/* Seisin download site. Cookieless, no third-party resources.
   System font stack stands in for Merriweather/Inter; self-host those
   later for an exact brand match. */

:root {
    --accent: #2563EB;
    --accent-fg: #ffffff;
    --bg: #0a0a0f;
    --card-bg: #0f0f14;
    --border: #1e1e28;
    --text: #e8e8f0;
    --text-soft: #a0a0b8;
    --serif: Georgia, 'Times New Roman', serif;
    --sans: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
    --maxw: 960px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
    margin: 0;
    font-family: var(--sans);
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* --- Starfield
   Fixed to the viewport rather than sized to the document, so it costs one
   screen of canvas no matter how long the page gets. Content sits above it;
   the opaque cards and download box occlude it where text needs contrast. */
#stars {
    position: fixed; inset: 0;
    width: 100%; height: 100%;
    z-index: 0; pointer-events: none;
}
main, footer { position: relative; z-index: 1; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.wrap.narrow { max-width: 680px; }
.center { text-align: center; margin-left: auto; margin-right: auto; }
.download-note { margin: 0 auto 4px; }

/* --- Top nav */
header.nav {
    position: sticky; top: 0; z-index: 10;
    background: rgba(10, 10, 15, 0.85);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
}
.nav-inner {
    display: flex; align-items: center; justify-content: space-between;
    height: 76px;
}
.logo-icon { height: 62px; width: auto; display: block; }
.nav-links a { margin-left: 24px; color: var(--text-soft); font-size: 15px; }
.nav-links a:hover { color: var(--text); text-decoration: none; }

/* --- Buttons */
.btn {
    display: inline-block;
    padding: 16px 36px; border-radius: 11px;
    background: var(--accent); color: var(--accent-fg);
    font-weight: 600; font-size: 17px;
    border: 1px solid var(--accent);
}
.btn:hover { text-decoration: none; opacity: 0.92; }

/* --- Hero */
.hero { text-align: center; padding: 100px 0 76px; }
.hero h1 {
    font-family: var(--serif); font-weight: 400; color: var(--text);
    font-size: 72px; letter-spacing: 0.14em; margin: 0 0 20px;
}
.hero p.lead {
    font-size: 24px; color: var(--text-soft);
    max-width: 620px; margin: 0 auto;
}
.hero .actions { margin-top: 36px; }
.hero-meta { color: var(--text-soft); font-size: 16px; margin: 28px 0 0; }
/* Secondary (ghost) button: reads as a button without competing with the
   solid Download CTA in the download section. */
.scroll-cue {
    display: inline-block; margin-top: 20px;
    padding: 14px 32px; border-radius: 11px;
    border: 1px solid var(--border);
    background: var(--card-bg); color: var(--text);
    font-weight: 600; font-size: 16px; letter-spacing: 0.02em;
}
.scroll-cue:hover {
    text-decoration: none; border-color: var(--accent);
    color: var(--text);
}

/* --- Sections */
section { padding: 76px 0; border-top: 1px solid var(--border); text-align: center; }
section h2 {
    font-family: var(--serif); font-weight: 400; font-size: 40px;
    letter-spacing: 0.02em; margin: 0 0 14px;
}
section .sub {
    color: var(--text-soft); margin: 0 auto 40px; font-size: 19px;
    max-width: 680px; line-height: 1.75;
}

/* --- Features grid */
.grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.card {
    background: var(--card-bg); border: 1px solid var(--border);
    border-radius: 14px; padding: 30px; text-align: center;
}
.card h3 { margin: 0 0 10px; font-size: 20px; }
.card p { margin: 0; color: var(--text-soft); font-size: 16px; line-height: 1.65; }

/* --- Showcase carousel */
.wide-wrap { max-width: 1120px; }

.carousel { margin-top: 8px; }

/* viewport clips the sliding track; arrows sit on top of it */
.carousel-viewport {
    position: relative; overflow: hidden;
    border: 1px solid var(--border); border-radius: 16px;
    background: var(--card-bg); outline: none;
}
.carousel-viewport:focus-visible { border-color: var(--accent); }

.carousel-track {
    display: flex;
    transition: transform 0.5s ease;
}
.slide { flex: 0 0 100%; }
.slide img {
    display: block; width: 100%; height: auto;
    /* holds height so arrows stay centered before images load */
    min-height: 200px; background: var(--card-bg);
}

/* prev / next */
.car-btn {
    position: absolute; top: 50%; transform: translateY(-50%);
    width: 46px; height: 46px; border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    border: 1px solid var(--border);
    background: rgba(15, 15, 20, 0.72); backdrop-filter: blur(6px);
    color: var(--text); font-size: 26px; line-height: 1;
    cursor: pointer; padding: 0; transition: border-color 0.15s, background 0.15s;
}
.car-btn:hover { border-color: var(--accent); background: rgba(15, 15, 20, 0.9); }
.car-btn.prev { left: 16px; }
.car-btn.next { right: 16px; }

.car-caption {
    text-align: center; color: var(--text-soft);
    font-size: 16px; margin: 18px 0 0;
}

/* dots act as a clickable album index */
.car-dots {
    display: flex; justify-content: center; gap: 10px; margin-top: 16px;
}
.car-dots button {
    width: 9px; height: 9px; padding: 0; border-radius: 50%;
    border: none; cursor: pointer; background: var(--border);
    transition: background 0.15s, transform 0.15s;
}
.car-dots button:hover { background: var(--text-soft); }
.car-dots button[aria-selected="true"] {
    background: var(--accent); transform: scale(1.25);
}

@media (prefers-reduced-motion: reduce) {
    .carousel-track { transition: none; }
}

/* --- Download block */
.download-box {
    background: var(--card-bg); border: 1px solid var(--border);
    border-radius: 16px; padding: 52px 40px; text-align: center;
}
.download-box .actions { margin: 28px 0 8px; }
.note {
    margin-top: 20px; font-size: 15px; color: var(--text-soft); line-height: 1.6;
    max-width: 600px; margin-left: auto; margin-right: auto;
}

/* --- Footer */
footer {
    border-top: 1px solid var(--border);
    padding: 40px 0; color: var(--text-soft); font-size: 13px;
    text-align: center;
}
footer .foot-inner { display: flex; flex-direction: column; align-items: center; gap: 12px; }
footer .foot-links a { color: var(--text-soft); margin: 0 9px; }

/* --- Legal pages */
.legal { padding: 80px 0; }
.legal h1 { font-family: var(--serif); font-weight: 400; font-size: 38px; margin: 0 0 8px; }
.legal h2 { font-family: var(--serif); font-weight: 400; font-size: 22px; margin: 36px 0 8px; }
.legal p, .legal li { color: var(--text-soft); }
.legal .updated { font-size: 13px; color: var(--text-soft); margin-bottom: 32px; }
/* Ghost button, matching .scroll-cue but sized down for a secondary action. */
.back {
    display: inline-block; margin-bottom: 32px;
    padding: 10px 22px; border-radius: 9px;
    border: 1px solid var(--border);
    background: var(--card-bg); color: var(--text);
    font-weight: 600; font-size: 14px; letter-spacing: 0.02em;
}
.back:hover {
    text-decoration: none; border-color: var(--accent);
    color: var(--text);
}

@media (max-width: 680px) {
    .hero h1 { font-size: 40px; }
    .grid { grid-template-columns: 1fr; }
    .car-btn { width: 38px; height: 38px; font-size: 22px; }
    .car-btn.prev { left: 8px; }
    .car-btn.next { right: 8px; }
    .nav-links a { margin-left: 16px; }
    .nav-links a.hide-sm { display: none; }
}