:root {
  --bg-color: #fcf9f2;
  --surface-bg: rgba(0, 0, 0, 0.05);
  --text-color: #1e293b;
  --text-muted: #64748b;
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(0, 0, 0, 0.05);
  --border-subtle: rgba(0, 0, 0, 0.05);
  --card-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.05), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
  --nav-hover: #1e293b;
  --accent-glow: rgba(79, 70, 229, 0.1);
}

[data-theme="dark"] {
  --bg-color: #0f172a;
  --surface-bg: rgba(255, 255, 255, 0.05);
  --text-color: #f1f5f9;
  --text-muted: #94a3b8;
  --glass-bg: rgba(255, 255, 255, 0.03);
  --glass-border: rgba(255, 255, 255, 0.05);
  --border-subtle: rgba(255, 255, 255, 0.05);
  --card-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
  --nav-hover: #ffffff;
  --accent-glow: rgba(79, 70, 229, 0.2);
}

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  transition:
    background-color 0.5s ease,
    color 0.5s ease;
}

body.no-scroll {
  overflow: hidden;
}

/* Button system */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-weight: 600;
  border-radius: 0.9rem;
  border-width: 1px;
  border-style: solid;
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  line-height: 1.25rem;
  transition:
    background-color 150ms ease,
    color 150ms ease,
    box-shadow 150ms ease,
    transform 150ms ease,
    border-color 150ms ease;
}

.btn-sm {
  padding: 0.35rem 0.9rem;
  font-size: 0.75rem;
  line-height: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.btn-lg {
  padding: 0.85rem 1.5rem;
  font-size: 1rem;
  line-height: 1.5rem;
}

.btn-primary {
  background-color: #4f46e5;
  color: #f9fafb;
  border-color: transparent;
  box-shadow: 0 18px 45px -20px var(--accent-glow);
}

.btn-primary:hover {
  background-color: #6366f1;
  transform: translateY(-1px);
  box-shadow: 0 22px 55px -25px var(--accent-glow);
}

.btn-primary:active {
  transform: translateY(0);
  box-shadow: 0 10px 30px -18px var(--accent-glow);
}

.btn-secondary {
  background-color: var(--surface-bg);
  color: var(--text-color);
  border-color: var(--border-subtle);
}

.btn-secondary:hover {
  background-color: rgba(148, 163, 184, 0.1);
  border-color: rgba(148, 163, 184, 0.7);
}

.btn-outline {
  background-color: transparent;
  color: var(--text-color);
  border-color: var(--border-subtle);
}

.btn-outline:hover {
  background-color: rgba(148, 163, 184, 0.08);
}

.btn-ghost {
  background-color: transparent;
  border-color: transparent;
  color: var(--text-muted);
}

.btn-ghost:hover {
  background-color: rgba(148, 163, 184, 0.08);
  color: var(--nav-hover);
}

.btn-danger {
  background-color: rgba(248, 113, 113, 0.12);
  color: #f97373;
  border-color: rgba(248, 113, 113, 0.4);
}

.btn-danger:hover {
  background-color: #f97373;
  color: #f9fafb;
}

.btn-success {
  background-color: rgba(34, 197, 94, 0.12);
  color: #22c55e;
  border-color: rgba(34, 197, 94, 0.4);
}

.btn-success:hover {
  background-color: #22c55e;
  color: #f9fafb;
}

.btn-text {
  background: transparent;
  border-color: transparent;
  padding-left: 0;
  padding-right: 0;
  border-radius: 0.75rem;
}

.btn-text:hover {
  background-color: rgba(148, 163, 184, 0.06);
}

.btn-icon {
  padding: 0.35rem;
  border-radius: 0.75rem;
  width: 2.25rem;
  height: 2.25rem;
}
.bookmark-btn,
.speak-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.25rem;
  border-radius: 0.5rem;
  min-width: 2rem;
  min-height: 2rem;
}
.bookmark-btn:hover,
.speak-btn:hover {
  background-color: var(--accent-glow);
}

.surface {
  background-color: var(--surface-bg);
}
.border-subtle {
  border-color: var(--border-subtle);
}

/* Custom Glassmorphism Utility */
.glass {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-color: var(--glass-border);
}

.text-muted {
  color: var(--text-muted);
}

/* Form elements */
input::placeholder,
textarea::placeholder {
  font-style: italic;
}

/* Card Flip Animation */
.card-container {
  perspective: 1000px;
}

.card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
  transform-style: preserve-3d;
}

.card-container.flipped .card-inner {
  transform: rotateY(180deg);
}

.card-front,
.card-back {
  position: absolute;
  width: 100%;
  height: 100%;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.card-back {
  transform: rotateY(180deg);
}

/* Gradient text animations */
.animate-gradient {
  background-size: 200% 200%;
  animation: gradient-shift 8s ease infinite;
}

@keyframes gradient-shift {
  0% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0% 50%;
  }
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--glass-border);
  border-radius: 10px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* Transitions for views */
.view {
  display: none !important;
  opacity: 0;
  transform: translateY(10px);
  transition:
    opacity 0.4s cubic-bezier(0.4, 0, 0.2, 1),
    transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.view.active {
  display: block !important;
}

.view.active.flex {
  display: flex !important;
}

.view.visible {
  opacity: 1;
  transform: translateY(0);
}

.card-container,
.card-inner {
  background: transparent !important;
}