/* style.css - Apple-style UI Design Tokens and Layouts */
:root {
  --bg-color: #f5f5f7;
  --card-bg: #ffffff;
  --primary-color: #0071e3;
  --primary-hover: #0077ed;
  --success-color: #34c759;
  --success-hover: #2db34f;
  --danger-color: #ff3b30;
  --text-primary: #1d1d1f;
  --text-secondary: #86868b;
  --text-light: #f5f5f7;
  --border-color: #d2d2d7;
  --border-light: #e5e5ea;
  --border-radius-sm: 8px;
  --border-radius-md: 12px;
  --border-radius-lg: 18px;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --transition-fast: 0.2s cubic-bezier(0.25, 0.1, 0.25, 1);
  --transition-normal: 0.3s cubic-bezier(0.25, 0.1, 0.25, 1);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Auth Pages (Login) */
.auth-container {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  padding: 20px;
  background-color: var(--bg-color);
}

.auth-card {
  background: var(--card-bg);
  padding: 40px 32px;
  border-radius: var(--border-radius-lg);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
  width: 100%;
  max-width: 440px;
  text-align: center;
  border: 1px solid rgba(0, 0, 0, 0.02);
}

.auth-logo {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
}

.auth-logo img {
  width: 48px;
  height: 48px;
}

.auth-logo-text {
  font-size: 1.5rem;
  font-weight: 700;
  margin-left: 12px;
  letter-spacing: -0.5px;
}

.auth-card h1 {
  font-size: 1.8rem;
  font-weight: 600;
  margin-bottom: 8px;
  letter-spacing: -0.5px;
}

.auth-subtitle {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 32px;
}

.form-group {
  margin-bottom: 20px;
  text-align: left;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--text-primary);
}

.form-input {
  width: 100%;
  padding: 12px 16px;
  font-size: 1rem;
  border-radius: var(--border-radius-md);
  border: 1px solid var(--border-color);
  background-color: #fcfcfd;
  color: var(--text-primary);
  outline: none;
  transition: var(--transition-fast);
}

.form-input:focus {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 4px rgba(0, 113, 227, 0.15);
  background-color: #ffffff;
}

.auth-error {
  background-color: rgba(255, 59, 48, 0.08);
  color: var(--danger-color);
  padding: 12px;
  border-radius: var(--border-radius-sm);
  font-size: 0.9rem;
  margin-bottom: 20px;
  display: none;
  text-align: left;
  border: 1px solid rgba(255, 59, 48, 0.15);
}

.auth-btn {
  width: 100%;
  padding: 14px;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: var(--border-radius-md);
  background-color: var(--primary-color);
  color: white;
  cursor: pointer;
  transition: var(--transition-fast);
}

.auth-btn:hover {
  background-color: var(--primary-hover);
}

.auth-btn:active {
  transform: scale(0.98);
}

/* Header UI */
.navbar {
  background-color: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-light);
  position: sticky;
  top: 0;
  z-index: 1000;
  padding: 14px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-brand {
  display: flex;
  align-items: center;
  text-decoration: none;
  color: var(--text-primary);
}

.nav-brand-title {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.nav-brand-tag {
  background-color: rgba(0, 113, 227, 0.1);
  color: var(--primary-color);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 600;
  margin-left: 8px;
  text-transform: uppercase;
}

.nav-user {
  display: flex;
  align-items: center;
  gap: 16px;
}

.user-badge {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 6px;
}

.user-badge::before {
  content: '';
  display: inline-block;
  width: 8px;
  height: 8px;
  background-color: var(--success-color);
  border-radius: 50%;
}

.logout-btn {
  background: none;
  border: 1px solid var(--border-color);
  padding: 6px 12px;
  border-radius: var(--border-radius-sm);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-primary);
  cursor: pointer;
  transition: var(--transition-fast);
}

.logout-btn:hover {
  background-color: var(--bg-color);
  border-color: var(--text-primary);
}

/* Dashboard / Library */
.dashboard-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 24px;
}

.dashboard-header {
  margin-bottom: 40px;
  text-align: left;
}

.dashboard-header h1 {
  font-size: 2.5rem;
  font-weight: 700;
  letter-spacing: -1px;
  margin-bottom: 8px;
}

.dashboard-header p {
  color: var(--text-secondary);
  font-size: 1.1rem;
}

.library-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 28px;
}

.book-card {
  background: var(--card-bg);
  border-radius: var(--border-radius-lg);
  overflow: hidden;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.03);
  border: 1px solid var(--border-light);
  display: flex;
  flex-direction: column;
  transition: var(--transition-normal);
  cursor: pointer;
  text-decoration: none;
  color: inherit;
}

.book-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.08);
  border-color: var(--border-color);
}

.book-cover-placeholder {
  height: 180px;
  background: linear-gradient(135deg, #0071e3 0%, #003b7a 100%);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  color: white;
  padding: 24px;
  text-align: center;
  position: relative;
}

.book-card:nth-child(2) .book-cover-placeholder {
  background: linear-gradient(135deg, #34c759 0%, #1c6e31 100%);
}

.book-card:nth-child(3) .book-cover-placeholder {
  background: linear-gradient(135deg, #ff9500 0%, #b36b00 100%);
}

.book-cover-title {
  font-size: 1.4rem;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.5px;
  margin-bottom: 8px;
}

.book-cover-subtitle {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  opacity: 0.8;
}

.book-details {
  padding: 24px;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.book-meta {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--primary-color);
  text-transform: uppercase;
  margin-bottom: 8px;
  letter-spacing: 0.5px;
}

.book-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 12px;
  line-height: 1.3;
}

.book-description {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 24px;
  flex-grow: 1;
}

.book-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px;
  background-color: #f5f5f7;
  color: var(--primary-color);
  font-weight: 600;
  border-radius: var(--border-radius-md);
  text-align: center;
  transition: var(--transition-fast);
}

.book-card:hover .book-action {
  background-color: var(--primary-color);
  color: white;
}

/* Responsive adjust */
@media (max-width: 600px) {
  .dashboard-header h1 {
    font-size: 2rem;
  }
  .library-grid {
    grid-template-columns: 1fr;
  }
}