:root {
    --ink: #17191a;
    --muted: #5f666c;
    --paper: #f6f7f5;
    --surface: #ffffff;
    --line: #dfe3e1;
    --teal: #0d7a6c;
    --teal-dark: #0a5f55;
    --orange: #d96a2b;
    --red: #cf3f3f;
    --amber: #d89a17;
    --copper: #c9743a;
    --copper-dark: #a95c2b;
    --hero: #1a2d4f;
    --hero-muted: #c2d2e8;
    --radius: 8px;
    --shadow: 0 18px 50px rgba(17, 24, 22, 0.08);
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

#top {
    scroll-margin-top: 76px;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
    color: var(--ink);
    background: var(--paper);
    line-height: 1.65;
    letter-spacing: 0;
}

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

img {
    display: block;
}

code {
    padding: 2px 6px;
    border-radius: 5px;
    background: rgba(13, 122, 108, 0.1);
    color: var(--teal-dark);
    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
    font-size: 0.9em;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    padding: 12px 28px;
    color: #fff;
    background: rgba(26, 45, 79, 0.95);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    font-size: 17px;
}

.brand-mark {
    width: 30px;
    height: 30px;
    border-radius: 7px;
}

.site-nav {
    display: flex;
    align-items: center;
    gap: 22px;
    font-size: 14px;
    font-weight: 600;
    color: #c2d2e8;
}

.site-nav a:hover {
    color: #fff;
}

.site-nav a {
    flex: 0 0 auto;
    white-space: nowrap;
}

.account-trigger {
    flex: 0 0 auto;
    font-size: 14px;
    font-weight: 600;
    color: #c2d2e8;
    white-space: nowrap;
    text-decoration: none;
}

.account-trigger:hover {
    color: #fff;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-left: auto;
}

.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 42px;
    padding: 0 18px;
    border-radius: var(--radius);
    font-size: 14px;
    font-weight: 700;
    white-space: nowrap;
}

.lang-toggle {
    display: inline-flex;
    align-items: center;
    gap: 2px;
    min-height: 38px;
    padding: 3px;
    border: 1px solid rgba(255, 255, 255, 0.28);
    border-radius: var(--radius);
    background: rgba(255, 255, 255, 0.06);
    cursor: pointer;
}

.lang-toggle:hover {
    background: rgba(255, 255, 255, 0.12);
}

.lang-option {
    padding: 5px 9px;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 700;
    color: rgba(255, 255, 255, 0.72);
}

.lang-option.active {
    color: #10201b;
    background: #e4b184;
}

.lang-sep {
    width: 1px;
    height: 16px;
    background: rgba(255, 255, 255, 0.22);
}

.hero {
    min-height: 78vh;
    display: grid;
    grid-template-columns: minmax(0, 1.25fr) minmax(280px, 0.75fr);
    align-items: center;
    gap: 48px;
    max-width: 1320px;
    margin: 24px auto 0;
    padding: 72px 28px;
    color: #fff;
    background: linear-gradient(135deg, #193769 0%, #1e4a7a 50%, #245a8a 100%);
    border-radius: 24px;
    overflow: hidden;
}

.eyebrow {
    margin: 0 0 10px;
    font-size: 12px;
    font-weight: 800;
    letter-spacing: 1.4px;
    color: var(--teal);
    text-transform: uppercase;
}

.hero .eyebrow {
    color: #e4b184;
}

.hero h1 {
    margin: 0;
    font-size: 72px;
    line-height: 1.02;
    letter-spacing: 0;
}

.hero-lead {
    max-width: 640px;
    margin: 22px 0 0;
    font-size: 18px;
    color: #e0e9f0;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 32px;
}

.button-primary {
    color: #fff;
    background: #e08a4a;
}

.button-primary:hover {
    background: #c9753a;
}

.button-ghost {
    color: #fff;
    border: 1px solid rgba(255, 255, 255, 0.34);
}

.button-ghost:hover {
    border-color: #fff;
}

.hero-visual {
    position: relative;
    display: grid;
    place-items: center;
    min-height: 360px;
}

.hero-app-icon {
    position: relative;
    z-index: 2;
    width: min(62%, 264px);
    border-radius: 22px;
}

.hero-ring {
    position: absolute;
    width: min(70%, 310px);
    aspect-ratio: 1;
    border: 3px solid rgba(255, 255, 255, 0.24);
    border-radius: 50%;
    transform-origin: center;
    animation: hero-ripple 3.4s ease-out infinite;
}

.hero-ring::before,
.hero-ring::after {
    content: "";
    position: absolute;
    inset: 9%;
    border: 3px solid rgba(255, 255, 255, 0.14);
    border-radius: 50%;
    transform-origin: center;
    animation: hero-ripple 3.4s ease-out infinite;
}

.hero-ring::after {
    inset: 19%;
}

.hero-ring::before {
    animation-delay: 1.1s;
}

.hero-ring::after {
    animation-delay: 2.2s;
}

@keyframes hero-ripple {
    0% {
        transform: scale(0.55);
        opacity: 0.6;
    }
    75% {
        opacity: 0.22;
    }
    100% {
        transform: scale(2.2);
        opacity: 0;
    }
}

@media (min-width: 1161px) {
    .hero {
        padding-left: 108px;
    }
}

.stats {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    max-width: 1160px;
    margin: -34px auto 0;
    padding: 0 28px;
}

.stat {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 112px;
    border-right: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
    background: var(--surface);
}

.stat:first-child {
    border-radius: 8px 0 0 8px;
    border-left: 1px solid var(--line);
}

.stat:last-child {
    border-radius: 0 8px 8px 0;
}

.stat strong {
    font-size: 26px;
    line-height: 1.1;
    color: var(--teal-dark);
}

.stat span {
    margin-top: 6px;
    font-size: 12px;
    color: var(--muted);
}

.section {
    max-width: 1160px;
    margin: 0 auto;
    padding: 96px 28px 72px;
}

.section-alt {
    max-width: none;
    margin: 0;
    padding-left: max(28px, calc((100vw - 1160px) / 2));
    padding-right: max(28px, calc((100vw - 1160px) / 2));
    background: var(--surface);
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
}

.about-hero {
    max-width: 1320px;
    margin: 24px auto 0;
    padding: 64px 28px;
    color: #fff;
    background-color: #4f7189;
    border-radius: 24px;
}

.about-hero h1 {
    margin: 0;
    font-size: 56px;
    line-height: 1.08;
}

.about-hero .hero-lead {
    margin-top: 18px;
}

.about-body {
    max-width: 920px;
    margin: 0;
    font-size: 16px;
    color: var(--muted);
}

.contact-card {
    display: flex;
    align-items: center;
    gap: 16px;
    max-width: 520px;
    padding: 20px;
    color: var(--ink);
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.contact-card:hover {
    border-color: var(--copper);
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.contact-info strong {
    font-size: 14px;
    color: var(--muted);
}

.contact-info span {
    font-size: 16px;
    font-weight: 700;
    color: var(--teal-dark);
}

.section-heading {
    max-width: 720px;
    margin-bottom: 38px;
}

.section-heading h2 {
    margin: 0;
    font-size: 34px;
    line-height: 1.16;
    letter-spacing: 0;
}

.section-heading p:last-child {
    margin: 14px 0 0;
    font-size: 16px;
    color: var(--muted);
}

.grid {
    display: grid;
    gap: 18px;
}

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

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

.grid-three {
    grid-template-columns: repeat(3, 1fr);
}

.feature-card,
.view-card,
.tool-item {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.feature-card {
    padding: 22px;
    border-top: 3px solid var(--teal);
}

.feature-noise {
    border-top-color: var(--red);
}

.feature-vibration {
    border-top-color: var(--amber);
}

.feature-signal {
    border-top-color: var(--teal);
}

.feature-post {
    border-top-color: var(--copper);
}

.card-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 18px;
}

.card-index {
    font-size: 12px;
    font-weight: 800;
    color: var(--muted);
}

.card-icon {
    display: grid;
    place-items: center;
    width: 44px;
    height: 44px;
    border-radius: 8px;
    color: var(--teal-dark);
    background: rgba(13, 122, 108, 0.1);
}

.feature-noise .card-icon {
    color: var(--red);
    background: rgba(207, 63, 63, 0.1);
}

.feature-vibration .card-icon {
    color: var(--amber);
    background: rgba(216, 154, 23, 0.12);
}

.feature-signal .card-icon {
    color: var(--teal-dark);
    background: rgba(13, 122, 108, 0.1);
}

.feature-post .card-icon {
    color: var(--copper);
    background: rgba(201, 116, 58, 0.12);
}

.card-icon svg {
    width: 22px;
    height: 22px;
}

.feature-card h3,
.view-card h3,
.tool-item h3 {
    margin: 0;
    font-size: 17px;
    line-height: 1.3;
}

.feature-card p,
.view-card p,
.tool-item p {
    margin: 10px 0 0;
    font-size: 14px;
    color: var(--muted);
}

.feature-card ul {
    margin: 12px 0 0;
    padding: 0;
    list-style: none;
}

.feature-card li {
    position: relative;
    padding-left: 18px;
    margin-top: 7px;
    font-size: 14px;
    color: var(--muted);
}

.feature-card li::before {
    content: "●";
    position: absolute;
    left: 2px;
    top: 0;
    font-size: 10px;
    color: var(--teal);
}

.view-card {
    padding: 20px 18px;
    border-top: 3px solid var(--teal);
}

.view-card:nth-child(2) {
    border-top-color: var(--orange);
}

.view-card:nth-child(3) {
    border-top-color: var(--red);
}

.view-card:nth-child(4) {
    border-top-color: var(--amber);
}

.view-card:nth-child(5) {
    border-top-color: var(--copper);
}

.view-card .card-icon {
    margin-bottom: 14px;
}

.tools-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.tool-item {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    padding: 18px;
}

.tools-layout .tool-item:last-child {
    grid-column: 1 / -1;
}

.screenshot-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 22px;
}

.shot {
    margin: 0;
}

.shot-frame {
    position: relative;
    aspect-ratio: 1206 / 2622;
    overflow: hidden;
    border-radius: var(--radius);
    background: var(--surface);
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}

.shot-placeholder {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 24px;
    text-align: center;
    background:
        linear-gradient(rgba(13, 122, 108, 0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(13, 122, 108, 0.05) 1px, transparent 1px),
        #f0f3f1;
    background-size: 26px 26px;
    border: 1px dashed rgba(13, 122, 108, 0.3);
}

.shot-frame img {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: var(--radius);
}

.shot-icon {
    display: grid;
    place-items: center;
    width: 52px;
    height: 52px;
    border-radius: 8px;
    color: var(--teal-dark);
    background: #fff;
    border: 1px solid var(--line);
}

.shot-icon svg {
    width: 28px;
    height: 28px;
}

.shot-title {
    font-weight: 800;
    color: var(--ink);
}

.shot-note {
    font-size: 12px;
    color: var(--muted);
}

.shot figcaption {
    margin-top: 10px;
    font-size: 13px;
    font-weight: 700;
    color: var(--muted);
}

.privacy-band {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 32px;
    margin: 0;
    padding: 72px max(28px, calc((100vw - 1160px) / 2));
    color: #fff;
    background-color: var(--hero);
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.about-vision {
    margin: 0;
    padding: 72px max(28px, calc((100vw - 1160px) / 2));
    color: #fff;
    background-color: var(--hero);
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.about-vision .eyebrow {
    color: #e4b184;
}

.about-vision h2 {
    margin: 0;
    font-size: 30px;
    line-height: 1.2;
}

.about-vision p:last-child {
    max-width: 920px;
    margin: 14px 0 0;
    color: var(--hero-muted);
}

.privacy-band h2 {
    margin: 0;
    font-size: 30px;
    line-height: 1.2;
}

.privacy-band p:last-child {
    max-width: 620px;
    margin: 12px 0 0;
    color: var(--hero-muted);
}

.privacy-band .eyebrow {
    color: #e4b184;
}

.button-light {
    flex: 0 0 auto;
    color: #10201b;
    background: #fff;
}

.button-light:hover {
    background: #d9f2ea;
}

.site-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 28px;
    padding: 34px 28px;
    color: var(--hero-muted);
    background: var(--hero);
}

.footer-legal {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 6px 18px;
    padding: 8px 28px;
    color: rgba(194, 210, 232, 0.72);
    background: #152640;
    border-top: 1px solid rgba(255, 255, 255, 0.06);
    font-size: 12px;
    line-height: 1.6;
}

.footer-legal a {
    color: inherit;
}

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

.site-footer p {
    margin: 8px 0 0;
    font-size: 13px;
}

.site-footer nav {
    display: flex;
    gap: 20px;
    font-size: 14px;
    font-weight: 600;
}

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

@media (max-width: 980px) {
    .hero {
        grid-template-columns: 1fr;
        padding-top: 56px;
        text-align: center;
    }

    .hero-copy {
        margin: 0 auto;
    }

    .hero-lead,
    .hero-actions {
        margin-left: auto;
        margin-right: auto;
    }

    .hero-actions {
        justify-content: center;
    }

    .hero-visual {
        min-height: 280px;
    }

    .stats {
        grid-template-columns: repeat(3, 1fr);
    }

    .stat:nth-child(3) {
        border-right: 1px solid var(--line);
    }

    .stat:nth-child(4) {
        border-left: 1px solid var(--line);
    }

    .stat:first-child,
    .stat:nth-child(4) {
        border-radius: 0;
    }

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

    .grid-three {
        grid-template-columns: repeat(2, 1fr);
    }

    .screenshot-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 680px) {
    .site-header {
        flex-wrap: wrap;
        gap: 10px;
        padding: 10px 16px;
    }

    .site-nav {
        order: 3;
        width: 100%;
        overflow-x: auto;
        gap: 14px;
        font-size: 13px;
        padding-bottom: 2px;
    }

    .header-right {
        order: 2;
    }

    .lang-toggle {
        min-height: 34px;
    }

    .lang-toggle .lang-option {
        padding: 4px 8px;
    }

    .hero {
        min-height: auto;
        padding: 48px 20px 56px;
    }

    .hero h1 {
        font-size: 46px;
    }

    .about-hero {
        padding: 48px 20px;
    }

    .about-hero h1 {
        font-size: 40px;
    }

    .hero-lead {
        font-size: 16px;
    }

    .stats {
        grid-template-columns: repeat(2, 1fr);
        margin-top: -24px;
        padding: 0 16px;
    }

    .stat {
        min-height: 96px;
        border-left: 1px solid var(--line);
    }

    .stat:nth-child(odd) {
        border-left: none;
        border-radius: 0;
    }

    .stat:first-child {
        border-radius: 8px 0 0 0;
    }

    .stat:nth-child(2) {
        border-radius: 0 8px 0 0;
    }

    .stat:nth-child(5) {
        border-radius: 0 0 0 8px;
    }

    .stat:last-child {
        border-radius: 0 0 8px 0;
    }

    .section {
        padding: 68px 16px 56px;
    }

    .section-alt {
        padding-left: 16px;
        padding-right: 16px;
    }

    .section-heading h2 {
        font-size: 28px;
    }

    .grid-four,
    .grid-five,
    .grid-three,
    .tools-layout,
    .screenshot-grid {
        grid-template-columns: 1fr;
    }

    .tools-layout .tool-item:last-child {
        grid-column: auto;
    }

    .privacy-band {
        flex-direction: column;
        align-items: flex-start;
        padding: 56px 20px;
    }

    .about-vision {
        padding: 56px 20px;
    }

    .site-footer {
        flex-direction: column;
        align-items: flex-start;
        padding: 28px 20px;
    }

    .footer-legal {
        padding: 8px 20px;
    }

    .site-footer nav {
        flex-wrap: wrap;
    }
}