:root {
    --font-body: "Avenir Next", "SF Pro Display", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    --font-display: var(--font-body);
    --bg: #f4f7fb;
    --bg-secondary: #eaf0fb;
    --hero-bg: rgba(255, 255, 255, 0.78);
    --surface: rgba(255, 255, 255, 0.84);
    --surface-strong: rgba(255, 255, 255, 0.97);
    --surface-soft: rgba(255, 255, 255, 0.68);
    --text: #172033;
    --text-muted: #58657b;
    --heading: #0d1526;
    --accent: #2f6df6;
    --accent-strong: #1649d6;
    --accent-soft: rgba(47, 109, 246, 0.12);
    --line: rgba(23, 32, 51, 0.08);
    --line-strong: rgba(23, 32, 51, 0.14);
    --shadow: 0 30px 70px rgba(15, 23, 42, 0.13);
    --shadow-soft: 0 18px 42px rgba(15, 23, 42, 0.08);
    --radius-xl: 14px;
    --radius-lg: 10px;
    --radius-md: 8px;
    --content-max: 1160px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    color: var(--text);
    line-height: 1.72;
    min-height: 100vh;
    background:
        radial-gradient(circle at top left, rgba(47, 109, 246, 0.14), transparent 28%),
        radial-gradient(circle at 85% 10%, rgba(255, 255, 255, 0.82), transparent 30%),
        linear-gradient(180deg, var(--bg) 0%, var(--bg-secondary) 100%);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

body::before,
body::after {
    content: "";
    position: fixed;
    width: 24rem;
    height: 24rem;
    border-radius: var(--radius-xl);
    filter: blur(70px);
    opacity: 0.55;
    pointer-events: none;
    z-index: 0;
}

body::before {
    top: -7rem;
    left: -6rem;
    background: var(--accent-soft);
}

body::after {
    right: -8rem;
    bottom: 10rem;
    background: rgba(255, 255, 255, 0.58);
}

body > * {
    position: relative;
    z-index: 1;
}

.container,
.footer-content,
.footer-shell,
.header-shell,
.hero-shell,
.tile-tabs-shell {
    width: min(var(--content-max), calc(100% - 40px));
    margin: 0 auto;
}

section {
    padding: 108px 0;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 10;
    padding: 0;
    border-bottom: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.9);
    box-shadow: 0 8px 24px rgba(17, 24, 39, 0.04);
    backdrop-filter: blur(18px);
}

.header-shell {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    padding: 14px 32px;
}

.header-left,
.header-right,
.header-nav,
.language-menu {
    display: flex;
    align-items: center;
}

.header-left,
.header-right {
    gap: 18px;
}

.header-nav {
    gap: 8px;
    flex-wrap: wrap;
}

.brand-mark {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding-right: 18px;
    border-right: 1px solid var(--line);
    text-decoration: none;
    font-family: var(--font-display);
    color: var(--heading);
    font-size: 1.05rem;
    font-weight: 600;
    letter-spacing: -0.045em;
    line-height: 1;
}

.brand-mark img {
    width: 34px;
    height: 34px;
    border-radius: 8px;
    object-fit: cover;
    background: transparent;
    border: 0;
    padding: 0;
    display: block;
}

.header-nav a,
.header-nav-coming-soon {
    display: inline-flex;
    align-items: center;
    position: relative;
    min-height: 38px;
    padding: 0 14px;
    border-radius: var(--radius-lg);
    color: color-mix(in srgb, var(--heading) 86%, var(--text-muted));
    font-size: 14px;
    font-weight: 400;
    transition:
        color 0.2s ease,
        background-color 0.2s ease,
        transform 0.2s ease;
}

.header-nav a {
    text-decoration: none;
}

.header-nav a:hover {
    color: var(--heading);
    background: rgba(255, 255, 255, 0.78);
    transform: translateY(-1px);
}

.header-nav-coming-soon {
    cursor: default;
}

.header-nav-coming-soon:hover {
    color: var(--heading);
    background: rgba(255, 255, 255, 0.78);
    transform: translateY(-1px);
}

.header-nav-tooltip {
    position: absolute;
    left: 50%;
    top: calc(100% + 8px);
    transform: translateX(-50%) translateY(4px);
    padding: 6px 10px;
    border: 1px solid var(--line);
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.96);
    color: var(--heading);
    font-size: 12px;
    line-height: 1;
    white-space: nowrap;
    box-shadow: 0 12px 24px rgba(17, 24, 39, 0.08);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease;
}

.header-nav-coming-soon:hover .header-nav-tooltip {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

.header-icon-soon {
    min-width: 38px;
    justify-content: center;
    padding: 0 10px;
}

.header-icon-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 18px;
    height: 18px;
    color: inherit;
}

.header-icon-link svg {
    display: block;
    width: 100%;
    height: 100%;
}

.language-toggle {
    appearance: none;
    border: 0;
    background: transparent;
    color: color-mix(in srgb, var(--heading) 60%, var(--text-muted));
    min-height: 38px;
    padding: 0 2px;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    cursor: pointer;
    font: inherit;
    font-size: 13px;
    font-weight: 400;
    transition:
        transform 0.22s ease,
        color 0.22s ease,
        opacity 0.22s ease;
}

.language-toggle:hover {
    transform: translateY(-1px);
    color: var(--heading);
}

.language-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 15px;
    height: 15px;
    color: currentColor;
    opacity: 0.92;
    line-height: 1;
    flex-shrink: 0;
}

.language-icon svg {
    display: block;
    width: 100%;
    height: 100%;
}

.language-label {
    color: inherit;
    font-size: 13px;
    font-weight: 400;
}

.language-menu {
    position: relative;
}

.language-dropdown {
    position: absolute;
    top: calc(100% + 10px);
    right: 0;
    min-width: 164px;
    padding: 8px;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    background: rgba(255, 255, 255, 0.96);
    box-shadow: 0 18px 38px rgba(17, 24, 39, 0.1);
    backdrop-filter: blur(18px);
    display: none;
}

.language-menu.is-open .language-dropdown {
    display: grid;
    gap: 2px;
}

.language-option {
    appearance: none;
    width: 100%;
    border: 0;
    background: transparent;
    border-radius: var(--radius-md);
    min-height: 38px;
    padding: 0 10px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    color: color-mix(in srgb, var(--heading) 84%, var(--text-muted));
    cursor: pointer;
    font: inherit;
    font-size: 13px;
    font-weight: 400;
    text-align: left;
    transition:
        background-color 0.2s ease,
        color 0.2s ease;
}

.language-option:hover {
    background: rgba(17, 24, 39, 0.05);
    color: var(--heading);
}

.language-check {
    opacity: 0;
    color: var(--heading);
    width: 14px;
    height: 14px;
    line-height: 1;
    transform: translateY(-0.5px);
    flex-shrink: 0;
}

.language-check svg {
    display: block;
    width: 100%;
    height: 100%;
}

.language-option.is-selected .language-check {
    opacity: 1;
}

.hero {
    min-height: calc(100vh - 96px);
    display: flex;
    align-items: center;
    padding: 48px 0 92px;
}

.hero-shell {
    position: relative;
}

.hero-layout {
    display: grid;
    gap: 36px;
}

.hero-headline {
    max-width: none;
    display: flex;
    justify-content: center;
    text-align: center;
}

.hero-grid {
    display: grid;
    grid-template-columns: minmax(0, 0.78fr) minmax(420px, 1.22fr);
    gap: 72px;
    align-items: center;
}

.hero-copy,
.hero-visual-frame,
.form-container,
.footer-column,
.signal-card,
.stack-frame-box,
.tile-tabs-shell .tab-panel {
    transition:
        transform 0.35s cubic-bezier(0.22, 1, 0.36, 1),
        box-shadow 0.35s cubic-bezier(0.22, 1, 0.36, 1),
        border-color 0.25s ease,
        background-color 0.25s ease;
}

.hero-visual {
    position: relative;
}

.hero-visual-frame {
    padding: 0;
    border-radius: 0;
    background: transparent;
    border: 0;
    box-shadow: none;
    backdrop-filter: none;
}

.hero-visual-frame img {
    display: block;
    width: 100%;
    height: auto;
    border-radius: var(--radius-lg);
    box-shadow: 0 20px 44px rgba(15, 23, 42, 0.08);
}

.section-kicker {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
    color: var(--accent-strong);
    font-size: 12px;
    font-weight: 800;
    letter-spacing: 0.16em;
    text-transform: uppercase;
}

.hero h1,
.section-title h2,
.form-container h2,
.stats-header h3,
.footer-column h4 {
    font-family: var(--font-display);
    color: var(--heading);
}

.hero h1 {
    max-width: none;
    font-size: clamp(2.5rem, 4.1vw, 4.35rem);
    line-height: 0.98;
    letter-spacing: -0.055em;
    margin-bottom: 0;
    white-space: nowrap;
}

.hero .description {
    max-width: 460px;
    margin: 0 0 18px;
    font-size: clamp(1rem, 1.2vw, 1.08rem);
    line-height: 1.9;
    color: color-mix(in srgb, var(--heading) 78%, var(--text-muted));
}

.hero-support {
    max-width: 500px;
    margin-bottom: 34px;
    display: grid;
    gap: 18px;
}

.hero-support p {
    font-size: 1rem;
    line-height: 1.85;
    color: color-mix(in srgb, var(--heading) 78%, var(--text-muted));
}

.hero-points {
    list-style: none;
    display: grid;
    gap: 10px;
}

.hero-points li {
    position: relative;
    padding-left: 16px;
    color: var(--text-muted);
    font-size: 0.96rem;
    line-height: 1.7;
}

.hero-points li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0.72em;
    width: 5px;
    height: 5px;
    border-radius: 999px;
    background: color-mix(in srgb, var(--heading) 38%, var(--text-muted));
}

.buttons {
    display: flex;
    justify-content: flex-start;
    gap: 14px;
    flex-wrap: wrap;
}

.btn,
.submit-btn {
    appearance: none;
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    text-decoration: none;
    cursor: pointer;
    font: inherit;
    font-weight: 700;
    letter-spacing: 0.01em;
    transition:
        transform 0.22s ease,
        box-shadow 0.25s ease,
        background-color 0.25s ease,
        border-color 0.25s ease,
        color 0.25s ease;
}

.btn {
    min-width: 156px;
    padding: 16px 26px;
    font-size: 15px;
}

.buttons .btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.buttons .btn::before {
    content: "";
    display: block;
    width: 14px;
    height: 14px;
    background-repeat: no-repeat;
    background-position: center;
    background-size: 14px 14px;
    flex-shrink: 0;
}

.buttons .btn-primary::before {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none' stroke='white' stroke-width='1.5' stroke-linecap='square' stroke-linejoin='miter'%3E%3Cpath d='M8 2.5v7.2'/%3E%3Cpath d='M5.2 7.1 8 9.9l2.8-2.8'/%3E%3Cpath d='M3 12.5h10'/%3E%3C/svg%3E");
}

.buttons .btn-secondary::before {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none' stroke='%23111827' stroke-width='1.4' stroke-linecap='square' stroke-linejoin='miter'%3E%3Crect x='2.5' y='2.5' width='4.25' height='4.25'/%3E%3Crect x='9.25' y='2.5' width='4.25' height='4.25'/%3E%3Crect x='2.5' y='9.25' width='4.25' height='4.25'/%3E%3Crect x='9.25' y='9.25' width='4.25' height='4.25'/%3E%3C/svg%3E");
}

.btn:hover,
.submit-btn:hover {
    transform: translateY(-2px);
}

.btn:active,
.submit-btn:active {
    transform: translateY(0);
}

.btn-primary,
.submit-btn {
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-strong) 100%);
    color: #fff;
    box-shadow: 0 18px 38px rgba(0, 0, 0, 0.16);
}

.btn-primary:hover,
.submit-btn:hover {
    box-shadow: 0 22px 42px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
    background: var(--surface-strong);
    color: var(--heading);
    border-color: var(--line-strong);
    box-shadow: 0 12px 28px rgba(15, 23, 42, 0.08);
}

.btn-secondary:hover {
    background: var(--surface);
    border-color: var(--accent);
    color: var(--accent-strong);
}

.product-section,
.stats-section {
    background: linear-gradient(180deg, transparent 0%, rgba(255, 255, 255, 0.2) 100%);
}

.features-section,
.contact-section {
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.24) 0%, transparent 100%);
}

.section-title,
.stats-header {
    text-align: center;
    max-width: 820px;
    margin: 0 auto 60px;
}

.section-title h2 {
    font-size: clamp(2.25rem, 4vw, 3.45rem);
    line-height: 1.02;
    letter-spacing: -0.05em;
    margin-bottom: 14px;
}

.form-container h2 {
    font-size: clamp(1.82rem, 3vw, 2.55rem);
    line-height: 1.08;
    letter-spacing: -0.04em;
    margin-bottom: 14px;
}

.section-title p,
.stats-header p,
.form-container .form-description {
    color: var(--text-muted);
    font-size: 17px;
    line-height: 1.78;
}

.form-container,
.footer-column {
    background: var(--surface);
    border: 1px solid var(--line);
    box-shadow: var(--shadow-soft);
    backdrop-filter: blur(16px);
}

.form-container {
    max-width: 640px;
    margin: 0 auto;
    border-radius: calc(var(--radius-xl) + 2px);
    padding: clamp(32px, 4vw, 48px);
}

.download-heading {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    gap: 18px;
}

.download-heading h2 {
    margin-bottom: 0;
}

.download-beta {
    flex-shrink: 0;
    display: inline-flex;
    align-items: center;
    min-height: 28px;
    padding: 0 10px;
    border: 1px solid var(--line);
    border-radius: 999px;
    background: var(--surface-strong);
    color: color-mix(in srgb, var(--heading) 78%, var(--text-muted));
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.06em;
}

.contact-section .form-container {
    max-width: 1020px;
}

.download-layout {
    display: grid;
    grid-template-columns: minmax(0, 1.55fr) minmax(240px, 0.82fr);
    gap: 24px;
    align-items: stretch;
    margin-top: 40px;
}

.download-options {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
}

.download-card,
.download-wechat {
    border: 1px solid var(--line);
    border-radius: calc(var(--radius-lg) + 2px);
    background: var(--surface-strong);
    box-shadow: var(--shadow-soft);
}

.download-card {
    padding: 22px;
    display: grid;
    gap: 16px;
    align-content: start;
    grid-template-rows: auto auto 1fr auto;
}

.download-card-header {
    display: block;
}

.download-card-header h3,
.download-wechat h3 {
    font-size: 1.1rem;
    line-height: 1.15;
    color: var(--heading);
}

.download-card p,
.download-wechat p {
    color: var(--text-muted);
    font-size: 14px;
    line-height: 1.7;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    width: 100%;
    min-width: 0;
    margin-top: 12px;
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-strong) 100%);
    color: #fff;
    border-color: transparent;
    box-shadow: 0 18px 38px rgba(0, 0, 0, 0.16);
}

.download-btn:hover {
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-strong) 100%);
    color: #fff;
    border-color: transparent;
    box-shadow: 0 22px 42px rgba(0, 0, 0, 0.2);
}

.download-btn::before {
    content: "";
    display: block;
    width: 14px;
    height: 14px;
    background-repeat: no-repeat;
    background-position: center;
    background-size: 14px 14px;
    flex-shrink: 0;
}

.download-btn-windows::before {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none' stroke='white' stroke-width='1.2' stroke-linecap='square' stroke-linejoin='miter'%3E%3Cpath d='M2.5 3.2 7.1 2.5v4.6H2.5V3.2Z'/%3E%3Cpath d='M8.5 2.3 13.5 1.6v5.5h-5V2.3Z'/%3E%3Cpath d='M2.5 8.9h4.6v4.6l-4.6-.7V8.9Z'/%3E%3Cpath d='M8.5 8.9h5v5.5l-5-.7V8.9Z'/%3E%3C/svg%3E");
}

.download-btn-mac::before {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none' stroke='white' stroke-width='1.35' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M9.4 2.5c.5-.6 1.4-1 2.1-.9.1.8-.2 1.6-.7 2.1-.5.6-1.4 1-2.1.9-.1-.8.2-1.5.7-2.1Z'/%3E%3Cpath d='M10.8 8.3c0-1.6 1.3-2.4 1.4-2.5-.8-1.1-1.9-1.2-2.3-1.2-1-.1-1.9.6-2.4.6-.5 0-1.2-.6-2-.6-1 0-1.9.6-2.4 1.4-1.1 1.8-.3 4.4.7 5.8.5.7 1 1.5 1.8 1.4.7 0 1-.5 1.9-.5.9 0 1.1.5 1.9.5.8 0 1.3-.7 1.8-1.4.6-.9.8-1.8.8-1.9-.1 0-1.2-.5-1.2-1.8Z'/%3E%3C/svg%3E");
}

.download-wechat {
    padding: 20px;
    display: grid;
    justify-items: center;
    align-content: center;
    text-align: center;
    gap: 12px;
}

.download-wechat img {
    width: min(100%, 144px);
    border-radius: 14px;
    display: block;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 10px;
    font-size: 13px;
    font-weight: 700;
    color: var(--heading);
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.form-group input {
    width: 100%;
    padding: 16px 18px;
    border-radius: var(--radius-md);
    border: 1px solid var(--line);
    background: var(--surface-strong);
    color: var(--heading);
    font: inherit;
    font-size: 16px;
    outline: none;
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.5);
    transition:
        border-color 0.22s ease,
        box-shadow 0.22s ease,
        transform 0.22s ease,
        background-color 0.22s ease;
}

.form-group input::placeholder {
    color: #97a2b4;
}

.form-group input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 4px var(--accent-soft);
    transform: translateY(-1px);
}

.form-group input.input-error {
    border-color: #db4d6d;
    box-shadow: 0 0 0 4px rgba(219, 77, 109, 0.12);
}

.submit-btn {
    width: 100%;
    margin-top: 8px;
    padding: 17px 22px;
    font-size: 15px;
}

.submit-btn.is-success {
    background: linear-gradient(135deg, #2ea97b, #1f8a63);
}

.privacy-note {
    text-align: center;
    font-size: 13px;
    margin-top: 16px;
    color: var(--text-muted);
}

.error-msg,
.success-msg {
    display: none;
    border-radius: var(--radius-md);
    padding: 14px 16px;
    margin-top: 14px;
    font-size: 14px;
}

.error-msg.show,
.success-msg.show {
    display: block;
    animation: lift-in 0.35s ease;
}

.error-msg {
    color: #b63d59;
    background: rgba(255, 235, 240, 0.9);
    border: 1px solid rgba(182, 61, 89, 0.18);
}

.success-msg {
    color: #176c4f;
    background: rgba(231, 251, 243, 0.92);
    border: 1px solid rgba(23, 108, 79, 0.16);
}

footer {
    padding: 0 0 40px;
}

.footer-shell {
    padding: 0 32px;
}

.footer-content {
    padding: 30px 32px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 18px;
}

.footer-column {
    padding: 0;
    background: transparent;
    border: 0;
    box-shadow: none;
    backdrop-filter: none;
}

.tile-tabs-shell .tab-panel:hover,
.stack-frame-box:hover,
.signal-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow);
}

.footer-column h4 {
    font-size: 15px;
    letter-spacing: 0.02em;
    margin-bottom: 14px;
}

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

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

.footer-column a:hover {
    color: var(--accent-strong);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
    padding-top: 22px;
    margin-top: 24px;
    border-top: 1px solid var(--line);
    color: var(--text-muted);
    font-size: 13px;
}

.footer-bottom p {
    margin: 0;
}

.footer-bottom a {
    color: inherit;
    text-decoration: none;
}

.footer-bottom a:hover {
    color: inherit;
    text-decoration: none;
}

.footer-wechat {
    position: relative;
    display: inline-flex;
    align-items: center;
}

.footer-wechat-trigger {
    appearance: none;
    border: 0;
    background: transparent;
    padding: 0;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    color: var(--text-muted);
    cursor: pointer;
    text-align: left;
    transition: color 0.2s ease, transform 0.2s ease;
}

.footer-wechat-trigger:hover,
.footer-wechat:focus-within .footer-wechat-trigger {
    color: var(--heading);
    transform: translateY(-1px);
}

.footer-wechat-trigger svg {
    width: 22px;
    height: 22px;
    fill: currentColor;
    display: block;
    flex-shrink: 0;
}

.footer-wechat-label {
    display: inline-flex;
    align-items: center;
    line-height: 1.15;
}

.footer-wechat-label span {
    font-size: 13px;
    color: var(--heading);
}

.footer-wechat-popover {
    position: absolute;
    right: 0;
    bottom: calc(100% + 14px);
    display: grid;
    justify-items: center;
    gap: 10px;
    padding: 14px 14px 12px;
    border: 1px solid var(--line);
    border-radius: 16px;
    background: rgba(255, 255, 255, 0.96);
    box-shadow: 0 18px 42px rgba(17, 24, 39, 0.12);
    backdrop-filter: blur(18px);
    opacity: 0;
    visibility: hidden;
    transform: translateY(6px);
    transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease;
    pointer-events: none;
}

.footer-wechat:hover .footer-wechat-popover,
.footer-wechat:focus-within .footer-wechat-popover {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.footer-wechat-popover img {
    width: 140px;
    height: 140px;
    display: block;
    border-radius: 10px;
    object-fit: cover;
}

.footer-wechat-popover span {
    font-size: 13px;
    line-height: 1;
    color: var(--heading);
    white-space: nowrap;
}

.reveal-item {
    opacity: 0;
    transform: translateY(28px);
    transition:
        opacity 0.8s cubic-bezier(0.22, 1, 0.36, 1),
        transform 0.8s cubic-bezier(0.22, 1, 0.36, 1),
        box-shadow 0.35s cubic-bezier(0.22, 1, 0.36, 1),
        border-color 0.25s ease,
        background-color 0.25s ease;
}

.reveal-item.is-visible {
    opacity: 1;
    transform: translateY(0);
}

body.theme-minimal {
    --font-body: "Neue Haas Grotesk Text Pro", "Helvetica Neue", "PingFang SC", Arial, sans-serif;
    --font-display: "Neue Haas Grotesk Display Pro", "Helvetica Neue", "PingFang SC", sans-serif;
    --bg: #eef1f5;
    --bg-secondary: #f8fafc;
    --hero-bg: rgba(255, 255, 255, 0.9);
    --surface: rgba(255, 255, 255, 0.92);
    --surface-strong: rgba(255, 255, 255, 0.98);
    --surface-soft: rgba(255, 255, 255, 0.84);
    --text: #1f2937;
    --text-muted: #5b6473;
    --heading: #111827;
    --accent: #111827;
    --accent-strong: #000000;
    --accent-soft: rgba(17, 24, 39, 0.09);
    --line: rgba(17, 24, 39, 0.08);
    --line-strong: rgba(17, 24, 39, 0.14);
    --shadow: 0 18px 42px rgba(17, 24, 39, 0.1);
    --shadow-soft: 0 10px 24px rgba(17, 24, 39, 0.06);
    --radius-xl: 14px;
    --radius-lg: 10px;
}

.tab-panel {
    display: none;
}

.tab-panel.is-active {
    display: block;
}

.ecosystem-section .section-title,
.framed-features .section-title,
.selling-section .stats-header {
    margin-bottom: 34px;
}

.stack-frame-shell {
    display: grid;
    gap: 20px;
}

.stack-frame-item {
    display: grid;
    gap: 14px;
}

.stack-frame-heading {
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 18px 20px;
}

.stack-frame-heading h3 {
    font-family: var(--font-display);
    font-size: clamp(1.45rem, 2vw, 1.95rem);
    line-height: 1.08;
    letter-spacing: -0.03em;
    color: var(--heading);
}

.stack-frame-box {
    display: grid;
    grid-template-columns: minmax(0, 0.92fr) minmax(320px, 1.08fr);
    gap: 22px;
    padding: 22px;
    border: 1px solid var(--line);
    border-radius: calc(var(--radius-xl) + 2px);
    background: var(--surface);
    box-shadow: var(--shadow-soft);
}

.stack-frame-box.is-reverse {
    grid-template-columns: minmax(320px, 1.08fr) minmax(0, 0.92fr);
}

.stack-frame-copy {
    display: grid;
    align-content: start;
    gap: 18px;
}

.stack-frame-copy p,
.signal-card p,
.tile-panel-copy p {
    color: var(--text-muted);
    line-height: 1.8;
}

.stack-frame-list {
    list-style: none;
    display: grid;
    gap: 12px;
}

.stack-frame-list li {
    position: relative;
    padding: 14px 16px 14px 42px;
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    background: var(--surface-strong);
    color: var(--text-muted);
}

.stack-frame-list li::before {
    content: "";
    position: absolute;
    left: 18px;
    top: 20px;
    width: 8px;
    height: 8px;
    border-radius: 999px;
    background: linear-gradient(135deg, var(--accent), var(--accent-strong));
    box-shadow: 0 0 0 6px var(--accent-soft);
}

.stack-frame-visual {
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.stack-frame-visual img {
    width: 100%;
    height: auto;
    display: block;
}

.signal-board {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 18px;
}

.signal-card {
    padding: 24px 20px;
    border: 1px solid var(--line);
    border-radius: calc(var(--radius-xl) + 2px);
    background: var(--surface);
    box-shadow: var(--shadow-soft);
}

.signal-card span {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 14px;
    color: var(--accent-strong);
    font-size: 12px;
    font-weight: 800;
    letter-spacing: 0.14em;
    text-transform: uppercase;
}

.signal-card span::before {
    content: "";
    width: 18px;
    height: 1px;
    background: currentColor;
    opacity: 0.4;
}

.signal-card h4 {
    font-family: var(--font-display);
    font-size: 1.4rem;
    line-height: 1.08;
    letter-spacing: -0.04em;
    color: var(--heading);
    margin-bottom: 10px;
}

.tile-tabs-shell {
    display: grid;
    gap: 18px;
}

.tile-tabs-nav {
    display: flex;
    gap: 12px;
    overflow-x: auto;
    overflow-y: hidden;
    padding-bottom: 6px;
    scrollbar-width: thin;
    scrollbar-color: color-mix(in srgb, var(--heading) 18%, transparent) transparent;
}

.tile-tab-btn {
    display: flex;
    align-items: center;
    flex: 0 0 214px;
    gap: 12px;
    padding: 16px 14px;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    background: var(--surface);
    color: var(--text);
    text-align: left;
    cursor: pointer;
    transition: all 0.25s ease;
}

.tile-tab-icon {
    width: 42px;
    height: 42px;
    object-fit: cover;
    border-radius: var(--radius-md);
    border: 1px solid var(--line);
    background: #fff;
    flex-shrink: 0;
}

.tile-tab-copy {
    display: grid;
    gap: 4px;
    min-width: 0;
}

.tile-tab-btn strong {
    font-size: 1rem;
    line-height: 1.2;
    color: var(--heading);
}

.tile-tab-btn span {
    font-size: 13px;
    color: var(--text-muted);
}

.tile-tab-btn:hover {
    border-color: var(--accent);
    transform: translateY(-2px);
}

.tile-tab-btn.is-active {
    border-color: transparent;
    background: linear-gradient(135deg, var(--accent), var(--accent-strong));
    box-shadow: 0 14px 28px rgba(17, 24, 39, 0.18);
}

.tile-tab-btn.is-active strong,
.tile-tab-btn.is-active span {
    color: #fff;
}

.tile-tab-btn.is-active .tile-tab-icon {
    border-color: rgba(255, 255, 255, 0.22);
    background: rgba(255, 255, 255, 0.08);
}

.tile-tab-more {
    flex-basis: 36px;
    justify-content: center;
    min-width: 0;
    padding: 16px 0;
}

.tile-tabs-nav::-webkit-scrollbar {
    height: 6px;
}

.tile-tabs-nav::-webkit-scrollbar-track {
    background: transparent;
}

.tile-tabs-nav::-webkit-scrollbar-thumb {
    border-radius: 999px;
    background: color-mix(in srgb, var(--heading) 16%, transparent);
}

.tile-tab-more-mark {
    font-size: 1.3rem;
    line-height: 1;
    letter-spacing: 0.08em;
    color: var(--text-muted);
}

.tile-tab-more:hover .tile-tab-more-mark {
    color: var(--heading);
}

.tile-tabs-shell .tab-panel {
    border: 1px solid var(--line);
    border-radius: calc(var(--radius-xl) + 2px);
    background: var(--surface);
    box-shadow: var(--shadow-soft);
    padding: 24px;
}

.tile-panel-grid {
    display: grid;
    grid-template-columns: minmax(320px, 0.95fr) minmax(0, 1.05fr);
    gap: 22px;
    align-items: start;
}

.tile-panel-copy {
    display: grid;
    gap: 16px;
}

.tile-panel-head {
    display: flex;
    align-items: center;
    gap: 14px;
}

.tile-panel-logo {
    width: 56px;
    height: 56px;
    object-fit: cover;
    border-radius: var(--radius-md);
    border: 1px solid var(--line);
    flex-shrink: 0;
    display: block;
}

.tile-panel-copy h3 {
    font-family: var(--font-display);
    font-size: clamp(1.6rem, 2vw, 2rem);
    line-height: 1.08;
    letter-spacing: -0.04em;
    color: var(--heading);
}

.tile-panel-list {
    list-style: none;
    display: grid;
    gap: 10px;
}

.tile-panel-list li {
    padding: 12px 14px;
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    background: var(--surface-strong);
    color: var(--text-muted);
}

.tile-panel-visual {
    padding: 0;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    background: var(--surface-strong);
    overflow: hidden;
}

.tile-panel-visual img {
    width: 100%;
    height: auto;
    display: block;
    border-radius: inherit;
    box-shadow: var(--shadow-soft);
}

.tile-panel-visual-chat {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100%;
    background: var(--surface);
}

.tile-panel-visual-chat img {
    width: auto;
    max-width: min(100%, 340px);
    max-height: 440px;
    margin: 0 auto;
}

@keyframes lift-in {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 1180px) {
    .header-shell {
        align-items: flex-start;
    }

    .header-left,
    .header-right {
        flex-direction: column;
        align-items: flex-start;
    }

    .brand-mark {
        border-right: 0;
        padding-right: 0;
    }
}

@media (max-width: 980px) {
    section {
        padding: 88px 0;
    }

    .site-header {
        position: static;
    }

    .hero {
        min-height: auto;
        padding: 30px 0 72px;
    }

    .hero-grid,
    .stack-frame-box,
    .stack-frame-box.is-reverse,
    .signal-board,
    .tile-panel-grid {
        grid-template-columns: 1fr;
    }

    .hero-layout {
        gap: 24px;
    }

    .tile-tab-btn {
        flex-basis: 204px;
    }
}

@media (max-width: 720px) {
    .container,
    .footer-content,
    .header-shell,
    .hero-shell,
    .tile-tabs-shell {
        width: min(var(--content-max), calc(100% - 24px));
    }

    section {
        padding: 72px 0;
    }

    .header-shell {
        padding: 16px 20px;
    }

    .header-nav {
        gap: 6px;
    }

    .header-nav a,
    .language-toggle {
        min-height: 40px;
    }

    .hero h1 {
        font-size: clamp(2.35rem, 11vw, 3.5rem);
        white-space: normal;
    }

    .tagline-lined::before,
    .tagline-lined::after {
        content: "";
        display: none;
    }

    .section-title,
    .stats-header {
        margin-bottom: 42px;
    }

    .section-title h2,
    .form-container h2,
    .stats-header h3,
    .stack-frame-heading h3 {
        line-height: 1.08;
    }

    .buttons {
        flex-direction: column;
    }

    .btn,
    .submit-btn {
        width: 100%;
    }

    .stack-frame-box,
    .signal-card,
    .tile-tabs-shell .tab-panel,
    .footer-content,
    .form-container,
    .hero-visual-frame {
        padding: 18px;
    }

    .tile-tab-btn {
        flex-basis: 188px;
    }

    .tile-panel-head {
        align-items: flex-start;
    }

    .download-layout,
    .download-options {
        grid-template-columns: 1fr;
    }

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

    .footer-bottom {
        flex-direction: column;
        align-items: flex-start;
    }

    .footer-wechat-popover {
        right: auto;
        left: 0;
    }
}