:root {
    --ext-bg: #f6f8fc;
    --ext-surface: #ffffff;
    --ext-surface-soft: #eef3ff;
    --ext-text: #14213d;
    --ext-muted: #63708a;
    --ext-border: #dfe5ef;
    --ext-primary: #246bfd;
    --ext-primary-dark: #174fc5;
    --ext-accent: #16a085;
    --ext-dark: #101827;
    --ext-shadow: 0 24px 70px rgba(24, 44, 88, .12);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
    margin: 0;
    background: var(--ext-bg);
    color: var(--ext-text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", Arial, sans-serif;
    -webkit-font-smoothing: antialiased;
}

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

button, a { -webkit-tap-highlight-color: transparent; }

.extension-container {
    width: min(1180px, calc(100% - 40px));
    margin: 0 auto;
}

.extension-site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    border-bottom: 1px solid rgba(223, 229, 239, .9);
    background: rgba(255, 255, 255, .94);
    backdrop-filter: blur(16px);
}

.extension-site-header-inner {
    display: flex;
    align-items: center;
    min-height: 72px;
    gap: 28px;
}

.extension-brand {
    display: inline-flex;
    align-items: center;
    gap: 11px;
    flex: 0 0 auto;
}

.extension-brand img {
    display: block;
    border-radius: 10px;
    box-shadow: 0 7px 18px rgba(36, 107, 253, .22);
}

.extension-brand span {
    display: grid;
    line-height: 1.15;
}

.extension-brand strong { font-size: 15px; }

.extension-brand small {
    margin-top: 4px;
    color: var(--ext-muted);
    font-size: 11px;
}

.extension-site-nav {
    display: flex;
    align-items: center;
    gap: 24px;
    margin: 0 auto;
    color: var(--ext-muted);
    font-size: 14px;
}

.extension-site-nav a {
    position: relative;
    padding: 26px 0;
    transition: color .2s ease;
}

.extension-site-nav a:hover,
.extension-site-nav a.is-active { color: var(--ext-text); }

.extension-site-nav a.is-active::after {
    position: absolute;
    right: 0;
    bottom: 16px;
    left: 0;
    height: 2px;
    border-radius: 2px;
    background: var(--ext-primary);
    content: "";
}

.extension-header-actions {
    display: flex;
    align-items: center;
    gap: 8px;
    flex: 0 0 auto;
}

.extension-theme-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 36px;
    gap: 6px;
    padding: 0 12px;
    border: 1px solid var(--ext-border);
    border-radius: 9px;
    background: var(--ext-surface);
    color: var(--ext-text);
    font: inherit;
    font-size: 13px;
    cursor: pointer;
}

.extension-theme-toggle:hover { border-color: #a9b7ce; }

.portal-theme-toggle-icon { font-size: 16px; }

.extension-hero {
    position: relative;
    overflow: hidden;
    border-bottom: 1px solid var(--ext-border);
    background: #f1f5ff;
}

.extension-hero::before,
.extension-hero::after {
    position: absolute;
    border: 1px solid rgba(36, 107, 253, .12);
    border-radius: 50%;
    content: "";
    pointer-events: none;
}

.extension-hero::before {
    width: 540px;
    height: 540px;
    top: -330px;
    left: -180px;
}

.extension-hero::after {
    width: 360px;
    height: 360px;
    right: -190px;
    bottom: -250px;
}

.extension-hero-grid {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: minmax(0, 1fr) 440px;
    align-items: center;
    min-height: 720px;
    gap: 70px;
    padding-top: 68px;
    padding-bottom: 68px;
}

.extension-eyebrow,
.extension-section-head > span,
.extension-assurance-kicker {
    display: block;
    margin-bottom: 18px;
    color: var(--ext-primary);
    font-size: 12px;
    font-weight: 800;
    letter-spacing: .16em;
    text-transform: uppercase;
}

.extension-hero-copy h1 {
    max-width: 700px;
    margin: 0;
    font-size: clamp(42px, 5vw, 68px);
    line-height: 1.08;
    letter-spacing: -.045em;
}

.extension-hero-copy > p {
    max-width: 650px;
    margin: 26px 0 0;
    color: var(--ext-muted);
    font-size: 18px;
    line-height: 1.85;
}

.extension-hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 34px;
}

.extension-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 50px;
    gap: 9px;
    padding: 0 22px;
    border: 1px solid transparent;
    border-radius: 10px;
    font-size: 15px;
    font-weight: 700;
    transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
}

.extension-button:hover { transform: translateY(-2px); }

.extension-button-primary {
    background: var(--ext-primary);
    color: #fff;
    box-shadow: 0 14px 28px rgba(36, 107, 253, .24);
}

.extension-button-primary:hover { background: var(--ext-primary-dark); }

.extension-button-secondary {
    border-color: var(--ext-border);
    background: var(--ext-surface);
    color: var(--ext-text);
}

.extension-button-secondary:hover { border-color: #b6c1d3; }

.extension-trust-list {
    display: flex;
    flex-wrap: wrap;
    gap: 10px 20px;
    margin: 28px 0 0;
    padding: 0;
    color: var(--ext-muted);
    font-size: 13px;
    list-style: none;
}

.extension-trust-list li { display: inline-flex; align-items: center; gap: 6px; }
.extension-trust-list li span { color: var(--ext-accent); font-weight: 800; }

.extension-preview {
    position: relative;
    width: 100%;
    overflow: hidden;
    border: 1px solid #d9e2f1;
    border-radius: 22px;
    background: #e9eef8;
    box-shadow: var(--ext-shadow);
    transform: rotate(1.3deg);
}

.extension-preview-toolbar {
    display: flex;
    align-items: center;
    height: 46px;
    gap: 7px;
    padding: 0 14px;
    border-bottom: 1px solid #d8e0ec;
    background: #f8fafc;
}

.extension-preview-toolbar > span {
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: #c5cedd;
}

.extension-preview-toolbar > span:first-child { background: #ff6b61; }
.extension-preview-toolbar > span:nth-child(2) { background: #f4b740; }
.extension-preview-toolbar > span:nth-child(3) { background: #35bd72; }

.extension-preview-toolbar div {
    flex: 1;
    margin-left: 8px;
    padding: 6px 11px;
    border-radius: 7px;
    background: #eef2f7;
    color: #9aa6b8;
    font-size: 11px;
}

.extension-preview-body {
    height: 514px;
    overflow: hidden;
    background: #fff;
}

.extension-preview-body img {
    display: block;
    width: 100%;
    height: auto;
}

.extension-version-badge {
    position: absolute;
    right: 16px;
    bottom: 16px;
    padding: 7px 10px;
    border: 1px solid rgba(255, 255, 255, .5);
    border-radius: 8px;
    background: rgba(16, 24, 39, .88);
    color: #fff;
    font-size: 12px;
    font-weight: 800;
    letter-spacing: .06em;
}

.extension-section { padding: 94px 0; }

.extension-section-head {
    max-width: 720px;
    margin: 0 auto 44px;
    text-align: center;
}

.extension-section-head h2,
.extension-assurance-grid h2,
.extension-final-cta h2 {
    margin: 0;
    font-size: clamp(30px, 3.5vw, 46px);
    line-height: 1.18;
    letter-spacing: -.025em;
}

.extension-section-head p {
    margin: 16px 0 0;
    color: var(--ext-muted);
    font-size: 16px;
    line-height: 1.8;
}

.extension-section-head-left { margin-right: 0; margin-left: 0; text-align: left; }

.extension-feature-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
}

.extension-feature-card {
    min-height: 250px;
    padding: 30px;
    border: 1px solid var(--ext-border);
    border-radius: 18px;
    background: var(--ext-surface);
    box-shadow: 0 12px 35px rgba(29, 48, 86, .05);
}

.extension-feature-card-wide { grid-column: span 2; }

.extension-feature-card-dark {
    border-color: var(--ext-dark);
    background: var(--ext-dark);
    color: #fff;
}

.extension-feature-icon {
    display: grid;
    place-items: center;
    width: 42px;
    height: 42px;
    margin-bottom: 48px;
    border: 1px solid #d5e1fb;
    border-radius: 11px;
    background: var(--ext-surface-soft);
    color: var(--ext-primary);
    font-size: 19px;
    font-weight: 800;
}

.extension-feature-card-dark .extension-feature-icon {
    border-color: #34425a;
    background: #1c2940;
    color: #83a9ff;
}

.extension-feature-card h3 { margin: 0 0 12px; font-size: 20px; }

.extension-feature-card p {
    margin: 0;
    color: var(--ext-muted);
    line-height: 1.75;
}

.extension-feature-card-dark p { color: #b6c2d8; }

.extension-install-section {
    border-top: 1px solid var(--ext-border);
    border-bottom: 1px solid var(--ext-border);
    background: var(--ext-surface);
}

.extension-install-grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 420px;
    align-items: center;
    gap: 90px;
}

.extension-steps {
    display: grid;
    gap: 0;
    margin: 34px 0 0;
    padding: 0;
    list-style: none;
}

.extension-steps li {
    display: grid;
    grid-template-columns: 52px minmax(0, 1fr);
    gap: 16px;
    padding: 20px 0;
    border-top: 1px solid var(--ext-border);
}

.extension-steps li:last-child { border-bottom: 1px solid var(--ext-border); }

.extension-steps b {
    color: var(--ext-primary);
    font-size: 13px;
    letter-spacing: .08em;
}

.extension-steps li div { display: grid; gap: 6px; }
.extension-steps strong { font-size: 16px; }
.extension-steps span { color: var(--ext-muted); line-height: 1.65; }

.extension-text-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin-top: 26px;
    color: var(--ext-primary);
    font-weight: 700;
}

.extension-login-preview { margin: 0; }

.extension-login-preview-frame {
    height: 510px;
    overflow: hidden;
    border: 1px solid var(--ext-border);
    border-radius: 20px;
    background: #f4f7fb;
    box-shadow: var(--ext-shadow);
}

.extension-login-preview img { display: block; width: 100%; height: auto; }

.extension-login-preview figcaption {
    margin-top: 16px;
    color: var(--ext-muted);
    font-size: 13px;
    line-height: 1.6;
    text-align: center;
}

.extension-browser-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
}

.extension-browser-grid article {
    padding: 28px;
    border: 1px solid var(--ext-border);
    border-radius: 16px;
    background: var(--ext-surface);
}

.extension-browser-grid h3 { margin: 22px 0 8px; font-size: 18px; }
.extension-browser-grid p { margin: 0; color: var(--ext-muted); line-height: 1.7; }

.extension-browser-mark {
    display: grid;
    place-items: center;
    width: 42px;
    height: 42px;
    border-radius: 50%;
    color: #fff;
    font-size: 22px;
    font-weight: 800;
}

.chrome-mark {
    border: 10px solid #36a852;
    background: #4285f4;
    box-shadow: inset 0 0 0 2px #fff, 10px 0 0 -5px #fbbc04, -7px -7px 0 -5px #ea4335;
}

.edge-mark { background: #0b79d0; }
.chromium-mark { background: #4054b2; }

.extension-compatibility-note {
    margin: 22px 0 0;
    color: var(--ext-muted);
    font-size: 13px;
    text-align: center;
}

.extension-assurance-section {
    border-top: 1px solid #233049;
    border-bottom: 1px solid #233049;
    background: var(--ext-dark);
    color: #fff;
}

.extension-assurance-grid {
    display: grid;
    grid-template-columns: .8fr 1.2fr;
    gap: 90px;
}

.extension-assurance-kicker { color: #82a9ff; }

.extension-assurance-copy p {
    margin: 0 0 22px;
    color: #c5cede;
    font-size: 17px;
    line-height: 1.85;
}

.extension-assurance-copy ul {
    display: grid;
    gap: 12px;
    margin: 0;
    padding: 0;
    color: #aebbd0;
    list-style: none;
}

.extension-assurance-copy li { position: relative; padding-left: 20px; line-height: 1.7; }
.extension-assurance-copy li::before { position: absolute; left: 0; color: #62d6bf; content: "✓"; }

.extension-faq-shell {
    display: grid;
    grid-template-columns: 340px minmax(0, 1fr);
    gap: 70px;
}

.extension-faq-list { border-top: 1px solid var(--ext-border); }

.extension-faq-list details { border-bottom: 1px solid var(--ext-border); }

.extension-faq-list summary {
    position: relative;
    padding: 24px 44px 24px 0;
    font-size: 17px;
    font-weight: 700;
    cursor: pointer;
    list-style: none;
}

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

.extension-faq-list summary::after {
    position: absolute;
    top: 22px;
    right: 5px;
    color: var(--ext-primary);
    font-size: 22px;
    content: "+";
}

.extension-faq-list details[open] summary::after { content: "−"; }

.extension-faq-list p {
    margin: -4px 0 24px;
    color: var(--ext-muted);
    line-height: 1.8;
}

.extension-final-cta { padding: 0 0 94px; }

.extension-final-cta-inner {
    display: grid;
    grid-template-columns: 56px minmax(0, 1fr) auto;
    align-items: center;
    gap: 24px;
    padding: 36px;
    border: 1px solid #cfdbf2;
    border-radius: 20px;
    background: #eaf1ff;
}

.extension-final-cta img { border-radius: 15px; box-shadow: 0 8px 20px rgba(36, 107, 253, .18); }
.extension-final-cta h2 { font-size: 26px; }
.extension-final-cta p { margin: 8px 0 0; color: var(--ext-muted); line-height: 1.7; }

.extension-footer {
    border-top: 1px solid var(--ext-border);
    background: var(--ext-surface);
}

.extension-footer .extension-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 86px;
    gap: 20px;
    color: var(--ext-muted);
    font-size: 13px;
}

.extension-footer nav { display: flex; gap: 20px; }
.extension-footer a:hover { color: var(--ext-primary); }

html.portal-dark {
    color-scheme: dark;
    --ext-bg: #091322;
    --ext-surface: #101c2e;
    --ext-surface-soft: #162846;
    --ext-text: #edf4ff;
    --ext-muted: #9aa9c0;
    --ext-border: #293b56;
    --ext-primary: #6d96ff;
    --ext-primary-dark: #4f7ff5;
    --ext-dark: #07101d;
    --ext-shadow: 0 24px 70px rgba(0, 0, 0, .35);
}

html.portal-dark .extension-site-header { background: rgba(10, 21, 36, .94); border-color: var(--ext-border); }
html.portal-dark .extension-hero { background: #0d1a2d; }
html.portal-dark .extension-preview { border-color: #33445f; background: #0a1423; }
html.portal-dark .extension-preview-toolbar { border-color: #33445f; background: #142238; }
html.portal-dark .extension-preview-toolbar div { background: #0c182a; color: #61728b; }
html.portal-dark .extension-theme-toggle,
html.portal-dark .extension-button-secondary { background: var(--ext-surface); color: var(--ext-text); }
html.portal-dark .extension-install-section { background: #0d192a; }
html.portal-dark .extension-final-cta-inner { border-color: #324a72; background: #122643; }
html.portal-dark .extension-footer { background: #08111f; }

@media (max-width: 1000px) {
    .extension-site-nav { display: none; }
    .extension-header-actions { margin-left: auto; }
    .extension-hero-grid { grid-template-columns: minmax(0, 1fr) 370px; gap: 36px; min-height: 660px; }
    .extension-install-grid { gap: 50px; }
}

@media (max-width: 780px) {
    .extension-container { width: min(calc(100% - 28px), 640px); }
    .extension-site-header-inner { min-height: 64px; gap: 10px; }
    .extension-brand small { display: none; }
    .extension-brand strong { font-size: 13px; }
    .extension-brand img { width: 32px; height: 32px; }
    .extension-theme-toggle { width: 36px; padding: 0; }
    .extension-theme-toggle .portal-theme-toggle-label { display: none; }
    .extension-hero-grid,
    .extension-install-grid,
    .extension-assurance-grid,
    .extension-faq-shell { grid-template-columns: 1fr; }
    .extension-hero-grid { min-height: 0; gap: 46px; padding-top: 54px; padding-bottom: 54px; }
    .extension-hero-copy { text-align: center; }
    .extension-hero-copy h1 { font-size: clamp(38px, 12vw, 54px); }
    .extension-hero-copy > p { font-size: 16px; }
    .extension-hero-actions,
    .extension-trust-list { justify-content: center; }
    .extension-preview { max-width: 430px; margin: 0 auto; transform: none; }
    .extension-preview-body { height: 480px; }
    .extension-section { padding: 70px 0; }
    .extension-feature-grid { grid-template-columns: 1fr; }
    .extension-feature-card-wide { grid-column: auto; }
    .extension-feature-card { min-height: 0; }
    .extension-feature-icon { margin-bottom: 34px; }
    .extension-install-grid { gap: 46px; }
    .extension-login-preview { width: min(100%, 430px); margin: 0 auto; }
    .extension-browser-grid { grid-template-columns: 1fr; }
    .extension-assurance-grid { gap: 34px; }
    .extension-faq-shell { gap: 10px; }
    .extension-final-cta-inner { grid-template-columns: 48px minmax(0, 1fr); padding: 26px; }
    .extension-final-cta img { width: 48px; height: 48px; }
    .extension-final-cta .extension-button { grid-column: 1 / -1; }
}

@media (max-width: 520px) {
    .extension-brand span { display: none; }
    .extension-header-actions { gap: 5px; }
    .extension-header-actions .portal-language-trigger { min-width: 36px; padding: 0 8px; }
    .extension-header-actions .portal-language-label { display: none; }
    .extension-eyebrow { font-size: 11px; letter-spacing: .11em; }
    .extension-hero-copy h1 { font-size: 38px; }
    .extension-button { width: 100%; }
    .extension-trust-list { display: grid; justify-content: start; text-align: left; }
    .extension-preview-body { height: 390px; }
    .extension-section-head h2,
    .extension-assurance-grid h2 { font-size: 31px; }
    .extension-feature-card { padding: 24px; }
    .extension-login-preview-frame { height: 420px; }
    .extension-final-cta-inner { display: flex; flex-direction: column; align-items: flex-start; }
    .extension-footer .extension-container { align-items: flex-start; flex-direction: column; justify-content: center; padding: 22px 0; }
    .extension-footer nav { flex-wrap: wrap; gap: 12px 18px; }
}

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after { transition-duration: .01ms !important; }
}