:root {
  --paper-50:  #f7f5ef;
  --paper-100: #efeae0;
  --paper-200: #e3dccd;
  --paper-300: #cfc6b3;
  --paper-500: #847c69;
  --paper-700: #4a4538;
  --paper-900: #1f1c14;
  --ink:       #14181d;
  --ink-soft:  #2c333d;
  --accent:    #0a5a80;
  --accent-2:  #1b8cbf;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--paper-50);
  color: var(--ink);
  font-family: ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", "Inter", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

body {
  background-image:
    linear-gradient(to right, rgba(20,24,29,0.025) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(20,24,29,0.025) 1px, transparent 1px);
  background-size: 24px 24px;
  min-height: 100vh;
}

a { color: var(--accent); text-decoration: none; border-bottom: 1px solid rgba(10,90,128,0.25); }
a:hover { color: var(--accent-2); border-bottom-color: var(--accent-2); }

.page { max-width: 980px; margin: 0 auto; padding: 64px 24px 96px; }

/* hero */
.hero { padding: 24px 0 48px; border-bottom: 1px solid var(--paper-200); margin-bottom: 48px; }
.hero h1 { font-family: ui-monospace, "SF Mono", Menlo, monospace; font-size: 56px; font-weight: 600; letter-spacing: -0.02em; margin: 0 0 16px; color: var(--ink); }
.hero .eyebrow { font-family: ui-monospace, "SF Mono", Menlo, monospace; font-size: 11px; letter-spacing: 0.15em; text-transform: uppercase; color: var(--paper-500); margin: 0 0 12px; }
.hero .lead { font-size: 17px; color: var(--ink-soft); max-width: 64ch; margin: 0; }

/* version cards */
.versions { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.version-card { display: block; border: 1px solid var(--paper-300); background: white; transition: transform 0.15s ease, box-shadow 0.15s ease; }
.version-card:hover { transform: translateY(-2px); box-shadow: 0 4px 0 var(--paper-200); }
.version-link { display: flex; flex-direction: column; height: 100%; color: inherit; border-bottom: none; }
.version-link:hover { color: inherit; }

.version-cover { position: relative; aspect-ratio: 16 / 10; background: var(--paper-100); border-bottom: 1px solid var(--paper-200); overflow: hidden; }
.version-cover img { display: block; width: 100%; height: 100%; object-fit: cover; position: relative; z-index: 1; }
.version-cover img:not([src]),
.version-cover img[src=""] { display: none; }
/* fallback when img fails to load */
.cover-fallback {
  position: absolute; inset: 0; display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  font-family: ui-monospace, "SF Mono", Menlo, monospace; font-size: 13px;
  color: var(--paper-500); text-align: center; letter-spacing: 0.1em;
  text-transform: uppercase; z-index: 0;
  background-image:
    linear-gradient(to right, rgba(20,24,29,0.04) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(20,24,29,0.04) 1px, transparent 1px);
  background-size: 24px 24px;
}
.cover-hint { font-size: 11px; letter-spacing: 0; text-transform: none; color: var(--paper-300); margin-top: 8px; }

.version-meta { padding: 20px 24px 24px; display: flex; flex-direction: column; gap: 12px; flex: 1 1 auto; }
.version-tag { font-family: ui-monospace, "SF Mono", Menlo, monospace; font-size: 11px; letter-spacing: 0.15em; text-transform: uppercase; color: white; background: var(--accent); padding: 3px 8px; align-self: flex-start; }
.version-title { font-family: ui-monospace, "SF Mono", Menlo, monospace; font-size: 22px; font-weight: 600; margin: 0; color: var(--ink); letter-spacing: -0.01em; }
.version-desc { margin: 0; color: var(--ink-soft); font-size: 15px; flex: 1 1 auto; }
.version-cta { font-family: ui-monospace, "SF Mono", Menlo, monospace; font-size: 13px; color: var(--accent); margin-top: 8px; align-self: flex-start; border-bottom: 1px solid rgba(10,90,128,0.25); padding-bottom: 1px; }
.version-card:hover .version-cta { color: var(--accent-2); border-bottom-color: var(--accent-2); }

/* footer */
.footer { margin-top: 64px; padding-top: 24px; border-top: 1px solid var(--paper-200); font-size: 13px; color: var(--paper-500); }
.footer p { margin: 0; }

/* responsive */
@media (max-width: 720px) {
  .page { padding: 32px 16px 64px; }
  .hero h1 { font-size: 40px; }
  .versions { grid-template-columns: 1fr; }
}