:root {
    --canvas: #ffffff;
    --surface: #ffffff;
    --ink: #111318;
    --muted: #5c6370;
    --line: rgba(28, 28, 30, 0.1);
    --accent: #153bff;
    --accent-deep: #0e2ad6;
    --accent-soft: #e8edff;
    --cyan: #5ad2ff;
    --highlight: #fff3a3;
    --radius: 1.4rem;
    --radius-sm: 0.9rem;
    --shadow: 0 12px 32px rgba(17, 19, 24, 0.08), 0 2px 8px rgba(17, 19, 24, 0.05);
    --nav-h: 4.5rem;
    --max: 70rem;
    --font: "Inter", "Segoe UI", system-ui, sans-serif;
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    background: var(--canvas);
    color: var(--ink);
    font-family: var(--font);
    font-size: 1.0625rem;
    line-height: 1.55;
}

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

a {
    color: inherit;
}

.skip {
    position: absolute;
    left: 0.75rem;
    top: -3rem;
    z-index: 80;
    background: var(--ink);
    color: #fff;
    padding: 0.5rem 0.85rem;
    border-radius: 999px;
}

.skip:focus {
    top: 0.75rem;
}

.wrap {
    width: min(calc(100% - 2rem), var(--max));
    margin-inline: auto;
}

.nav {
    position: sticky;
    top: 0;
    z-index: 40;
    height: var(--nav-h);
    display: flex;
    align-items: center;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--line);
}

.nav__inner {
    width: min(calc(100% - 2rem), var(--max));
    margin-inline: auto;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 0.55rem;
    text-decoration: none;
    font-weight: 800;
    letter-spacing: -0.04em;
    font-size: 1.15rem;
}

.brand img {
    width: 1.7rem;
    height: 1.7rem;
}

.nav__links {
    display: flex;
    align-items: center;
    gap: 1.15rem;
    margin: 0;
    list-style: none;
    padding: 0;
}

.nav__links a {
    text-decoration: none;
    color: var(--muted);
    font-size: 0.95rem;
    font-weight: 600;
}

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

.nav__panel {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    margin-left: auto;
}

.nav__actions {
    display: flex;
    align-items: center;
    gap: 0.55rem;
    margin-left: 0.4rem;
}

.nav__actions .btn {
    min-height: 2.5rem;
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
    line-height: 1.2;
}

.lang-switch {
    color: var(--muted);
    font-size: 0.9rem;
    font-weight: 600;
    text-decoration: none;
    white-space: nowrap;
}

.lang-switch:hover {
    color: var(--ink);
}

html[lang="zh-Hant"] {
    --font: "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", sans-serif;
}

html[lang="zh-Hant"] body {
    line-height: 1.7;
}

html[lang="zh-Hant"] h1,
html[lang="zh-Hant"] h2,
html[lang="zh-Hant"] h3 {
    letter-spacing: -0.02em;
    line-height: 1.28;
}

html[lang="zh-Hant"] .hero h1 {
    font-size: clamp(2.15rem, 5vw, 3.35rem);
    line-height: 1.22;
    letter-spacing: -0.03em;
}

html[lang="zh-Hant"] .kicker,
html[lang="zh-Hant"] .footer h3 {
    letter-spacing: 0.12em;
}

.btn--on-dark {
    background: transparent;
    border-color: rgba(255, 255, 255, 0.28);
    color: #fff;
}

.nav-toggle {
    display: none;
    margin-left: auto;
    border: 1px solid var(--line);
    background: var(--surface);
    border-radius: 0.7rem;
    width: 2.75rem;
    height: 2.75rem;
    cursor: pointer;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
    text-decoration: none;
    border-radius: 999px;
    padding: 0.72rem 1.15rem;
    font-weight: 700;
    font-size: 0.95rem;
    border: 1.5px solid transparent;
    cursor: pointer;
    font-family: inherit;
}

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

.btn--primary:hover {
    background: var(--accent-deep);
}

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

.btn--ghost:hover {
    border-color: rgba(21, 59, 255, 0.35);
}

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

.hero {
    padding: 3.5rem 0 2.5rem;
}

.pill {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    border-radius: 999px;
    padding: 0.35rem 0.75rem;
    background: var(--accent-soft);
    color: var(--accent);
    font-size: 0.82rem;
    font-weight: 700;
}

.pill__dot {
    width: 0.45rem;
    height: 0.45rem;
    border-radius: 50%;
    background: var(--accent);
}

.hero__copy {
    max-width: 42rem;
    margin-inline: auto;
    text-align: center;
}

.hero h1 {
    margin: 1rem 0 0.8rem;
    font-size: clamp(2.3rem, 5.4vw, 3.7rem);
    line-height: 1.08;
    letter-spacing: -0.045em;
    text-wrap: balance;
}

.mark {
    background: linear-gradient(180deg, transparent 62%, var(--highlight) 62%);
}

.hero p.lede {
    margin: 0 auto 1.4rem;
    color: var(--muted);
    font-size: 1.12rem;
    max-width: 36rem;
}

.hero .cta-row,
.hero .trust-strip {
    justify-content: center;
}

[hidden] {
    display: none !important;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.cta-row {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.7rem;
}

.trust-strip {
    display: flex;
    flex-wrap: wrap;
    gap: 0.85rem 1.4rem;
    margin-top: 1.35rem;
    color: var(--muted);
    font-size: 0.9rem;
    font-weight: 600;
}

.trust-strip span {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
}

.hero-preview {
    margin: 2.4rem 0 0;
}

.browser {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 1.2rem;
    box-shadow: var(--shadow);
    overflow: hidden;
}

.browser__bar {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.7rem 0.9rem;
    border-bottom: 1px solid var(--line);
    background: #f3f4f7;
}

.browser__dots {
    display: flex;
    gap: 0.35rem;
}

.browser__dots i {
    width: 0.55rem;
    height: 0.55rem;
    border-radius: 50%;
    background: #d5d7de;
    display: block;
}

.browser__url {
    flex: 1;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 999px;
    padding: 0.28rem 0.8rem;
    color: var(--muted);
    font-size: 0.78rem;
}

.sample {
    position: relative;
    padding: 1.5rem 1.4rem 5.5rem;
    min-height: 18rem;
}

.sample h2 {
    margin: 0 0 0.7rem;
    font-size: 1.2rem;
    letter-spacing: -0.03em;
}

.sample p {
    margin: 0;
    color: #2b303b;
    max-width: 38rem;
}

.selected {
    background: rgba(21, 59, 255, 0.14);
    border-radius: 0.2rem;
    padding: 0 0.12rem;
    box-shadow: 0 0 0 2px rgba(21, 59, 255, 0.12);
}

.lookup-card {
    position: absolute;
    top: 7.1rem;
    left: 1.1rem;
    width: min(20.5rem, calc(100% - 2.2rem));
    background: #fff;
    border: 1px solid rgba(60, 60, 67, 0.12);
    border-radius: 0.7rem;
    box-shadow: 0 12px 30px rgba(15, 23, 42, 0.14);
    padding: 0.7rem 0.85rem 0.85rem;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    font-size: 0.9rem;
}

.lookup-card__arrow {
    position: absolute;
    top: -8px;
    left: 8.4rem;
    width: 0;
    height: 0;
    border-right: 8px solid transparent;
    border-bottom: 8px solid #fff;
    border-left: 8px solid transparent;
    filter: drop-shadow(0 -1px 1px rgba(15, 23, 42, 0.08));
}

.lookup-card__top {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 0.5rem;
}

.lookup-card__word {
    display: inline-flex;
    align-items: center;
    font-weight: 600;
    font-size: 1rem;
}

.lookup-card__speaker {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 1.25rem;
    height: 1.25rem;
    margin-left: 0.35rem;
    color: rgba(28, 28, 30, 0.38);
}

.lookup-card__speaker svg {
    width: 0.9rem;
    height: 0.9rem;
}

.lookup-card__brand {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    color: #1c1c1e;
    font-size: 0.72rem;
    font-weight: 700;
}

.lookup-card__brand img {
    width: 0.95rem;
    height: 0.95rem;
}

.pos {
    display: inline-flex;
    margin: 0.4rem 0 0.45rem;
    padding: 0.1rem 0.5rem;
    border-radius: 999px;
    background: rgba(28, 28, 30, 0.08);
    font-size: 0.75rem;
}

.ipa {
    color: var(--muted);
    font-size: 0.82rem;
    margin-bottom: 0.35rem;
}

.lookup-card__details {
    color: #4b5563;
    font-size: 0.82rem;
}

.section,
.hero,
#install {
    scroll-margin-top: calc(var(--nav-h) + 0.75rem);
}

.section {
    padding: 4.2rem 0;
}

.section--tint {
    background: #f7f7f9;
}

.section--ink {
    background: #11162a;
    color: #f4f6ff;
}

.kicker {
    margin: 0 0 0.55rem;
    color: var(--accent);
    font-size: 0.82rem;
    font-weight: 800;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.section--ink .kicker {
    color: var(--cyan);
}

.section h2 {
    margin: 0 0 0.7rem;
    font-size: clamp(1.7rem, 3.4vw, 2.4rem);
    letter-spacing: -0.04em;
    line-height: 1.15;
}

.section > .wrap > .sub,
.lead {
    margin: 0 0 2rem;
    color: var(--muted);
    max-width: 38rem;
}

.section--ink .lead {
    color: rgba(244, 246, 255, 0.72);
}

.context-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
}

.context-example {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: 0 8px 24px rgba(17, 19, 24, 0.04);
}

.context-pagebar {
    display: flex;
    align-items: center;
    gap: 0.65rem;
    min-height: 2.5rem;
    padding: 0.55rem 0.75rem;
    border-bottom: 1px solid rgba(60, 60, 67, 0.1);
    background: #f3f4f7;
    color: #8a909b;
    font: 500 0.7rem/1 -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.context-pagebar > span {
    display: flex;
    gap: 0.25rem;
}

.context-pagebar i {
    display: block;
    width: 0.42rem;
    height: 0.42rem;
    border-radius: 50%;
    background: #d5d7de;
}

.context-stage {
    position: relative;
    min-height: 10.75rem;
    padding: 1.45rem 1.25rem;
    background: #fff;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.context-sentence {
    margin: 0;
    color: #2b303b;
    font-size: 1rem;
    font-weight: 500;
    line-height: 1.55;
}

.context-sentence mark {
    background: #3478ff;
    color: #fff;
    padding: 0;
}

.product-brief {
    position: absolute;
    top: 5.15rem;
    z-index: 1;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    width: max-content;
    max-width: calc(100% - 2rem);
    color: #1c1c1e;
    font: 400 0.95rem/1.35 -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.product-brief--fee {
    left: 2.7rem;
    --brief-caret-left: 1.35rem;
}

.product-brief--battery {
    left: 1rem;
    --brief-caret-left: 0.7rem;
}

.product-brief--accuse {
    left: 4.1rem;
    --brief-caret-left: 1.4rem;
}

.product-brief__caret {
    width: 0;
    height: 0;
    margin: 0 0 -1px var(--brief-caret-left);
    border-right: 7px solid transparent;
    border-bottom: 7px solid #fff;
    border-left: 7px solid transparent;
    filter: drop-shadow(0 -1px 1px rgba(15, 23, 42, 0.08));
}

.product-brief__card {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    max-width: 100%;
    margin: 0;
    padding: 6px 10px 5px;
    border: 1px solid rgba(60, 60, 67, 0.12);
    border-radius: 8px;
    background: #fff;
    box-shadow: 0 8px 24px rgba(15, 23, 42, 0.14);
}

.product-brief__meaning {
    min-width: 0;
    color: #1c1c1e;
    font-weight: 500;
    text-align: left;
}

.product-brief__detail {
    align-self: flex-end;
    min-height: 14px;
    color: #9ca3af;
    font-size: 10px;
    font-weight: 500;
    line-height: 1.2;
}

.features {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
}

.feature {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 1.15rem;
}

.feature h3 {
    margin: 0 0 0.45rem;
    font-size: 1.2rem;
    letter-spacing: -0.03em;
}

.feature p {
    margin: 0;
    color: var(--muted);
}

.feature__visual {
    min-height: 8.2rem;
    border-radius: 1rem;
    background: linear-gradient(160deg, #f4f6ff, #e8edff);
    border: 1px solid rgba(21, 59, 255, 0.08);
    padding: 0.85rem;
}

.mini-card,
.mini-steps,
.mini-phrase {
    background: #fff;
    border-radius: 0.8rem;
    border: 1px solid var(--line);
    padding: 0.85rem 1rem;
}

.mini-card strong {
    display: block;
    margin-bottom: 0.25rem;
}

.mini-card span {
    color: var(--muted);
    font-size: 0.88rem;
}

.mini-phrase {
    display: grid;
    grid-template-columns: auto 1fr;
    align-items: baseline;
    gap: 0.15rem 0.35rem;
}

.mini-phrase span {
    color: var(--muted);
}

.mini-phrase strong {
    color: var(--accent);
}

.mini-phrase small {
    grid-column: 1 / -1;
    margin-top: 0.3rem;
    color: var(--muted);
}

.mini-steps ol {
    margin: 0;
    padding-left: 1.1rem;
    color: var(--muted);
}

.steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
}

.step {
    background: var(--surface);
    border-radius: var(--radius);
    border: 1px solid var(--line);
    padding: 1.3rem;
}

.step__n {
    width: 2rem;
    height: 2rem;
    border-radius: 999px;
    background: var(--accent);
    color: #fff;
    display: grid;
    place-items: center;
    font-weight: 800;
    margin-bottom: 0.8rem;
}

.step h3 {
    margin: 0 0 0.4rem;
}

.step p {
    margin: 0;
    color: var(--muted);
}

.faq details {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 1rem;
    padding: 0.95rem 1.1rem;
    margin-bottom: 0.65rem;
}

.faq summary {
    cursor: pointer;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.faq details p {
    margin: 0.7rem 0 0;
    color: var(--muted);
}

.final {
    text-align: center;
}

.final h2 {
    max-width: 22ch;
    margin-inline: auto;
}

.final .lead {
    margin-inline: auto;
}

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

.footer {
    padding: 2.6rem 0 2rem;
    border-top: 1px solid var(--line);
    color: var(--muted);
    font-size: 0.92rem;
}

.footer__grid {
    display: grid;
    grid-template-columns: 1.6fr 1fr 1fr;
    gap: 1.4rem;
}

.footer h3 {
    margin: 0 0 0.6rem;
    color: var(--ink);
    font-size: 0.82rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.footer ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.footer a {
    text-decoration: none;
}

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

.legal {
    padding: 3rem 0 4rem;
}

.legal .wrap {
    max-width: 48rem;
}

.legal__updated {
    color: var(--muted);
    font-size: 0.95rem;
}

.legal h1 {
    margin-top: 0;
    letter-spacing: -0.04em;
}

.legal h2 {
    margin-top: 1.8rem;
    font-size: 1.15rem;
}

.placeholder {
    font-style: italic;
    color: #8a909b;
}

@media (max-width: 880px) {
    .nav-toggle {
        display: inline-flex;
        align-items: center;
        justify-content: center;
    }

    .nav__panel {
        display: none;
        position: absolute;
        left: 0;
        right: 0;
        top: var(--nav-h);
        margin: 0;
        flex-direction: column;
        align-items: flex-start;
        gap: 0.85rem;
        background: #fff;
        border-bottom: 1px solid var(--line);
        padding: 0.9rem 1rem 1.1rem;
    }

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

    .nav__links,
    .nav__actions {
        margin-left: 0;
        flex-direction: column;
        align-items: flex-start;
        gap: 0.25rem;
        width: 100%;
    }

    .nav__links li {
        width: 100%;
    }

    .nav__links a,
    .lang-switch {
        display: flex;
        align-items: center;
        min-height: 2.75rem;
        width: 100%;
        padding: 0.5rem 0.25rem;
    }

    .nav__actions .btn {
        min-height: 2.75rem;
        width: 100%;
    }

    .context-grid,
    .features,
    .steps,
    .footer__grid {
        grid-template-columns: 1fr;
    }

    .hero,
    .section {
        padding-top: 2.4rem;
        padding-bottom: 2.4rem;
    }
}

@media (max-width: 420px) {
    html[lang="zh-Hant"] .hero h1 {
        font-size: 2rem;
    }
}

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