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

:root {
  --bg:           #0d1117;
  --bg-card:      #161b22;
  --bg-card-hover:#1c2128;
  --border:       #30363d;
  --primary:      #4f8ef7;
  --primary-dark: #3a6fd8;
  --success:      #3fb950;
  --danger:       #f85149;
  --warning:      #d29922;
  --text:         #e6edf3;
  --text-muted:   #8b949e;
  --radius:       10px;
  --shadow:       0 4px 24px rgba(0,0,0,0.4);
  --font:         'Inter', sans-serif;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  overflow-x: hidden;
}

/* ===== HEADER ===== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(13, 17, 23, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
}

.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  height: 64px;
  display: flex;
  align-items: center;
  gap: 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.logo-icon { font-size: 1.6rem; }
.logo-text {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.3px;
}
.logo-badge {
  font-size: 0.65rem;
  font-weight: 600;
  background: linear-gradient(135deg, #4f8ef7, #9b59f7);
  color: #fff;
  padding: 2px 8px;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* ===== NAV TABS ===== */
.nav-tabs {
  display: flex;
  gap: 4px;
  flex: 1;
  justify-content: center;
}

.tab-btn {
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--radius);
  color: var(--text-muted);
  cursor: pointer;
  font-family: var(--font);
  font-size: 0.875rem;
  font-weight: 500;
  padding: 8px 20px;
  transition: all 0.2s ease;
}
.tab-btn:hover {
  color: var(--text);
  background: var(--bg-card-hover);
  border-color: var(--border);
}
.tab-btn.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}

/* ===== STATUS INDICATOR ===== */
.status-indicator {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8rem;
  color: var(--text-muted);
  flex-shrink: 0;
  cursor: pointer;
}
.dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--warning);
  animation: pulse 2s infinite;
}
.dot.online  { background: var(--success); }
.dot.offline { background: var(--danger); animation: none; }

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

/* ===== MAIN ===== */
.main {
  max-width: 1280px;
  margin: 0 auto;
  padding: 32px 24px;
}

/* ===== TAB CONTENT ===== */
.tab-content { display: none; }
.tab-content.active { display: block; animation: fadeIn 0.3s ease; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ===== PAGE TITLE ===== */
.page-title {
  margin-bottom: 28px;
}
.page-title h1 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 6px;
}
.page-title p {
  color: var(--text-muted);
  font-size: 0.9rem;
}
.page-title strong { color: var(--primary); }
.page-title em { color: var(--success); font-style: normal; }

/* ===== CARD GRID ===== */
.card-grid {
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 20px;
  align-items: start;
}

@media (max-width: 900px) {
  .card-grid { grid-template-columns: 1fr; }
}

/* ===== CARD ===== */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: border-color 0.2s;
}
.card:hover { border-color: #484f58; }
.card.wide { grid-column: auto; }

.card-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 18px;
  color: var(--text);
}
.card-title-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 18px;
}
.card-title-row .card-title { margin-bottom: 0; }

/* ===== FORM ===== */
.form { display: flex; flex-direction: column; gap: 14px; }

.form-group { display: flex; flex-direction: column; gap: 6px; }
.form-group label {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.form-group input,
.form-group select,
.form-group textarea {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  font-family: var(--font);
  font-size: 0.9rem;
  padding: 10px 12px;
  outline: none;
  transition: border-color 0.2s;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--primary);
}
.form-group select { cursor: pointer; }
.form-group input[type="file"] {
  padding: 8px;
  cursor: pointer;
}
.file-hint {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.divider {
  height: 1px;
  background: var(--border);
  margin: 20px 0;
}

/* ===== BUTTONS ===== */
.btn {
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-family: var(--font);
  font-size: 0.875rem;
  font-weight: 600;
  padding: 10px 20px;
  transition: all 0.2s ease;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}
.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}
.btn-primary {
  background: var(--primary);
  color: #fff;
  width: 100%;
}
.btn-primary:hover:not(:disabled) { background: var(--primary-dark); transform: translateY(-1px); }

.btn-success {
  background: var(--success);
  color: #fff;
  width: 100%;
}
.btn-success:hover:not(:disabled) { background: #2ea043; transform: translateY(-1px); }

.btn-danger {
  background: var(--danger);
  color: #fff;
  font-size: 0.75rem;
  padding: 5px 12px;
}
.btn-danger:hover:not(:disabled) { background: #da3633; }

.btn-outline {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-muted);
}
.btn-outline:hover { border-color: var(--primary); color: var(--primary); }

.btn-sm { font-size: 0.8rem; padding: 6px 14px; }

/* ===== DATA LIST ===== */
.data-list { display: flex; flex-direction: column; gap: 10px; max-height: 520px; overflow-y: auto; }
.data-list::-webkit-scrollbar { width: 4px; }
.data-list::-webkit-scrollbar-track { background: transparent; }
.data-list::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }

/* ===== DATA ITEM ===== */
.data-item {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  transition: border-color 0.2s;
  animation: fadeIn 0.3s ease;
}
.data-item:hover { border-color: var(--primary); }

.data-item-info { flex: 1; min-width: 0; }
.data-item-title {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.data-item-sub {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 3px;
}
.data-item-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

/* ===== BADGES ===== */
.badge {
  font-size: 0.7rem;
  font-weight: 600;
  padding: 3px 9px;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: 0.4px;
}
.badge-blue    { background: rgba(79,142,247,0.15); color: var(--primary); }
.badge-green   { background: rgba(63,185,80,0.15);  color: var(--success); }
.badge-yellow  { background: rgba(210,153,34,0.15); color: var(--warning); }
.badge-red     { background: rgba(248,81,73,0.15);  color: var(--danger); }

/* ===== BOOK COVER THUMB ===== */
.book-cover {
  width: 40px;
  height: 52px;
  object-fit: cover;
  border-radius: 4px;
  border: 1px solid var(--border);
  flex-shrink: 0;
}
.book-cover-placeholder {
  width: 40px;
  height: 52px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
}

/* ===== LOADING / EMPTY ===== */
.loading, .empty-state {
  text-align: center;
  padding: 40px 20px;
  color: var(--text-muted);
  font-size: 0.875rem;
}
.loading::before { content: "⟳ "; animation: spin 1s linear infinite; display: inline-block; }
@keyframes spin { to { transform: rotate(360deg); } }

/* ===== TOAST ===== */
.toast {
  position: fixed;
  bottom: 28px;
  right: 28px;
  z-index: 9999;
  padding: 14px 22px;
  border-radius: 8px;
  font-size: 0.875rem;
  font-weight: 500;
  max-width: 340px;
  box-shadow: var(--shadow);
  animation: slideUp 0.3s ease;
  transition: opacity 0.3s;
}
.toast.hidden { display: none; }
.toast.success { background: #1a3a2a; border: 1px solid var(--success); color: var(--success); }
.toast.error   { background: #3a1a1a; border: 1px solid var(--danger);  color: var(--danger);  }
.toast.info    { background: #1a2a3a; border: 1px solid var(--primary); color: var(--primary); }

@keyframes slideUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ===== MODAL ===== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  backdrop-filter: blur(4px);
}
.modal-overlay.hidden { display: none; }
.modal {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px;
  width: 100%;
  max-width: 440px;
  box-shadow: var(--shadow);
}
.modal h2 { font-size: 1.15rem; margin-bottom: 10px; }
.modal p  { color: var(--text-muted); font-size: 0.875rem; margin-bottom: 20px; }
.modal .form-group { margin-bottom: 20px; }