/* ==========================================================================
   Base Styles
   ========================================================================== */
body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: #f3f4f6;
    color: #1f2937;
    /* Prevent pull-to-refresh on mobile if using custom scrolling areas */
    overscroll-behavior-y: none;
}

/* ==========================================================================
   Rest of the SPA styles goes here. 
   ========================================================================== */

/* --- 3D Flashcard Flip Utilities --- */
.perspective-1000 {
    perspective: 1000px;
}

.preserve-3d {
    transform-style: preserve-3d;
}

.backface-hidden {
    backface-visibility: hidden;
}

.rotate-y-180 {
    transform: rotateY(180deg);
}

/* --- Loader Spinner --- */
.loader {
    border: 3px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    border-top: 3px solid var(--primary-500, #f97316);
    width: 24px;
    height: 24px;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* --- Onboarding Slider --- */
.step-container {
    display: flex;
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    width: 100%;
}

.step-pane {
    min-width: 100%;
    flex-shrink: 0;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.step-pane.active {
    opacity: 1;
    pointer-events: auto;
}

/* Sleek dark scrollbar */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: #374151; /* gray-700 */
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: #4b5563; /* gray-600 */
}