/* =====================
   TOKENS
   ===================== */
:root {
    --ink:        #1a1a2e;
    --ink-light:  #4a4a6a;
    --paper:      #f8f7f4;
    --paper-dark: #eeecea;
    --accent:     #2d6a4f;
    --accent-mid: #40916c;
    --accent-light:#d8f3dc;
    --gold:       #b5882a;
    --white:      #ffffff;
    --border:     #dddbd6;
    --shadow:     0 2px 12px rgba(26,26,46,0.08);
    --shadow-lg:  0 8px 32px rgba(26,26,46,0.14);
    --radius:     10px;
    --font-display: 'Playfair Display', Georgia, serif;
    --font-body:    'Inter', system-ui, sans-serif;
}

/* =====================
   RESET & BASE
   ===================== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
    font-family: var(--font-body);
    background: var(--paper);
    color: var(--ink);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

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

img { max-width: 100%; }

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* =====================
   HEADER
   ===================== */
.site-header {
    background: var(--ink);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.site-logo {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    color: var(--white) !important;
    font-family: var(--font-display);
    font-size: 1.4rem;
    font-weight: 700;
    letter-spacing: 0.01em;
}

.logo-icon { font-size: 1.5rem; }

.site-nav { display: flex; gap: 1.5rem; }

.site-nav a {
    color: rgba(255,255,255,0.75);
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.2s;
    letter-spacing: 0.02em;
}

.site-nav a:hover { color: var(--white); }

/* =====================
   MAIN
   ===================== */
.site-main { flex: 1; }

/* =====================
   HERO
   ===================== */
.hero {
    background: linear-gradient(135deg, var(--ink) 0%, #2d2d4e 100%);
    color: var(--white);
    padding: 4rem 0 3rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero-content { position: relative; z-index: 1; }

.hero-eyebrow {
    display: inline-block;
    background: var(--accent-light);
    color: var(--accent);
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    padding: 0.3rem 0.9rem;
    border-radius: 2rem;
    margin-bottom: 1.2rem;
}

.hero h1 {
    font-family: var(--font-display);
    font-size: clamp(2rem, 5vw, 3.2rem);
    font-weight: 700;
    line-height: 1.15;
    margin-bottom: 1rem;
}

.hero p {
    color: rgba(255,255,255,0.7);
    font-size: 1.05rem;
    max-width: 520px;
    margin: 0 auto;
}

/* =====================
   SEARCH BAR
   ===================== */
.search-bar-wrap {
    background: var(--white);
    border-bottom: 1px solid var(--border);
    padding: 0.9rem 0;
    position: sticky;
    top: 57px;
    z-index: 91;
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}

.search-input-wrap {
    display: flex;
    align-items: center;
    background: var(--paper);
    border: 1.5px solid var(--border);
    border-radius: 2rem;
    padding: 0.45rem 1rem;
    gap: 0.5rem;
    transition: border-color 0.18s, box-shadow 0.18s;
    max-width: 560px;
}

.search-input-wrap:focus-within {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-light);
}

.search-icon {
    font-size: 1rem;
    flex-shrink: 0;
    opacity: 0.6;
}

.search-input {
    flex: 1;
    border: none;
    background: transparent;
    font-size: 0.92rem;
    font-family: var(--font-body);
    color: var(--ink);
    outline: none;
    padding: 0;
}

.search-input::placeholder {
    color: var(--ink-light);
    opacity: 0.7;
}

.search-clear {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--ink-light);
    font-size: 0.8rem;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 1.4rem;
    height: 1.4rem;
    border-radius: 50%;
    transition: background 0.15s, color 0.15s;
    flex-shrink: 0;
}

.search-clear:hover {
    background: var(--border);
    color: var(--ink);
}

/* =====================
   BOOKS FILTER BAR
   ===================== */
.filter-bar {
    background: var(--white);
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
    position: sticky;
    top: 114px;
    z-index: 90;
}

.filter-bar .container {
    display: flex;
    gap: 0.6rem;
    flex-wrap: wrap;
    align-items: center;
}

.filter-label {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--ink-light);
    letter-spacing: 0.05em;
    text-transform: uppercase;
    margin-right: 0.4rem;
}

.filter-btn {
    background: var(--paper);
    border: 1.5px solid var(--border);
    color: var(--ink-light);
    padding: 0.35rem 0.9rem;
    border-radius: 2rem;
    font-size: 0.82rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.18s;
    font-family: var(--font-body);
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--accent);
    border-color: var(--accent);
    color: var(--white);
}

/* =====================
   STUDIES GRID
   ===================== */
.studies-section {
    padding: 2.5rem 0 4rem;
}

.section-heading {
    font-family: var(--font-display);
    font-size: 1.4rem;
    color: var(--ink);
    margin-bottom: 1.5rem;
    padding-bottom: 0.6rem;
    border-bottom: 2px solid var(--accent-light);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.studies-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.4rem;
}

.study-card {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
    transition: transform 0.2s, box-shadow 0.2s;
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
    cursor: pointer;
}

.study-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent-mid);
}

.study-card-book {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    background: var(--accent-light);
    padding: 0.2rem 0.6rem;
    border-radius: 2rem;
    width: fit-content;
}

.study-card h3 {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--ink);
    line-height: 1.3;
}

.study-card-author {
    font-size: 0.85rem;
    color: var(--ink-light);
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.study-card-abstract {
    font-size: 0.82rem;
    color: var(--ink-light);
    line-height: 1.55;
    margin: 0.45rem 0 0;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.study-card-pages {
    font-size: 0.78rem;
    color: var(--gold);
    font-weight: 600;
    letter-spacing: 0.04em;
    margin-top: auto;
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.read-btn {
    display: block;
    text-align: center;
    background: var(--accent);
    color: var(--white);
    padding: 0.6rem 1rem;
    border-radius: var(--radius);
    font-size: 0.85rem;
    font-weight: 600;
    transition: background 0.2s;
    margin-top: 0.4rem;
}

.read-btn:hover {
    background: var(--accent-mid);
    color: var(--white);
}

/* =====================
   EMPTY STATE
   ===================== */
.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--ink-light);
}

.empty-state .empty-icon { font-size: 3rem; margin-bottom: 1rem; }
.empty-state h3 { font-family: var(--font-display); font-size: 1.3rem; margin-bottom: 0.5rem; color: var(--ink); }
.empty-state p { font-size: 0.9rem; }

/* =====================
   FOOTER
   ===================== */
.site-footer {
    background: var(--ink);
    color: rgba(255,255,255,0.45);
    text-align: center;
    padding: 1.2rem 0;
    font-size: 0.82rem;
}

/* =====================
   ADMIN LAYOUT
   ===================== */
.admin-layout {
    display: grid;
    grid-template-columns: 220px 1fr;
    min-height: calc(100vh - 57px);
}

.admin-sidebar {
    background: var(--ink);
    padding: 1.5rem 0;
}

.admin-sidebar-title {
    color: rgba(255,255,255,0.4);
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    padding: 0 1.2rem;
    margin-bottom: 0.8rem;
}

.admin-sidebar a {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.65rem 1.2rem;
    color: rgba(255,255,255,0.65);
    font-size: 0.88rem;
    font-weight: 500;
    transition: all 0.18s;
    border-left: 3px solid transparent;
}

.admin-sidebar a:hover,
.admin-sidebar a.active {
    color: var(--white);
    background: rgba(255,255,255,0.06);
    border-left-color: var(--accent-mid);
}

.admin-sidebar .divider {
    height: 1px;
    background: rgba(255,255,255,0.08);
    margin: 0.8rem 1.2rem;
}

.admin-content {
    padding: 2rem 2.5rem;
    background: var(--paper);
}

.admin-page-title {
    font-family: var(--font-display);
    font-size: 1.6rem;
    color: var(--ink);
    margin-bottom: 1.5rem;
    padding-bottom: 0.7rem;
    border-bottom: 2px solid var(--border);
}

/* =====================
   CARDS / PANELS
   ===================== */
.panel {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
    margin-bottom: 1.5rem;
}

.panel-title {
    font-family: var(--font-display);
    font-size: 1.05rem;
    color: var(--ink);
    margin-bottom: 1.2rem;
    font-weight: 600;
}

/* =====================
   FORMS
   ===================== */
.form-group {
    margin-bottom: 1.2rem;
}

.form-group label {
    display: block;
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--ink-light);
    margin-bottom: 0.4rem;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.65rem 0.9rem;
    border: 1.5px solid var(--border);
    border-radius: var(--radius);
    font-family: var(--font-body);
    font-size: 0.95rem;
    color: var(--ink);
    background: var(--paper);
    transition: border-color 0.2s;
    outline: none;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: var(--accent);
    background: var(--white);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

/* =====================
   BUTTONS
   ===================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.6rem 1.2rem;
    border-radius: var(--radius);
    font-family: var(--font-body);
    font-size: 0.88rem;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: all 0.18s;
    text-decoration: none;
}

.btn-primary {
    background: var(--accent);
    color: var(--white);
}
.btn-primary:hover { background: var(--accent-mid); color: var(--white); }

.btn-danger {
    background: #e74c3c;
    color: var(--white);
}
.btn-danger:hover { background: #c0392b; color: var(--white); }

.btn-secondary {
    background: var(--paper-dark);
    color: var(--ink);
    border: 1.5px solid var(--border);
}
.btn-secondary:hover { background: var(--border); }

.btn-sm { padding: 0.35rem 0.75rem; font-size: 0.8rem; }

/* =====================
   TABLE
   ===================== */
.data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.88rem;
}

.data-table th {
    background: var(--paper-dark);
    color: var(--ink-light);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    padding: 0.7rem 1rem;
    text-align: left;
    border-bottom: 2px solid var(--border);
}

.data-table td {
    padding: 0.8rem 1rem;
    border-bottom: 1px solid var(--border);
    color: var(--ink);
    vertical-align: middle;
}

.data-table tr:last-child td { border-bottom: none; }
.data-table tr:hover td { background: var(--paper); }

/* =====================
   ALERTS
   ===================== */
.alert {
    padding: 0.8rem 1rem;
    border-radius: var(--radius);
    font-size: 0.88rem;
    margin-bottom: 1rem;
    font-weight: 500;
}

.alert-success { background: #d4edda; color: #155724; border: 1px solid #c3e6cb; }
.alert-error   { background: #f8d7da; color: #721c24; border: 1px solid #f5c6cb; }

/* =====================
   BADGE
   ===================== */
.badge {
    display: inline-block;
    padding: 0.15rem 0.55rem;
    border-radius: 2rem;
    font-size: 0.72rem;
    font-weight: 600;
}

.badge-green { background: var(--accent-light); color: var(--accent); }
.badge-gold  { background: #fef3cd; color: #856404; }

/* =====================
   PDF VIEWER PAGE
   ===================== */
.viewer-page {
    display: flex;
    flex-direction: column;
    height: calc(100vh - 57px);
}

.viewer-toolbar {
    background: var(--white);
    border-bottom: 1px solid var(--border);
    padding: 0.7rem 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
    box-shadow: var(--shadow);
}

.viewer-toolbar h2 {
    font-family: var(--font-display);
    font-size: 1rem;
    color: var(--ink);
    font-weight: 600;
    flex: 1;
}

.viewer-meta {
    font-size: 0.78rem;
    color: var(--ink-light);
    display: flex;
    align-items: center;
    gap: 0.3rem;
}

.viewer-page-info {
    font-size: 0.8rem;
    color: var(--ink-light);
    font-weight: 500;
    background: var(--paper);
    padding: 0.3rem 0.75rem;
    border-radius: 2rem;
    border: 1px solid var(--border);
}

.viewer-nav {
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.viewer-nav button {
    background: var(--paper);
    border: 1.5px solid var(--border);
    color: var(--ink);
    padding: 0.3rem 0.7rem;
    border-radius: var(--radius);
    cursor: pointer;
    font-size: 0.85rem;
    transition: all 0.18s;
    font-family: var(--font-body);
}

.viewer-nav button:hover:not(:disabled) {
    background: var(--accent);
    border-color: var(--accent);
    color: var(--white);
}

.viewer-nav button:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.viewer-canvas-wrap {
    flex: 1;
    overflow-y: auto;
    background: #fdfdfd;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 1.5rem;
    gap: 1rem;
}

#pdf-canvas {
    display: block;
    box-shadow: 0 4px 24px rgba(0,0,0,0.35);
    background: white;
    max-width: 100%;
}

.viewer-loading {
    color: rgba(255,255,255,0.7);
    font-size: 0.9rem;
    padding: 2rem;
    text-align: center;
}

/* =====================
   STATS CARDS (Admin Dashboard)
   ===================== */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.2rem 1.5rem;
    box-shadow: var(--shadow);
}

.stat-card-label {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--ink-light);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 0.4rem;
}

.stat-card-value {
    font-family: var(--font-display);
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent);
}

/* =====================
   RESPONSIVE
   ===================== */
@media (max-width: 768px) {
    .admin-layout { grid-template-columns: 1fr; }
    .admin-sidebar { display: flex; flex-wrap: wrap; gap: 0.3rem; padding: 0.8rem; }
    .admin-sidebar a { padding: 0.4rem 0.8rem; border-left: none; border-radius: var(--radius); font-size: 0.8rem; }
    .form-row { grid-template-columns: 1fr; }
    .studies-grid { grid-template-columns: 1fr; }
    .viewer-toolbar { flex-direction: column; align-items: flex-start; }
}