:root {
    --bg-gradient: linear-gradient(135deg, #fdfbfb 0%, #ebedee 100%);
    --card-back-bg: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --card-front-bg: #ffffff;
    --text-color: #2d3748;
    --accent-color: #764ba2;
    --success-color: #48bb78;
    --font-main: 'Outfit', sans-serif;

    --shadow-sm: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 20px 25px rgba(0, 0, 0, 0.15);

    --radius-md: 12px;
    --radius-lg: 20px;
}

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

body {
    font-family: var(--font-main);
    background: var(--bg-gradient);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

#app {
    width: 100%;
    height: 100dvh;
    display: flex;
    flex-direction: column;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0.5rem;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 0.5rem;
    flex-shrink: 0;
}

h1 {
    font-weight: 700;
    font-size: 1.5rem;
    background: var(--card-back-bg);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.icon-btn {
    background: white;
    border: none;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: var(--shadow-sm);
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.icon-btn:active {
    transform: scale(0.95);
}

.score-board {
    font-size: 0.9rem;
    background: white;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    display: flex;
    gap: 1rem;
}

main {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    width: 100%;
    height: 100%;
}

.game-grid {
    display: grid;
    grid-gap: 0.5rem;
    width: 100%;
    max-width: 600px;
    margin: 0 auto;
    /* Default grid (mobile portrait) */
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(4, 1fr);
    align-content: center;
    aspect-ratio: 1 / 1;
}

/* Make grid cards square */
.card-container {
    background-color: transparent;
    perspective: 1000px;
    cursor: pointer;
    aspect-ratio: 1 / 1;
    width: 100%;
    height: 100%;
}

/* Responsive Grid Adjustments */
@media (max-width: 600px) {
    .gap-grid {
        grid-gap: 8px;
    }
}

.card {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: center;
    transition: transform 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275), box-shadow 0.3s ease;
    transform-style: preserve-3d;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

@media (hover: hover) {
    .card-container:hover .card {
        box-shadow: var(--shadow-md);
        transform: translateY(-2px);
    }

    .card-container:hover .card.flipped {
        transform: translateY(-2px) rotateY(180deg);
    }
}

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

.card.matched {
    animation: pulse-green 0.5s ease-in-out;
}

.card-face {
    position: absolute;
    width: 100%;
    height: 100%;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    border-radius: var(--radius-md);
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

.card-front {
    background: var(--card-back-bg);
    color: white;
    font-size: 2rem;
}

/* Subtle pattern for card back */
.card-front::after {
    content: '?';
    font-size: 2rem;
    opacity: 0.5;
    font-weight: bold;
}

.card-back {
    background: var(--card-front-bg);
    transform: rotateY(180deg);
    border: 2px solid transparent;
    display: flex;
    flex-direction: column;
    padding: 5px;
}

.card.matched .card-back {
    border-color: var(--success-color);
}

.card-content-img {
    width: 80%;
    height: 80%;
    object-fit: contain;
}

.card-content-text {
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--accent-color);
    word-break: break-all;
    line-height: 1.2;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 100;
    backdrop-filter: blur(4px);
    opacity: 1;
    transition: opacity 0.3s;
}

.modal.hidden {
    opacity: 0;
    pointer-events: none;
}

.modal-content {
    background: white;
    padding: 2rem;
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-lg);
    animation: slide-up 0.4s ease-out;
    max-width: 90%;
    width: 300px;
}

.primary-btn {
    margin-top: 1rem;
    background: var(--card-back-bg);
    color: white;
    border: none;
    padding: 0.8rem 1.5rem;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: opacity 0.2s;
}

.primary-btn:hover {
    opacity: 0.9;
}

/* Animations */
@keyframes slide-up {
    from {
        transform: translateY(20px);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

@keyframes pulse-green {
    0% {
        transform: scale(1) rotateY(180deg);
        box-shadow: 0 0 0 0 rgba(72, 187, 120, 0.7);
    }

    70% {
        transform: scale(1.05) rotateY(180deg);
        box-shadow: 0 0 0 10px rgba(72, 187, 120, 0);
    }

    100% {
        transform: scale(1) rotateY(180deg);
        box-shadow: 0 0 0 0 rgba(72, 187, 120, 0);
    }
}

@media (orientation: landscape) {
    #app {
        flex-direction: row;
        height: 100vh;
        padding: 0.5rem;
    }

    header {
        flex-direction: column;
        justify-content: center;
        padding-right: 1rem;
        padding-bottom: 0;
        width: 150px;
        align-items: flex-start;
        gap: 1rem;
    }

    .score-board {
        flex-direction: column;
        gap: 0.5rem;
        width: 100%;
    }

    .game-grid {
        max-width: none;
        max-height: 100%;
        width: auto;
        flex: 1;

        grid-template-columns: repeat(8, 1fr);
        grid-template-rows: repeat(2, 1fr);
        aspect-ratio: auto;
        /* Remove fixed aspect ratio in landscape */
        grid-gap: 0.5rem;
    }

    .card-container {
        aspect-ratio: auto;
    }
}

@media (max-width: 380px) {
    .card-front::after {
        font-size: 1.5rem;
    }

    .card-content-text {
        font-size: 0.7rem;
    }
}