/* ============================================================
   OBSPS Public Stylesheet — Contemporary Innovations Journal
   ============================================================ */

:root {
  --primary:    #29166F;
  --primary-lt: #3C20A3;
  --accent:     #0093DD;
  --bg:         #ffffff;
  --bg-light:   #DEDEDC;
  --bg-alt:     #eef2f7;
  --text:       #1a1a2e;
  --text-muted: #6b7280;
  --border:     #d1dbe8;
  --radius:     6px;
  --shadow:     0 2px 12px rgba(26,58,92,.10);
  --font-body:  'Merriweather', Georgia, serif;
  --font-ui:    'Inter', system-ui, sans-serif;
  --max-w:      1180px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: var(--font-body); font-size: 1rem; line-height: 1.75; color: var(--text); background: var(--bg); }
a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--accent); text-decoration: underline; }
img { max-width: 100%; height: auto; display: block; }

/* ── Layout ──────────────────────────────────────────────── */
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 1.5rem; }

/* ── Site Header ─────────────────────────────────────────── */
.site-header {
  background: var(--primary);
  color: #fff;
  padding: .9rem 0;
  position: sticky; top: 0; z-index: 100;
  box-shadow: 0 2px 8px rgba(0,0,0,.2);
}
.site-header .container { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: .75rem; }
.site-logo { color: #fff; font-family: var(--font-ui); font-weight: 700; font-size: 1.1rem; letter-spacing: .03em; text-decoration: none; }
.site-nav { display: flex; gap: 1.5rem; }
.site-nav a { color: rgba(255,255,255,.85); font-family: var(--font-ui); font-size: .9rem; transition: color .2s; text-decoration: none; }
.site-nav a:hover { color: var(--accent); }

/* ── Breadcrumb ──────────────────────────────────────────── */
.breadcrumb { font-family: var(--font-ui); font-size: .82rem; color: var(--text-muted); padding: 1rem 0; }
.breadcrumb a { color: var(--primary); }

/* ── Book Page Grid ──────────────────────────────────────── */
.book-page { padding: 2rem 0 4rem; }
.book-grid { display: grid; grid-template-columns: 260px 1fr; gap: 2.5rem; align-items: start; }
@media (max-width: 768px) { .book-grid { grid-template-columns: 1fr; } }

/* ── Sidebar ─────────────────────────────────────────────── */
.book-sidebar { position: sticky; top: 90px; }
.cover-card { background: var(--bg-light); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; margin-bottom: 1.25rem; }
.book-cover { width: 100%; }
.cover-placeholder { background: var(--primary); color: #fff; text-align: center; padding: 3.5rem 1rem; font-family: var(--font-ui); font-size: 2.5rem; font-weight: 700; letter-spacing: .1em; }

.download-section { background: var(--bg-light); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.25rem; margin-bottom: 1.25rem; }
.download-section h3 { font-family: var(--font-ui); font-size: .9rem; text-transform: uppercase; letter-spacing: .08em; color: var(--primary); margin-bottom: 1rem; }
.download-buttons { display: flex; flex-direction: column; gap: .5rem; }
.download-btn { display: flex; align-items: center; gap: .5rem; padding: .55rem 1rem; border-radius: var(--radius); font-family: var(--font-ui); font-size: .875rem; font-weight: 600; text-decoration: none; transition: opacity .2s, transform .15s; color: #fff; }
.download-btn:hover { opacity: .9; transform: translateX(2px); }
.btn-pdf  { background: #c0392b; }
.btn-epub { background: #16a085; }
.btn-xml  { background: #2980b9; }
.btn-html { background: #8e44ad; }
.btn-mobi { background: #d35400; }
.btn-outline { display: block; text-align: center; border: 1px solid var(--primary); border-radius: var(--radius); padding: .5rem 1rem; font-family: var(--font-ui); font-size: .85rem; color: var(--primary); margin-top: .75rem; transition: background .2s; }
.btn-outline:hover { background: var(--primary); color: #fff; text-decoration: none; }

.book-meta-box { background: var(--bg-light); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.25rem; }
.book-meta-box dl { font-family: var(--font-ui); font-size: .82rem; }
.book-meta-box dt { color: var(--text-muted); font-weight: 600; margin-top: .6rem; }
.book-meta-box dd { color: var(--text); word-break: break-all; }

/* ── Main Content ────────────────────────────────────────── */
.book-header { border-bottom: 1px solid var(--border); padding-bottom: 1.5rem; margin-bottom: 1.75rem; }
.book-badge { display: inline-block; background: #e6f3e6; color: #256025; font-family: var(--font-ui); font-size: .72rem; font-weight: 700; text-transform: uppercase; letter-spacing: .1em; padding: .25em .7em; border-radius: 30px; margin-bottom: .75rem; }
.book-title { font-size: 1.9rem; font-weight: 700; color: var(--primary); line-height: 1.25; margin-bottom: .4rem; }
.book-subtitle { font-size: 1.2rem; font-weight: 400; color: var(--primary-lt); margin-bottom: .75rem; }
.book-authors { display: flex; flex-wrap: wrap; gap: .4rem 1rem; margin: .75rem 0; }
.author-item { font-family: var(--font-ui); font-size: .9rem; color: var(--text); }
.affiliation { display: block; font-size: .78rem; color: var(--text-muted); }
.orcid-link { font-size: .78rem; }
.doi-link { font-family: var(--font-ui); font-size: .85rem; color: var(--text-muted); margin-top: .5rem; }
.doi-link a { color: var(--primary); }

/* ── Abstract & Keywords ─────────────────────────────────── */
.abstract { background: var(--bg-alt); border-left: 4px solid var(--primary); border-radius: 0 var(--radius) var(--radius) 0; padding: 1.25rem 1.5rem; margin: 1.5rem 0; }
.abstract h3 { font-family: var(--font-ui); font-size: .8rem; text-transform: uppercase; letter-spacing: .12em; color: var(--primary); margin-bottom: .75rem; }
.abstract p { font-size: .95rem; margin: 0; }
.keywords { font-family: var(--font-ui); font-size: .85rem; color: var(--text-muted); margin: .5rem 0 1.5rem; }

/* ── Book Body ───────────────────────────────────────────── */
.book-body { font-size: 1rem; line-height: 1.8; }
.book-body h1 { font-size: 1.6rem; color: var(--primary); margin: 2rem 0 .75rem; }
.book-body h2 { font-size: 1.35rem; color: var(--primary); border-bottom: 1px solid var(--border); padding-bottom: .35rem; margin: 1.75rem 0 .75rem; }
.book-body h3 { font-size: 1.15rem; color: var(--primary-lt); margin: 1.5rem 0 .5rem; }
.book-body h4 { font-size: 1rem; color: var(--primary-lt); margin: 1.25rem 0 .4rem; }
.book-body p  { margin: 0 0 .9rem; }
.book-body ul, .book-body ol { margin: .75rem 0 .75rem 1.75rem; }
.book-body li { margin-bottom: .35rem; }
.book-body blockquote { border-left: 4px solid var(--accent); margin: 1.25rem 0 1.25rem 1rem; padding: .75rem 1.25rem; background: var(--bg-light); font-style: italic; color: #444; border-radius: 0 var(--radius) var(--radius) 0; }
.book-body figure { margin: 1.5rem 0; text-align: center; }
.book-body figcaption { font-family: var(--font-ui); font-size: .82rem; color: var(--text-muted); margin-top: .5rem; }
.book-body .book-table { width: 100%; border-collapse: collapse; margin: 1.25rem 0; font-size: .9rem; }
.book-body .book-table th { background: var(--primary); color: #fff; padding: .55rem .75rem; text-align: left; }
.book-body .book-table td { border: 1px solid var(--border); padding: .45rem .75rem; }
.book-body .book-table tr:nth-child(even) td { background: var(--bg-light); }
.book-body sup, .book-body sub { font-size: .7em; }
.book-body pre { background: #1e1e2e; color: #cdd6f4; border-radius: var(--radius); padding: 1rem 1.25rem; overflow-x: auto; font-size: .85rem; margin: 1rem 0; }
.book-body code { font-family: 'Courier New', monospace; background: var(--bg-alt); padding: .1em .35em; border-radius: 3px; font-size: .88em; }

/* ── Citation Box ────────────────────────────────────────── */
.citation-box { background: var(--bg-light); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.5rem; margin-top: 2.5rem; }
.citation-box h3 { font-family: var(--font-ui); font-size: .85rem; text-transform: uppercase; letter-spacing: .1em; color: var(--primary); margin-bottom: 1rem; }
.citation-tabs { display: flex; flex-wrap: wrap; gap: .35rem; margin-bottom: 1rem; }
.cite-tab { font-family: var(--font-ui); font-size: .78rem; padding: .3em .85em; border: 1px solid var(--border); border-radius: 30px; background: var(--bg); color: var(--text-muted); cursor: pointer; transition: all .2s; }
.cite-tab.active, .cite-tab:hover { background: var(--primary); color: #fff; border-color: var(--primary); }
.cite-entry p { font-family: var(--font-ui); font-size: .87rem; line-height: 1.6; padding: .75rem 1rem; background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius); margin-bottom: .6rem; }
.copy-btn { font-family: var(--font-ui); font-size: .78rem; padding: .3em .85em; border: 1px solid var(--primary); border-radius: var(--radius); background: transparent; color: var(--primary); cursor: pointer; transition: all .2s; }
.copy-btn:hover, .copy-btn.copied { background: var(--primary); color: #fff; }

/* ── Footer ──────────────────────────────────────────────── */
.site-footer { background: var(--primary); color: rgba(255,255,255,.75); padding: 2rem 0; margin-top: 4rem; font-family: var(--font-ui); font-size: .84rem; text-align: center; }
.site-footer a { color: rgba(255,255,255,.85); }
.site-footer p + p { margin-top: .5rem; }

/* ── Books listing page ──────────────────────────────────── */
.books-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 1.5rem; padding: 2rem 0; }
.book-card { border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; transition: box-shadow .2s, transform .2s; background: var(--bg); }
.book-card:hover { box-shadow: var(--shadow); transform: translateY(-3px); }
.book-card-cover { background: var(--primary); height: 180px; display: flex; align-items: center; justify-content: center; color: #fff; font-size: 2rem; font-family: var(--font-ui); font-weight: 700; }
.book-card-cover img { width: 100%; height: 180px; object-fit: cover; }
.book-card-body { padding: 1rem; }
.book-card-title { font-size: .95rem; font-weight: 700; color: var(--primary); margin-bottom: .4rem; line-height: 1.3; }
.book-card-authors { font-family: var(--font-ui); font-size: .78rem; color: var(--text-muted); }
.book-card-badge { display: inline-block; font-family: var(--font-ui); font-size: .68rem; background: #e6f3e6; color: #256025; padding: .15em .5em; border-radius: 3px; margin-bottom: .4rem; }

/* ── Page hero ───────────────────────────────────────────── */
.page-hero { background: linear-gradient(135deg, var(--primary) 0%, var(--primary-lt) 100%); color: #fff; padding: 3rem 0; text-align: center; margin-bottom: 2rem; }
.page-hero h1 { font-size: 2.2rem; margin-bottom: .5rem; }
.page-hero p { opacity: .85; font-family: var(--font-ui); }

/* ── Responsive ──────────────────────────────────────────── */
@media (max-width: 600px) {
  .book-title { font-size: 1.4rem; }
  .site-nav { gap: .75rem; }
  .download-buttons { flex-direction: row; flex-wrap: wrap; }
  .download-btn { flex: 1 1 calc(50% - .25rem); justify-content: center; }
}