:root {
    --brand: #2563eb;
    --brand-dark: #1d4ed8;
    --brand-soft: #eef4ff;
    --ink: #111827;
    --muted: #667085;
    --soft: #f5f7fb;
    --line: #e5e7eb;
    --card: #ffffff;
    --radius: 24px;
    --shadow: 0 24px 60px rgba(15, 23, 42, 0.08);
    --container: 1120px;
    --font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: var(--font);
    color: var(--ink);
    background: #fff;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

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

button {
    font: inherit;
}

.container {
    width: min(100% - 40px, var(--container));
    margin-inline: auto;
}

.skip-link {
    position: absolute;
    left: -999px;
}

.skip-link:focus {
    left: 16px;
    top: 16px;
    z-index: 100;
    padding: 10px 14px;
    border-radius: 12px;
    background: var(--brand);
    color: #fff;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    padding: 14px 0;
    background: rgba(255, 255, 255, 0.78);
    backdrop-filter: blur(16px);
}

.nav {
    height: 66px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
    padding: 9px 10px 9px 14px;
    border: 1px solid rgba(229, 231, 235, 0.9);
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.92);
    box-shadow: 0 18px 50px rgba(15, 23, 42, 0.08);
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
}

.brand-logo {
    width: 40px;
    height: 40px;
    border-radius: 14px;
    box-shadow: 0 10px 24px rgba(37, 99, 235, 0.18);
}

.brand-name {
    letter-spacing: 0.08em;
}

.desktop-nav {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 6px;
    border-radius: 999px;
    background: var(--soft);
    color: var(--muted);
    font-size: 15px;
}

.desktop-nav a {
    padding: 8px 14px;
    border-radius: 999px;
    transition: background 0.18s ease, color 0.18s ease;
}

.desktop-nav a:hover,
.footer-links a:hover {
    color: var(--brand);
}

.desktop-nav a:hover {
    background: #fff;
}

.menu-button {
    display: none;
    width: 44px;
    height: 44px;
    border: 0;
    border-radius: 999px;
    background: var(--soft);
    color: var(--ink);
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}

.menu-button span {
    width: 18px;
    height: 2px;
    border-radius: 99px;
    background: currentColor;
    transition: transform 0.2s ease, opacity 0.2s ease;
}

.menu-button.is-open span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.menu-button.is-open span:nth-child(2) {
    opacity: 0;
}

.menu-button.is-open span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

.mobile-menu {
    width: min(100% - 40px, var(--container));
    margin: 10px auto 0;
    padding: 10px;
    border: 1px solid var(--line);
    border-radius: 18px;
    background: #fff;
    box-shadow: var(--shadow);
}

.mobile-menu a {
    display: block;
    padding: 12px 14px;
    border-radius: 12px;
    color: var(--muted);
    font-weight: 600;
}

.mobile-menu a:hover {
    background: var(--soft);
    color: var(--ink);
}

.hero {
    padding: 82px 0 86px;
    text-align: center;
}

.hero-grid {
    max-width: 860px;
}

.eyebrow {
    margin: 0 0 12px;
    color: var(--brand);
    font-size: 13px;
    font-weight: 800;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.hero h1,
.section-title h2,
.split h2 {
    margin: 0;
    color: var(--ink);
    line-height: 1.15;
    letter-spacing: -0.04em;
}

.hero h1 {
    max-width: 820px;
    margin-inline: auto;
    font-size: clamp(40px, 7vw, 72px);
}

.hero-text {
    max-width: 720px;
    margin: 24px 0 0;
    margin-inline: auto;
    color: var(--muted);
    font-size: 18px;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    justify-content: center;
    margin-top: 34px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 22px;
    border-radius: 999px;
    font-weight: 700;
    transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease;
}

.btn:hover {
    transform: translateY(-1px);
}

.btn-primary {
    background: var(--brand);
    color: #fff;
    box-shadow: 0 14px 30px rgba(37, 99, 235, 0.24);
}

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

.btn-secondary {
    background: var(--soft);
    color: var(--ink);
}

.hero-notes {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
    margin-top: 26px;
}

.hero-notes span {
    padding: 8px 12px;
    border: 1px solid var(--line);
    border-radius: 999px;
    color: var(--muted);
    font-size: 14px;
    background: #fff;
}

.section {
    padding: 82px 0;
}

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

.section-title {
    max-width: 620px;
    margin: 0 auto 42px;
    text-align: center;
}

.section-title h2,
.split h2 {
    font-size: clamp(30px, 4vw, 46px);
}

.section-title p:last-child,
.muted,
.site-footer p {
    color: var(--muted);
}

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

.feature-card {
    padding: 26px;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: var(--card);
}

.feature-icon {
    display: inline-flex;
    margin-bottom: 28px;
    color: var(--brand);
    font-weight: 900;
}

.feature-card h3,
.steps h3 {
    margin: 0 0 8px;
    font-size: 20px;
}

.feature-card p,
.steps p,
.faq-list p {
    margin: 0;
    color: var(--muted);
}

.split {
    display: grid;
    grid-template-columns: 0.8fr 1.2fr;
    gap: 56px;
    align-items: center;
}

.tag-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.tag-cloud span {
    padding: 12px 16px;
    border: 1px solid var(--line);
    border-radius: 999px;
    background: #fff;
    font-weight: 700;
}

.steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
    padding: 0;
    margin: 0;
    list-style: none;
}

.steps li {
    padding: 28px;
    border-radius: var(--radius);
    background: var(--soft);
}

.steps span {
    display: grid;
    place-items: center;
    width: 42px;
    height: 42px;
    margin-bottom: 22px;
    border-radius: 14px;
    background: #fff;
    color: var(--brand);
    font-weight: 900;
}

.faq-wrap {
    max-width: 860px;
}

.faq-list {
    display: grid;
    gap: 12px;
}

.faq-list details {
    padding: 20px 22px;
    border: 1px solid var(--line);
    border-radius: 18px;
    background: #fff;
}

.faq-list summary {
    cursor: pointer;
    font-weight: 800;
}

.faq-list p {
    margin-top: 12px;
}

.site-footer {
    padding: 38px 0;
    border-top: 1px solid var(--line);
}

.footer-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 32px;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 18px;
    color: var(--muted);
    font-weight: 600;
}

@media (max-width: 960px) {
    .desktop-nav {
        display: none;
    }

    .menu-button {
        display: inline-flex;
    }

    .split {
        grid-template-columns: 1fr;
        gap: 42px;
    }

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

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

@media (max-width: 640px) {
    .container {
        width: min(100% - 28px, var(--container));
    }

    .nav {
        height: 64px;
    }

    .hero {
        padding: 58px 0 54px;
    }

    .hero h1 {
        font-size: 38px;
    }

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

    .hero-actions {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    .feature-grid,
    .steps {
        grid-template-columns: 1fr;
    }

    .section {
        padding: 62px 0;
    }
}