:root {
    --ink: #071a3b;
    --muted: #5a6d8d;
    --line: #dbe5f4;
    --blue: #2563eb;
    --blue-dark: #1746bb;
    --cyan: #13b7d6;
    --soft: #f3f7fd;
    --white: #ffffff;
    --green: #18a66a;
    --shadow: 0 20px 55px rgba(25, 67, 132, 0.12);
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    color: var(--ink);
    background: var(--white);
    font-family: Inter, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

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

button {
    font: inherit;
    cursor: pointer;
}

.container {
    width: min(1180px, calc(100% - 48px));
    margin: 0 auto;
}

.section {
    padding: 108px 0;
}

.section-soft {
    background: var(--soft);
}

.eyebrow,
.kicker {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--blue);
    font-size: 12px;
    font-weight: 800;
    letter-spacing: .1em;
    text-transform: uppercase;
}

.eyebrow::before {
    width: 7px;
    height: 7px;
    content: "";
    border-radius: 50%;
    background: var(--cyan);
    box-shadow: 0 0 0 4px rgba(19, 183, 214, .14);
}

h1,
h2,
h3,
p {
    margin-top: 0;
}

h1,
h2,
h3 {
    letter-spacing: -.045em;
}

h1 {
    max-width: 720px;
    margin-bottom: 22px;
    font-size: clamp(44px, 6vw, 76px);
    line-height: 1.05;
}

h2 {
    margin: 14px 0;
    font-size: clamp(34px, 4vw, 54px);
    line-height: 1.12;
}

h3 {
    margin-bottom: 8px;
    font-size: 20px;
    line-height: 1.3;
}

p {
    color: var(--muted);
}

.announcement {
    color: #dceaff;
    background: #071a3b;
    font-size: 13px;
}

.announcement-inner {
    display: flex;
    min-height: 40px;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.announcement a {
    margin-left: 10px;
    color: #ffffff;
    font-weight: 800;
}

.site-header {
    position: sticky;
    z-index: 20;
    top: 0;
    border-bottom: 1px solid rgba(219, 229, 244, .9);
    background: rgba(255, 255, 255, .9);
    backdrop-filter: blur(16px);
}

.header-inner {
    display: flex;
    height: 76px;
    align-items: center;
    gap: 28px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 850;
    letter-spacing: -.04em;
}

.brand-logo {
    width: 35px;
    height: 35px;
    border-radius: 10px;
    box-shadow: 0 8px 22px rgba(37, 99, 235, .22);
    object-fit: cover;
}

.header-nav {
    display: flex;
    margin-left: auto;
    gap: 28px;
}

.header-nav a,
.header-link {
    color: var(--muted);
    font-size: 14px;
    font-weight: 650;
}

.header-nav a:hover,
.header-link:hover {
    color: var(--blue);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.btn {
    display: inline-flex;
    min-height: 46px;
    align-items: center;
    justify-content: center;
    gap: 9px;
    padding: 0 19px;
    border: 1px solid transparent;
    border-radius: 11px;
    font-size: 14px;
    font-weight: 800;
    transition: .2s ease;
}

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

.btn-primary {
    color: #ffffff;
    background: var(--blue);
    box-shadow: 0 12px 24px rgba(37, 99, 235, .2);
}

.btn-primary:hover {
    background: var(--blue-dark);
}

.btn-outline {
    color: var(--blue);
    border-color: #bcd2f4;
    background: #ffffff;
}

.btn-outline:hover {
    background: #eff6ff;
}

.menu-toggle,
.mobile-nav {
    display: none;
}

.hero {
    overflow: hidden;
    background: linear-gradient(135deg, #f6faff 0%, #ffffff 72%);
}

.hero-grid {
    display: grid;
    min-height: 670px;
    grid-template-columns: 1.05fr .95fr;
    align-items: center;
    gap: 70px;
}

.hero-copy > p {
    max-width: 610px;
    font-size: 17px;
    line-height: 1.9;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 30px;
}

.hero-note {
    margin-top: 18px;
    color: var(--muted);
    font-size: 13px;
}

.check {
    color: var(--green);
    font-weight: 900;
}

.hero-panel {
    position: relative;
    padding: 28px;
    border: 1px solid #d9e7fa;
    border-radius: 26px;
    background: rgba(255, 255, 255, .86);
    box-shadow: var(--shadow);
}

.hero-panel::before {
    position: absolute;
    z-index: -1;
    width: 330px;
    height: 330px;
    content: "";
    border-radius: 50%;
    background: rgba(107, 196, 255, .25);
    filter: blur(18px);
    inset: 25% 8% auto auto;
}

.panel-head,
.panel-row,
.panel-status,
.version-head,
.version-row,
.download-item,
.footer-bottom {
    display: flex;
    align-items: center;
}

.panel-head,
.version-head,
.footer-bottom {
    justify-content: space-between;
}

.panel-head {
    color: var(--muted);
    font-size: 12px;
    font-weight: 800;
    letter-spacing: .08em;
}

.panel-icon {
    display: grid;
    width: 132px;
    height: 132px;
    margin: 38px auto 20px;
    place-items: center;
    border: 10px solid #dbeafe;
    border-top-color: var(--blue);
    border-right-color: var(--cyan);
    border-radius: 50%;
    color: var(--blue);
    background: #ffffff;
    box-shadow: 0 18px 30px rgba(37, 99, 235, .16);
}

.panel-icon img {
    width: 58px;
    height: 58px;
    border-radius: 16px;
}

.hero-panel h3,
.hero-panel > p {
    text-align: center;
}

.hero-panel > p {
    margin-bottom: 24px;
    font-size: 13px;
}

.panel-status {
    justify-content: center;
    gap: 7px;
    color: var(--green);
    font-size: 12px;
    font-weight: 800;
}

.panel-status::before {
    width: 7px;
    height: 7px;
    content: "";
    border-radius: 50%;
    background: var(--green);
}

.panel-row {
    justify-content: space-between;
    padding-top: 17px;
    border-top: 1px solid var(--line);
    color: var(--muted);
    font-size: 12px;
}

.panel-row strong {
    color: var(--ink);
}

.metrics {
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
}

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

.metric {
    display: flex;
    min-height: 92px;
    align-items: baseline;
    justify-content: center;
    gap: 8px;
    border-right: 1px solid var(--line);
}

.metric:last-child {
    border-right: 0;
}

.metric strong {
    font-size: 30px;
    letter-spacing: -.06em;
}

.metric span {
    color: var(--muted);
    font-size: 13px;
}

.section-heading {
    margin-bottom: 48px;
}

.section-heading.center {
    max-width: 730px;
    margin-right: auto;
    margin-left: auto;
    text-align: center;
}

.section-heading.center p {
    margin-right: auto;
    margin-left: auto;
}

.section-heading.split {
    display: flex;
    align-items: end;
    justify-content: space-between;
    gap: 40px;
}

.section-heading.split > p {
    max-width: 390px;
}

.version-layout,
.requirement-layout,
.update-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    align-items: center;
    gap: 90px;
}

.version-card {
    padding: 28px;
    border: 1px solid #cfe0f8;
    border-radius: 22px;
    background: linear-gradient(145deg, #ffffff, #edf5ff);
    box-shadow: 0 18px 44px rgba(37, 99, 235, .08);
}

.version-number {
    color: var(--blue);
    font-size: 52px;
    font-weight: 850;
    letter-spacing: -.08em;
}

.version-head {
    padding-bottom: 20px;
    border-bottom: 1px solid #dbe5f4;
}

.version-head span,
.version-row span {
    color: var(--muted);
    font-size: 13px;
}

.version-row {
    justify-content: space-between;
    gap: 20px;
    padding: 15px 0;
    border-bottom: 1px solid #dbe5f4;
    font-size: 13px;
}

.version-row:last-child {
    border-bottom: 0;
}

.platform-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.platform-card {
    display: flex;
    min-height: 350px;
    flex-direction: column;
    padding: 24px;
    border: 1px solid var(--line);
    border-radius: 20px;
    background: #ffffff;
    transition: .2s ease;
}

.platform-card:hover {
    transform: translateY(-4px);
    border-color: #a9c7f5;
    box-shadow: var(--shadow);
}

.platform-card.featured {
    border: 2px solid #79a8f3;
}

.platform-icon {
    display: grid;
    width: 46px;
    height: 46px;
    place-items: center;
    border-radius: 13px;
    color: var(--blue);
    background: #eaf2ff;
    font-size: 22px;
}

.platform-card h3 {
    margin-top: 22px;
    font-size: 22px;
}

.platform-card p {
    min-height: 76px;
    font-size: 13px;
}

.platform-meta {
    display: flex;
    justify-content: space-between;
    gap: 10px;
    margin-top: auto;
    padding: 15px 0;
    border-top: 1px solid var(--line);
    color: var(--muted);
    font-size: 11px;
}

.platform-card .btn {
    width: 100%;
}

.choose-grid,
.check-grid,
.steps-grid,
.after-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.choose-card,
.check-card,
.step-card,
.after-card {
    padding: 26px;
    border: 1px solid var(--line);
    border-radius: 18px;
    background: #ffffff;
    transition: .2s ease;
}

.choose-card:hover,
.check-card:hover,
.step-card:hover,
.after-card:hover {
    transform: translateY(-4px);
    border-color: #a9c7f5;
    box-shadow: var(--shadow);
}

.card-icon,
.number {
    color: var(--blue);
    font-size: 13px;
    font-weight: 850;
    letter-spacing: .08em;
}

.choose-card h3,
.check-card h3,
.step-card h3,
.after-card h3 {
    margin-top: 18px;
}

.choose-card p,
.check-card p,
.step-card p,
.after-card p {
    font-size: 13px;
}

.inline-link {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    margin-top: 16px;
    color: var(--blue);
    font-size: 13px;
    font-weight: 800;
}

.requirement-panel {
    padding: 28px;
    border-radius: 22px;
    color: #e5efff;
    background: linear-gradient(145deg, #071a3b, #12326b);
    box-shadow: 0 25px 55px rgba(7, 26, 59, .2);
}

.requirement-panel .panel-head,
.requirement-panel .panel-row {
    color: #bcd2f4;
}

.requirement-panel .panel-row {
    border-color: rgba(188, 210, 244, .17);
}

.requirement-panel .panel-row strong {
    color: #ffffff;
}

.comparison-wrap {
    overflow-x: auto;
    border: 1px solid var(--line);
    border-radius: 18px;
    background: #ffffff;
    box-shadow: 0 16px 38px rgba(15, 43, 90, .06);
}

.comparison-table {
    width: 100%;
    min-width: 720px;
    border-collapse: collapse;
}

.comparison-table th,
.comparison-table td {
    padding: 17px 21px;
    border-bottom: 1px solid var(--line);
    text-align: left;
    font-size: 13px;
}

.comparison-table th {
    color: var(--muted);
    background: #eff6ff;
    font-size: 12px;
}

.comparison-table tr:last-child td {
    border-bottom: 0;
}

.update-points {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

.update-points div {
    padding: 20px;
    border: 1px solid var(--line);
    border-radius: 16px;
    background: #ffffff;
}

.update-points strong,
.update-points span {
    display: block;
}

.update-points strong {
    margin-bottom: 6px;
    font-size: 14px;
}

.update-points span {
    color: var(--muted);
    font-size: 12px;
}

.faq-layout {
    display: grid;
    grid-template-columns: .75fr 1.25fr;
    gap: 90px;
}

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

details {
    border-bottom: 1px solid var(--line);
}

summary {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    padding: 20px 0;
    cursor: pointer;
    list-style: none;
    font-size: 15px;
    font-weight: 800;
}

summary::-webkit-details-marker {
    display: none;
}

summary span {
    color: var(--blue);
    font-size: 21px;
    transition: .2s ease;
}

details[open] summary span {
    transform: rotate(45deg);
}

details p {
    padding: 0 30px 20px 0;
    font-size: 13px;
}

.site-footer {
    padding-top: 66px;
    color: #c4d2e9;
    background: #071a3b;
}

.footer-main {
    display: grid;
    grid-template-columns: 1fr 1.1fr;
    gap: 80px;
    padding-bottom: 48px;
}

.footer-brand .brand {
    color: #ffffff;
}

.footer-brand p {
    margin: 16px 0;
    color: #8da4c8;
    font-size: 13px;
}

.footer-trust {
    display: flex;
    flex-wrap: wrap;
    gap: 10px 18px;
}

.footer-trust a {
    color: #9eb3d4;
    font-size: 12px;
}

.footer-trust a:hover {
    color: #ffffff;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 36px;
}

.footer-links strong,
.footer-links a {
    display: block;
}

.footer-links strong {
    margin-bottom: 15px;
    color: #ffffff;
    font-size: 13px;
}

.footer-links a {
    margin-bottom: 10px;
    color: #9eb3d4;
    font-size: 12px;
}

.footer-links a:hover {
    color: #ffffff;
}

.footer-bottom {
    min-height: 66px;
    border-top: 1px solid rgba(157, 180, 220, .18);
    color: #7189b2;
    font-size: 11px;
}

@media (max-width: 980px) {
    .hero-grid,
    .version-layout,
    .requirement-layout,
    .update-layout {
        gap: 48px;
    }

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

@media (max-width: 760px) {
    .container {
        width: min(100% - 36px, 620px);
    }

    .section {
        padding: 76px 0;
    }

    .header-nav,
    .header-link {
        display: none;
    }

    .menu-toggle {
        display: flex;
        width: 42px;
        height: 42px;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: 4px;
        border: 1px solid var(--line);
        border-radius: 10px;
        background: #ffffff;
    }

    .menu-toggle span {
        width: 17px;
        height: 2px;
        border-radius: 2px;
        background: var(--ink);
    }

    .mobile-nav {
        position: absolute;
        top: 76px;
        right: 0;
        left: 0;
        display: none;
        padding: 14px 18px 22px;
        border-bottom: 1px solid var(--line);
        background: #ffffff;
    }

    .mobile-nav.open {
        display: flex;
        flex-direction: column;
        gap: 8px;
    }

    .mobile-nav a:not(.btn) {
        padding: 9px 4px;
        color: var(--muted);
        font-size: 14px;
    }

    .hero-grid,
    .version-layout,
    .requirement-layout,
    .update-layout,
    .faq-layout {
        grid-template-columns: 1fr;
        gap: 44px;
    }

    .hero-grid {
        min-height: auto;
    }

    h1 {
        font-size: 43px;
    }

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

    .metric {
        min-height: 76px;
        border-bottom: 1px solid var(--line);
    }

    .metric:nth-child(2n) {
        border-right: 0;
    }

    .platform-grid,
    .choose-grid,
    .check-grid,
    .steps-grid,
    .after-grid {
        grid-template-columns: 1fr;
    }

    .section-heading.split {
        display: block;
    }

    .section-heading.split > p {
        margin-top: 16px;
    }

    .footer-main {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .footer-bottom {
        align-items: flex-start;
        flex-direction: column;
        justify-content: center;
        gap: 5px;
    }
}

@media (max-width: 480px) {
    .header-actions .btn {
        display: none;
    }

    .hero-actions .btn {
        width: 100%;
    }

    .hero-panel {
        padding: 22px;
    }

    .update-points,
    .footer-links {
        grid-template-columns: 1fr 1fr;
    }
}

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

    *,
    *::before,
    *::after {
        transition: none !important;
    }
}