:root {
    --bg-color: #0f172a;
    --card-bg: rgba(30, 41, 59, 0.7);
    --text-main: #f8fafc;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
}

.glass {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 20px;
}

.hidden-view {
    display: none !important;
}

.flashcard-panel {
    cursor: pointer;
    border: 0;
    background: transparent;
    padding: 0;
}

.flashcard-scene {
    perspective: 1200px;
}

.flashcard-inner {
    position: relative;
    min-height: 320px;
    transform-style: preserve-3d;
    transition: transform 0.6s ease;
}

.flashcard-inner.is-flipped {
    transform: rotateY(180deg);
}

.flashcard-face {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    justify-content: center;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
}

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

.flashcard-panel:hover .flashcard-face {
    box-shadow: 0 16px 36px rgba(15, 23, 42, 0.28);
    border-color: rgba(45, 212, 191, 0.45);
}