:root {
    --page: #f5f5f7;
    --surface: rgba(255,255,255,.82);
    --surface-solid: #fff;
    --ink: #1d1d1f;
    --muted: #6e6e73;
    --line: rgba(0,0,0,.09);
    --blue: #0071e3;
    --blue-hover: #0077ed;
    --shadow: 0 18px 50px rgba(0,0,0,.07);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
    margin: 0;
    min-width: 320px;
    color: var(--ink);
    background:
        radial-gradient(circle at 50% -10%, rgba(0,113,227,.10), transparent 34rem),
        var(--page);
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display",
        "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--blue);
    text-decoration: none;
    transition: color .16s ease, opacity .16s ease;
}

a:hover {
    color: var(--blue-hover);
    text-decoration: underline;
}

.page {
    min-height: 100svh;
    display: flex;
    flex-direction: column;
}

main {
    width: min(1080px, calc(100% - 40px));
    margin: 0 auto;
    padding: 72px 0 90px;
    flex: 1;
}

.hero {
    padding: 42px 0 58px;
    text-align: center;
}

.logo {
    width: 104px;
    height: 104px;
    object-fit: contain;
    border-radius: 24px;
    box-shadow: 0 16px 36px rgba(0,0,0,.10);
}

.hero h1 {
    margin: 26px 0 10px;
    font-size: clamp(32px, 6vw, 52px);
    line-height: 1.12;
    letter-spacing: -1.8px;
}

.hero p {
    max-width: 620px;
    margin: 0 auto;
    color: var(--muted);
    font-size: 17px;
}

.section-title {
    margin: 48px 0 20px;
    font-size: 25px;
    letter-spacing: -.6px;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0,1fr));
    gap: 18px;
}

.card {
    display: block;
    padding: 27px;
    color: var(--ink);
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 20px;
    box-shadow: 0 8px 30px rgba(0,0,0,.045);
    backdrop-filter: blur(16px);
    transition:
        transform .18s ease,
        box-shadow .18s ease,
        border-color .18s ease;
}

.card:hover {
    color: var(--ink);
    text-decoration: none;
    transform: translateY(-3px);
    box-shadow: var(--shadow);
    border-color: rgba(0,113,227,.18);
}

.card h2,
.card h3 {
    margin: 0 0 8px;
    font-size: 21px;
    letter-spacing: -.35px;
}

.card p {
    margin: 0 0 16px;
    color: var(--muted);
}

.card .link {
    font-size: 15px;
    font-weight: 500;
}

.content {
    max-width: 800px;
    margin: 0 auto;
}

.content h1 {
    margin: 0 0 12px;
    font-size: clamp(32px,5vw,44px);
    line-height: 1.2;
    letter-spacing: -1.2px;
}

.content > .lead {
    margin: 0 0 38px;
    color: var(--muted);
    font-size: 17px;
}

.content h2 {
    margin: 42px 0 12px;
    font-size: 25px;
    letter-spacing: -.55px;
}

.content h3 {
    margin: 30px 0 10px;
    font-size: 19px;
}

.content h4 {
    margin-top: 34px;
    color: var(--muted);
}

.content p {
    margin: 10px 0;
}

.content .panel {
    margin: 18px 0;
    padding: 22px 25px;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 17px;
    box-shadow: 0 8px 28px rgba(0,0,0,.045);
}

.content .quote {
    padding-left: 18px;
    border-left: 3px solid var(--blue);
    color: var(--muted);
}

.back {
    display: inline-block;
    margin-bottom: 28px;
    font-size: 14px;
}

.site-footer {
    padding: 22px 20px 28px;
    color: var(--muted);
    font-size: 12px;
    text-align: center;
    border-top: 1px solid var(--line);
}

@media (max-width: 680px) {
    main {
        width: min(100% - 28px, 560px);
        padding: 40px 0 60px;
    }

    .hero {
        padding: 26px 0 38px;
    }

    .hero h1 {
        letter-spacing: -1.1px;
    }

    .hero p {
        font-size: 15px;
    }

    .card-grid {
        grid-template-columns: 1fr;
        gap: 14px;
    }

    .card {
        padding: 23px;
        border-radius: 17px;
    }

    .content h2 {
        margin-top: 34px;
    }
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        scroll-behavior: auto;
    }

    * {
        transition-duration: .01ms !important;
    }
}