:root {
    color-scheme: light dark;
    --text: #15172b;
    --muted: #5d6280;
    --background: #f6f5ff;
    --surface: #ffffff;
    --line: #e4e2f5;
    --blue: #3966ff;
    --violet: #7f3bff;
    --lilac: #bd91ff;
    --link: #4b4ff0;
}

@media (prefers-color-scheme: dark) {
    :root {
        --text: #eceaff;
        --muted: #a3a6c4;
        --background: #0d0e1c;
        --surface: #17192e;
        --line: #272a45;
        --link: #a9a5ff;
    }
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    background: var(--background);
    color: var(--text);
    font: 17px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

a {
    color: var(--link);
}

.page {
    max-width: 1040px;
    margin: 0 auto;
    padding: 0 16px;
}

header {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 24px 0;
}

header a {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text);
    font-weight: 700;
    font-size: 19px;
    text-decoration: none;
}

header img {
    width: 36px;
    height: 36px;
}

.hero {
    display: grid;
    grid-template-columns: 1.1fr 1fr;
    align-items: center;
    gap: 48px;
    padding: 48px 0 80px;
}

.hero h1 {
    margin: 0 0 20px;
    font-size: clamp(40px, 6vw, 64px);
    line-height: 1.05;
    letter-spacing: -0.03em;
}

.hero h1 span {
    background: linear-gradient(90deg, var(--blue), var(--violet));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.hero p {
    margin: 0 0 28px;
    color: var(--muted);
    font-size: 20px;
}

.badge {
    display: inline-block;
    padding: 12px 22px;
    border-radius: 999px;
    background: linear-gradient(90deg, var(--blue), var(--violet));
    color: #fff;
    font-weight: 600;
}

.requires {
    margin-top: 14px;
    color: var(--muted);
    font-size: 15px;
}

.stack {
    position: relative;
    width: min(100%, 360px);
    aspect-ratio: 1.45;
    margin: 0 auto;
}

.card {
    position: absolute;
    inset: 0;
    border-radius: 32px;
    border: 3px solid rgba(255, 255, 255, 0.6);
}

.card.back {
    transform: translateY(-44px) scale(0.84);
    background: linear-gradient(var(--lilac), #c9a8ff);
}

.card.middle {
    transform: translateY(-22px) scale(0.92);
    background: linear-gradient(#9676ff, var(--violet));
}

.card.front {
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 0 36px;
    background: linear-gradient(#6690ff, var(--blue));
    color: #fff;
    box-shadow: 0 24px 60px rgba(57, 102, 255, 0.35);
    animation: flip 0.7s cubic-bezier(0.2, 0.8, 0.2, 1) 0.3s both;
}

.card .time {
    font-size: clamp(48px, 9vw, 72px);
    font-weight: 300;
    line-height: 1;
    letter-spacing: -0.02em;
}

.card .date {
    margin-top: 10px;
    opacity: 0.85;
    font-size: 18px;
}

.dots {
    position: absolute;
    top: 50%;
    right: 18px;
    display: flex;
    flex-direction: column;
    gap: 6px;
    transform: translateY(-50%);
}

.dots i {
    width: 8px;
    height: 8px;
    border-radius: 4px;
    background: rgba(255, 255, 255, 0.55);
}

.dots i:first-child {
    height: 22px;
    background: #fff;
}

@keyframes flip {
    from {
        transform: translateY(40px);
    }
}

.features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    padding-bottom: 80px;
}

.feature {
    padding: 28px;
    border: 1px solid var(--line);
    border-radius: 24px;
    background: var(--surface);
}

.feature h2 {
    margin: 0 0 8px;
    font-size: 21px;
}

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

footer {
    display: flex;
    flex-wrap: wrap;
    gap: 8px 24px;
    padding: 28px 0 48px;
    border-top: 1px solid var(--line);
    color: var(--muted);
    font-size: 15px;
}

footer a {
    color: var(--muted);
}

footer .by {
    margin-left: auto;
}

.doc {
    max-width: 720px;
    padding-bottom: 64px;
}

.doc h1 {
    margin: 16px 0 4px;
    font-size: 36px;
    line-height: 1.15;
    letter-spacing: -0.02em;
}

.doc h2 {
    margin-top: 2em;
    font-size: 21px;
}

.doc .updated {
    color: var(--muted);
}

@media (prefers-reduced-motion: reduce) {
    .card.front {
        animation: none;
    }
}

@media (max-width: 760px) {
    .hero {
        grid-template-columns: 1fr;
        gap: 56px;
        padding-top: 24px;
    }

    .features {
        grid-template-columns: 1fr;
    }

    footer .by {
        margin-left: 0;
    }
}