band-five {
        grid-template-columns: repeat(6, minmax(0, 1fr));
    }

    .stats-band-five .stat {
        grid-column: span 2;
    }

    .stats-band-five .stat:nth-child(n + 4) {
        grid-column: span 3;
    }

    .stats-band-five .stat:nth-child(odd) {
        border-left: 1px solid var(--line);
    }

    .stats-band-five .stat:nth-child(1),
    .stats-band-five .stat:nth-child(4) {
        border-left: 0;
    }

    .stats-band-five .stat:nth-child(-n + 3) {
        border-bottom: 1px solid var(--line);
    }

    .stats-band-five .stat:nth-child(n + 4) {
        border-bottom: 0;
    }

    .stats-band-title + .stats-band-five .stat:nth-child(3) {
        padding-top: 14px;
    }

    .stats-band-title + .stats-band-five .stat:nth-child(n + 4) {
        padding-top: 20px;
    }

    .product-subnav ul {
        gap: 18px;
        padding-right: 24px;
        mask-image: linear-gradient(90deg, #000 0%, #000 86%, transparent 100%);
        -webkit-mask-image: linear-gradient(90deg, #000 0%, #000 86%, transparent 100%);
    }

    .product-section {
        padding: 64px 0;
    }

    .product-section .section-title {
        font-size: clamp(28px, 7.6vw, 44px);
    }

    .catalog-grid,
    .catalog-grid-four {
        grid-template-columns: 1fr;
    }

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

    .requirement,
    .requirement:nth-child(odd),
    .requirement:nth-last-child(-n + 2) {
        border-right: 0;
        border-bottom: 1px solid var(--line);
    }

    .requirement:last-child {
        border-bottom: 0;
    }

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

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

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

    .footer-brand {
        grid-column: auto;
    }

    .footer-bottom {
        margin-top: 36px;
    }

    .final-cta {
        padding: 72px 0;
    }
}

@media (max-width: 480px) {
    .app-stats {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .app-stats li {
        grid-template-columns: 120px minmax(0, 1fr);
        align-items: baseline;
        gap: 14px;
    }

    .stat-value,
    html:lang(zh) .stat-value {
        font-size: 22px;
    }
}

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

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }

    .reveal.is-visible {
        animation: none;
    }
}