/* ============================================================
   sleeper.css — dark "Citizen Sleeper" design system for subpages
   Shared by the fun/* pages. Matches index.html / now.html.
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500;700&display=swap');

:root {
    --bg:    #0e1416;
    --bg2:   #131c1f;
    --bg3:   #18211f;
    --line:  rgba(231, 210, 170, 0.14);
    --line2: rgba(231, 210, 170, 0.28);
    --text:  #e8e2d4;
    --dim:   #7d8a8a;
    --amber: #e3a94e;
    --teal:  #67c0b4;
    --coral: #e07b66;
    /* atmosphere (baked from the dev-kit defaults) */
    --star-opacity: 0.9;
    --star-size: 440px;
    --star-speed: 120s;
    --lamp-min: 0.43;
    --lamp-max: 0.95;
    --lamp-speed: 11s;
    --vignette: 0.5;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0; background: var(--bg); color: var(--text);
    font-family: 'Inter', system-ui, sans-serif; font-size: 1.05rem; line-height: 1.75;
    -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility;
}
a { color: var(--teal); text-decoration: none; }
a:hover { color: var(--amber); }

/* ============ atmosphere ============ */
.atmos { position: fixed; inset: 0; z-index: 0; pointer-events: none; overflow: hidden;
    background: radial-gradient(125% 95% at 50% 45%, transparent 52%, rgba(0,0,0,var(--vignette)) 100%); }
.atmos .stars {
    position: absolute; inset: 0;
    background-image:
        radial-gradient(1.6px 1.6px at 20% 30%, rgba(232,226,212,0.95), transparent),
        radial-gradient(1.3px 1.3px at 60% 70%, rgba(232,226,212,0.75), transparent),
        radial-gradient(2px 2px   at 80% 18%, rgba(232,226,212,0.9), transparent),
        radial-gradient(1.2px 1.2px at 40% 82%, rgba(232,226,212,0.6), transparent),
        radial-gradient(1.4px 1.4px at 92% 58%, rgba(232,226,212,0.78), transparent),
        radial-gradient(1.2px 1.2px at 10% 62%, rgba(232,226,212,0.6), transparent),
        radial-gradient(2px 2px   at 33% 12%, rgba(232,226,212,0.85), transparent),
        radial-gradient(1.3px 1.3px at 74% 88%, rgba(232,226,212,0.65), transparent),
        radial-gradient(1.2px 1.2px at 50% 48%, rgba(232,226,212,0.6), transparent),
        radial-gradient(1.5px 1.5px at 15% 16%, rgba(232,226,212,0.8), transparent),
        radial-gradient(1.2px 1.2px at 68% 38%, rgba(232,226,212,0.6), transparent),
        radial-gradient(1.3px 1.3px at 88% 80%, rgba(232,226,212,0.65), transparent);
    background-repeat: repeat; background-size: var(--star-size) var(--star-size);
    opacity: var(--star-opacity); animation: drift var(--star-speed) linear infinite; }
.atmos .lamp { position: absolute; inset: 0;
    background:
        radial-gradient(780px 580px at 20% 26%, rgba(227,169,78,0.17), transparent 62%),
        radial-gradient(700px 580px at 84% 76%, rgba(224,123,102,0.14), transparent 62%);
    animation: breathe var(--lamp-speed) ease-in-out infinite; }
@keyframes drift { to { background-position: 0 calc(-1 * var(--star-size)); } }
@keyframes breathe { 0%,100% { opacity: var(--lamp-min); } 50% { opacity: var(--lamp-max); } }

/* ============ page + topbar ============ */
.page { position: relative; z-index: 1; max-width: 680px; margin: 0 auto; padding: 0 28px; }
.topbar { display: flex; align-items: center; justify-content: space-between;
    padding: 30px 0; border-bottom: 1px solid var(--line); }
.wordmark { font-weight: 700; letter-spacing: -0.01em; color: var(--text); }
.wordmark:hover { color: var(--amber); }
.backlink { font-family: 'JetBrains Mono', monospace; font-size: 0.82rem; color: var(--dim); }
.backlink:hover { color: var(--amber); }
.backlink .arr { display: inline-block; transition: transform .18s ease; }
.backlink:hover .arr { transform: translateX(-3px); }

.pagehead { margin: 6vh 0 5vh; }
.pagehead .eyebrow { font-family: 'JetBrains Mono', monospace; font-size: 0.72rem; letter-spacing: 0.22em;
    text-transform: uppercase; color: var(--coral); margin: 0 0 14px; }
.pagehead h1 { font-size: clamp(2.2rem, 5.5vw, 3.2rem); font-weight: 700; letter-spacing: -0.025em; margin: 0; }
.pagehead .stamp { font-family: 'JetBrains Mono', monospace; font-size: 0.76rem; color: var(--dim);
    letter-spacing: 0.08em; margin-top: 14px; }

/* ============ prose ============ */
.prose { position: relative; z-index: 1; padding-bottom: 8vh; }
.prose p { margin: 0 0 1.1em; }
.muted { color: var(--dim); }
.prose h2 { font-size: clamp(1.5rem, 3.4vw, 1.9rem); font-weight: 600; letter-spacing: -0.02em; margin: 2em 0 0.6em; }
.prose h3 { font-family: 'JetBrains Mono', monospace; font-size: 0.95rem; letter-spacing: 0.06em;
    text-transform: uppercase; color: var(--teal); margin: 1.8em 0 0.6em; }
.prose ul { padding-left: 1.2em; margin: 0 0 1.1em; }
.prose li { margin-bottom: 0.4em; }
.prose li::marker { color: var(--coral); }

/* ============ verse / poem ============ */
.verse { position: relative; z-index: 1; margin: 4vh auto 8vh; max-width: 460px;
    font-family: 'Inter', sans-serif; font-style: italic; color: var(--amber); line-height: 2; font-size: 1.18rem; }
.verse p { margin-bottom: 1.8em; }
.verse.centered { text-align: center; }

/* ============ figure ============ */
.figure { position: relative; z-index: 1; margin: 4vh 0 8vh; }
.figure img { max-width: 100%; height: auto; border-radius: 12px; border: 1px solid var(--line2);
    box-shadow: 0 24px 60px rgba(0,0,0,0.55); }

/* ============ book flip cards ============ */
.book-card { perspective: 1200px; margin: 22px 0; cursor: pointer; height: 200px; }
.book-card-inner { position: relative; width: 100%; height: 100%;
    transition: transform 0.6s cubic-bezier(0.4, 0.2, 0.2, 1); transform-style: preserve-3d; }
.book-card.flipped .book-card-inner { transform: rotateY(180deg); }
.book-card-front, .book-card-back { position: absolute; inset: 0; backface-visibility: hidden;
    border-radius: 14px; border: 1px solid var(--line); background: var(--bg2);
    box-shadow: 0 14px 34px rgba(0,0,0,0.4); }
.book-card-front { display: flex; align-items: center; gap: 22px; padding: 22px; }
.book-cover-image img { width: 110px; height: 160px; object-fit: cover; border-radius: 8px;
    box-shadow: 0 8px 20px rgba(0,0,0,0.5); }
.book-info .book-title { font-size: 1.3rem; font-weight: 600; line-height: 1.2; color: var(--text); }
.book-info .book-author { color: var(--dim); margin: 4px 0 14px; }
.flip-hint { font-family: 'JetBrains Mono', monospace; font-size: 0.78rem; color: var(--teal); }
.book-card-back { transform: rotateY(180deg); display: flex; align-items: center; padding: 26px 30px;
    background: var(--bg3); border-left: 3px solid var(--coral); }
.book-card-back p { margin: 0; font-size: 1rem; line-height: 1.65; color: var(--text); }

/* ============ collapsible ============ */
.collapsible-section { margin: 4vh 0; }
.collapsible-header { background: var(--bg2); border: 1px solid var(--line); border-left: 3px solid var(--coral);
    border-radius: 12px; padding: 22px 24px; cursor: pointer; transition: all 0.2s ease; }
.collapsible-header:hover { transform: translateY(-2px); box-shadow: 0 14px 30px rgba(0,0,0,0.4); border-color: var(--line2); }
.collapsible-header h3 { margin: 0; font-size: 1.2rem; font-weight: 600; color: var(--text);
    font-family: 'Inter', sans-serif; text-transform: none; letter-spacing: -0.01em; }
.collapsible-hint { font-family: 'JetBrains Mono', monospace; font-size: 0.76rem; color: var(--dim); margin-top: 7px; }
.collapsible-content { max-height: 0; overflow: hidden; transition: max-height 0.5s ease-out; }
.collapsible-content.active { max-height: 2000px; }
.collapsible-content-inner { background: var(--bg3); border: 1px solid var(--line); border-radius: 12px;
    padding: 6px 26px 22px; margin-top: 12px; }

/* ============ reveal + responsive ============ */
.reveal { opacity: 0; transform: translateY(16px); transition: opacity .7s ease, transform .7s ease; }
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
    .reveal { opacity: 1; transform: none; transition: none; }
    .atmos .stars, .atmos .lamp { animation: none; }
    html { scroll-behavior: auto; }
}

@media (max-width: 540px) {
    .book-card { height: auto; }
    .book-card-inner { transform: none !important; }
    .book-card-front, .book-card-back { position: static; backface-visibility: visible; transform: none; }
    .book-card-back { margin-top: 12px; }
    .flip-hint { display: none; }
}