:root {
    color-scheme: light dark;
    --bg: #f4fbfc;
    --bg-card: #ffffff;
    --ink: #0e1f25;
    --ink-soft: #4d6671;
    --rule: rgba(14, 31, 37, 0.08);
    --accent: #0bb5d4;
    --accent-deep: #088aa3;
    --accent-soft: rgba(11, 181, 212, 0.12);
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #0b1418;
        --bg-card: #122026;
        --ink: #e8f4f7;
        --ink-soft: #9fb5be;
        --rule: rgba(255, 255, 255, 0.08);
        --accent: #4ed1ea;
        --accent-deep: #6fdcf0;
        --accent-soft: rgba(78, 209, 234, 0.14);
    }
}

* {
    box-sizing: border-box;
}

html, body {
    margin: 0;
    padding: 0;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", sans-serif;
    background: var(--bg);
    color: var(--ink);
    line-height: 1.55;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

main {
    max-width: 760px;
    margin: 0 auto;
    padding: 64px 24px 96px;
}

.hero {
    text-align: center;
    padding: 24px 0 56px;
    border-bottom: 1px solid var(--rule);
}

.mascot {
    width: 220px;
    height: 220px;
    image-rendering: -webkit-optimize-contrast;
    filter: drop-shadow(0 18px 24px rgba(11, 181, 212, 0.18));
    animation: idle-sway 1.6s ease-in-out infinite alternate;
}

@keyframes idle-sway {
    from { transform: translateY(0) rotate(2deg); transform-origin: bottom center; }
    to   { transform: translateY(-4px) rotate(-2deg); transform-origin: bottom center; }
}

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

h1 {
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", sans-serif;
    font-size: 56px;
    letter-spacing: -0.02em;
    margin: 8px 0 8px;
    font-weight: 700;
}

.tagline {
    font-size: 20px;
    color: var(--ink-soft);
    margin: 0 0 32px;
}

.download {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    background: var(--accent);
    color: white;
    text-decoration: none;
    padding: 14px 28px;
    border-radius: 12px;
    font-weight: 600;
    box-shadow: 0 8px 20px rgba(11, 181, 212, 0.32);
    transition: transform 0.12s ease, box-shadow 0.12s ease, background 0.12s ease;
}

.download:hover {
    background: var(--accent-deep);
    transform: translateY(-1px);
    box-shadow: 0 10px 24px rgba(11, 181, 212, 0.4);
}

.download:active {
    transform: translateY(0);
}

.download-label {
    font-size: 17px;
}

.download-meta {
    font-size: 12px;
    opacity: 0.85;
    font-weight: 500;
}

.features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 28px;
    padding: 56px 0;
}

@media (max-width: 600px) {
    .features { grid-template-columns: 1fr; }
    main { padding: 40px 20px 64px; }
    h1 { font-size: 44px; }
    .mascot { width: 180px; height: 180px; }
}

.features article {
    background: var(--bg-card);
    border: 1px solid var(--rule);
    border-radius: 14px;
    padding: 22px 24px;
}

.features h2 {
    margin: 0 0 8px;
    font-size: 17px;
    font-weight: 600;
    color: var(--accent-deep);
}

.features p {
    margin: 0;
    color: var(--ink-soft);
    font-size: 15px;
}

footer {
    text-align: center;
    color: var(--ink-soft);
    font-size: 14px;
    padding-top: 24px;
    border-top: 1px solid var(--rule);
}

footer a {
    color: var(--ink-soft);
    text-decoration: underline;
    text-decoration-color: var(--accent-soft);
    text-underline-offset: 3px;
}

footer a:hover {
    color: var(--accent-deep);
}

.footnote {
    font-size: 12px;
    margin-top: 12px;
    opacity: 0.7;
}