/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  border-radius: 12px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: all var(--transition-fast);
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background-color: var(--midnight);
  color: #fff;
  border: 1px solid var(--midnight);
}

.btn-primary:hover {
  background-color: var(--midnight-2);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(15, 27, 45, 0.2);
}

/* Gold glow effect on hover */
.btn-primary::after {
  content: '';
  position: absolute;
  top: 0; left: -100%;
  width: 100%; height: 100%;
  background: linear-gradient(90deg, transparent, rgba(212, 175, 55, 0.2), transparent);
  transition: 0.5s;
}

.btn-primary:hover::after {
  left: 100%;
}

.btn-secondary {
  background-color: transparent;
  color: var(--midnight);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background-color: rgba(15, 27, 45, 0.04);
  border-color: var(--midnight);
}

.btn-outline {
  border: 1px solid var(--gold);
  color: var(--gold);
}

.btn-outline:hover {
  background-color: var(--gold);
  color: #fff;
}

.btn-google {
  background-color: #fff;
  color: var(--text);
  border: 1px solid var(--border);
  display: flex;
  gap: 10px;
  width: 100%;
}

.btn-google:hover {
  background-color: #f8f9fa;
  box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

/* --- Cards --- */
.card {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 24px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  transition: var(--transition-normal);
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 40px rgba(15, 27, 45, 0.12);
}

/* --- Inputs --- */
.input-group {
  margin-bottom: 20px;
}

.input-label {
  display: block;
  font-weight: 500;
  margin-bottom: 8px;
  color: var(--midnight);
  font-size: 0.9rem;
}

.input-field {
  width: 100%;
  padding: 12px 16px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: #fdfdfd;
  font-size: 1rem;
  transition: var(--transition-fast);
  font-family: var(--font-sans);
}

.input-field:focus {
  outline: none;
  border-color: var(--midnight);
  box-shadow: 0 0 0 4px rgba(15, 27, 45, 0.1);
}

/* --- Navbar --- */
.navbar {
  position: fixed;
  top: 0; left: 0; width: 100%;
  padding: 16px 0;
  background: rgba(247, 244, 238, 0.9);
  backdrop-filter: blur(10px);
  z-index: 100;
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s;
}

.navbar.scrolled {
  border-color: var(--border);
  background: rgba(255, 255, 255, 0.95);
}

.nav-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--midnight);
}

.nav-links {
  display: flex;
  gap: 24px;
}

/* --- Toast --- */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.toast {
  padding: 16px 20px;
  border-radius: 12px;
  background: #fff;
  box-shadow: 0 8px 24px rgba(0,0,0,0.12);
  display: flex;
  align-items: center;
  gap: 12px;
  animation: slideIn 0.3s ease forwards;
  min-width: 300px;
  border-left: 4px solid var(--midnight);
}

.toast.success { border-color: #32D583; }
.toast.error { border-color: #F04438; }

@keyframes slideIn {
  from { transform: translateX(100%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

/* --- Modal --- */
.modal-overlay {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: rgba(15, 27, 45, 0.6);
  z-index: 1000;
  display: flex;
  justify-content: center;
  align-items: center;
  opacity: 0;
  visibility: hidden;
  transition: 0.3s;
  backdrop-filter: blur(4px);
}

.modal-overlay.open {
  opacity: 1;
  visibility: visible;
}

.modal-content {
  background: #fff;
  padding: 32px;
  border-radius: 20px;
  width: 90%;
  max-width: 500px;
  transform: scale(0.9);
  transition: 0.3s;
  box-shadow: 0 20px 50px rgba(0,0,0,0.2);
}

.modal-overlay.open .modal-content {
  transform: scale(1);
}

/* Book details modal styles */
.book-details-content {
  max-width: 600px;
  display: flex;
  gap: 24px;
  align-items: flex-start;
}

.book-details-cover {
  flex-shrink: 0;
  width: 180px;
}

.book-details-info {
  flex: 1;
}

/* Mobile responsive modal styles */
@media (max-width: 600px) {
  .modal-content {
    padding: 20px !important;
    width: 95% !important;
  }
  
  .book-details-content {
    flex-direction: column !important;
    align-items: center !important;
    gap: 16px !important;
    max-height: 90vh;
    overflow-y: auto;
  }
  
  .book-details-cover {
    width: 140px !important;
  }
  
  #book-details-modal h2 {
    font-size: 1.4rem !important;
    text-align: center;
  }
  
  #book-details-modal .close-modal {
    position: absolute !important;
    top: 10px !important;
    right: 15px !important;
  }
  
  #book-details-modal #detail-author,
  #book-details-modal #detail-genre {
    text-align: center;
  }
  
  #book-details-modal #detail-desc {
    max-height: 150px !important;
  }
}

/* --- Skeleton Loading --- */
.skeleton {
  background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: 8px;
}

@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* --- Cover Upload Widget --- */
.cover-upload-area {
    border: 2px dashed var(--border);
    border-radius: 12px;
    padding: 24px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition-fast);
    background: #fafafa;
    position: relative;
    overflow: hidden;
    height: 100%;
    min-height: 200px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: var(--muted);
}

.cover-upload-area:hover {
    border-color: var(--midnight);
    background: #f0f0f0;
}

.cover-upload-icon {
    font-size: 2rem;
    margin-bottom: 8px;
    opacity: 0.5;
}

.cover-preview {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    object-fit: cover;
    z-index: 2;
    background: #fff;
    display: none;
}

.cover-preview.active {
    display: block;
}

.remove-cover-btn {
    position: absolute;
    top: 8px; right: 8px;
    background: rgba(0,0,0,0.6);
    color: #fff;
    border: none;
    border-radius: 50%;
    width: 24px; height: 24px;
    cursor: pointer;
    z-index: 3;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    line-height: 1;
}

.cover-preview.active + .remove-cover-btn {
    display: flex;
}

/* --- Custom Range Slider --- */
input[type=range] {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    margin: 10px 0;
    background: transparent;
}

input[type=range]:focus {
    outline: none;
}

/* Webkit (Chrome/Safari) */
input[type=range]::-webkit-slider-runnable-track {
    width: 100%;
    height: 6px;
    cursor: pointer;
    background: rgba(15, 27, 45, 0.1);
    border-radius: 3px;
    transition: 0.2s;
}

input[type=range]::-webkit-slider-thumb {
    height: 20px;
    width: 20px;
    border-radius: 50%;
    background: var(--gold);
    cursor: pointer;
    -webkit-appearance: none;
    margin-top: -7px; /* (trackHeight/2) - (thumbHeight/2) */
    box-shadow: 0 2px 6px rgba(0,0,0,0.2);
    border: 2px solid #fff;
    transition: 0.2s;
}

input[type=range]:hover::-webkit-slider-thumb {
    transform: scale(1.1);
    background: var(--midnight);
}

/* Firefox */
input[type=range]::-moz-range-track {
    width: 100%;
    height: 6px;
    cursor: pointer;
    background: rgba(15, 27, 45, 0.1);
    border-radius: 3px;
}

input[type=range]::-moz-range-thumb {
    height: 20px;
    width: 20px;
    border: 2px solid #fff;
    border-radius: 50%;
    background: var(--gold);
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(0,0,0,0.2);
}

/* Modal Typography */
.modal-title {
    font-family: var(--font-serif);
    color: var(--midnight);
    font-size: 1.8rem;
    margin-bottom: 8px;
}

.modal-book-title {
    font-family: var(--font-serif);
    color: var(--muted);
    font-size: 1.1rem;
    margin-bottom: 32px;
    font-style: italic;
    border-bottom: 1px solid var(--border);
    padding-bottom: 16px;
}