:root {
    --bg-color: #f5f7fa;
    --card-bg: #ffffff;
    --card-border: #e1e5eb;
    --primary-text: #333333;
    --secondary-text: #666666;
    --accent-color: #4a7bff;
    --success-color: #28a745;
    --warning-color: #ffc107;
    --error-color: #dc3545;
    --water-color: #4a7bff;
    --fire-color: #ff6b6b;
    --earth-color: #4cd964;
    --wind-color: #d8d8d8;
    --cloud-color: #f1f1f1;
    --steam-color: #b3b3b3;
    --font-family: 'Poppins', sans-serif;
    --shadow-light: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-medium: 0 4px 8px rgba(0, 0, 0, 0.1);
    --shadow-heavy: 0 8px 16px rgba(0, 0, 0, 0.15);
    --transition-fast: 0.15s ease;
    --transition-medium: 0.25s ease;
    --transition-slow: 0.4s ease;
    --border-radius: 12px;
    --card-radius: 8px;
}

[data-theme="dark"] {
    --bg-color: #1a1a1a;
    --card-bg: #2c2c2c;
    --card-border: #444444;
    --primary-text: #ffffff;
    --secondary-text: #b3b3b3;
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--primary-text);
    margin: 0;
    padding: 0;
    min-height: 100vh;
    overflow-x: hidden;
    transition: background-color var(--transition-medium);
}

/* Game Container */
#game-wrapper {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    height: 100vh;
    background-color: transparent;
}

/* Header */
header {
    display: flex;
    align-items: center;
    padding: 0.75rem 0;
}

.back-button {
    font-weight: 600;
    cursor: pointer;
    transition: color var(--transition-fast);
    position: fixed; /* Changed to fixed for viewport positioning */
    top: 1rem;
    left: 1rem;
    text-decoration: none; /* Remove underline from anchor tag */
    color: var(--primary-text); /* Ensure text color matches */
    z-index: 1001; /* Ensure it's above other content */
}

.back-button:hover {
    color: var(--accent-color);
}


/* Game Title */
.game-title-container {
    text-align: center;
    margin-bottom: 1.5rem;
}

.game-title {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.game-subtitle {
    font-size: 1rem;
    color: var(--secondary-text);
}

/* Main Game Area */
#game-main {
    display: flex;
    flex: 1;
    gap: 1.5rem;
    height: calc(100vh - 200px);
}

/* Element Board */
#element-board {
    flex: 1;
    background-color: var(--bg-color);
    border-radius: var(--border-radius);
    position: relative;
    overflow: hidden;
    min-height: 400px;
    box-shadow: var(--shadow-light);
    border: 1px solid var(--card-border);
}

/* Element Cards */
.element-card {
    position: absolute;
    width: 120px;
    height: 60px;
    background-color: var(--card-bg);
    border-radius: var(--card-radius);
    box-shadow: var(--shadow-medium);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    cursor: grab;
    user-select: none;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
    border: 1px solid var(--card-border);
    will-change: transform;
    touch-action: none;
    padding: 0.5rem;
}

.element-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-heavy);
}

.element-card.dragging {
    cursor: grabbing;
    z-index: 1000;
    opacity: 0.9;
    transform: scale(1.05);
    box-shadow: var(--shadow-heavy);
}

.element-symbol {
    font-size: 1.5rem;
    margin-bottom: 0.25rem;
}

.element-name {
    font-size: 0.9rem;
    font-weight: 600;
    text-align: center;
}

/* Water Element */
.element-card[data-element="Water"] {
    background-color: rgba(74, 123, 255, 0.1);
    border-color: var(--water-color);
}

/* Fire Element */
.element-card[data-element="Fire"] {
    background-color: rgba(255, 107, 107, 0.1);
    border-color: var(--fire-color);
}

/* Earth Element */
.element-card[data-element="Earth"] {
    background-color: rgba(76, 217, 100, 0.1);
    border-color: var(--earth-color);
}

/* Wind Element */
.element-card[data-element="Wind"] {
    background-color: rgba(216, 216, 216, 0.1);
    border-color: var(--wind-color);
}

/* Cloud Element */
.element-card[data-element="Cloud"] {
    background-color: rgba(241, 241, 241, 0.1);
    border-color: var(--cloud-color);
}

/* Steam Element */
.element-card[data-element="Steam"] {
    background-color: rgba(179, 179, 179, 0.1);
    border-color: var(--steam-color);
}

/* Universe Journal */
#universe-journal {
    width: 300px;
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
    display: flex;
    flex-direction: column;
    border: 1px solid var(--card-border);
    overflow: hidden;
}

.journal-header {
    padding: 1rem;
    border-bottom: 1px solid var(--card-border);
}

.journal-controls {
    display: flex;
    gap: 0.5rem;
    margin-top: 1rem;
}

.journal-controls button {
    background-color: var(--bg-color);
    border: 1px solid var(--card-border);
    border-radius: var(--card-radius);
    padding: 0.5rem 0.75rem;
    font-size: 0.85rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    transition: background-color var(--transition-fast);
}

.journal-controls button:hover {
    background-color: var(--card-border);
}

.journal-controls button.active {
    background-color: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
}

.search-container {
    position: relative;
    margin-bottom: 0.5rem;
}

#search-elements {
    width: 100%;
    padding: 0.75rem 1rem 0.75rem 2.5rem;
    border-radius: var(--card-radius);
    border: 1px solid var(--card-border);
    background-color: var(--bg-color);
    color: var(--primary-text);
    font-family: var(--font-family);
    font-size: 0.9rem;
    transition: border-color var(--transition-fast);
}

#search-elements:focus {
    outline: none;
    border-color: var(--accent-color);
}

.search-icon {
    position: absolute;
    left: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--secondary-text);
}

#journal-content-wrapper {
    flex: 1;
    overflow-y: auto;
    padding: 0.5rem;
}

#journal-content {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.journal-element {
    padding: 0.75rem;
    border-radius: var(--card-radius);
    background-color: var(--bg-color);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    cursor: pointer;
    transition: background-color var(--transition-fast);
}

.journal-element:hover {
    background-color: var(--card-border);
}

.journal-element-symbol {
    font-size: 1.25rem;
    width: 30px;
    text-align: center;
}

.journal-element-name {
    font-weight: 600;
    font-size: 0.9rem;
}

/* Game Controls */
.game-controls {
    display: flex;
    justify-content: center;
    margin-top: 1rem;
    padding: 0.5rem;
}

#reset-button {
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    color: var(--primary-text);
    padding: 0.5rem 1.5rem;
    border-radius: var(--card-radius);
    font-family: var(--font-family);
    font-weight: 600;
    cursor: pointer;
    transition: background-color var(--transition-fast);
}

#reset-button:hover {
    background-color: var(--card-border);
}

/* Toast Notifications */
#toast-container {
    position: fixed;
    bottom: 1rem;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    width: 300px;
}

.toast {
    background-color: var(--card-bg);
    border-radius: var(--card-radius);
    padding: 1rem;
    box-shadow: var(--shadow-heavy);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    animation: slideUp 0.3s ease forwards;
    border: 1px solid var(--card-border);
}

.toast-success {
    border-left: 4px solid var(--success-color);
}

.toast-icon {
    font-size: 1.25rem;
}

.toast-message {
    font-size: 0.9rem;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Merge Animation */
.merge-animation {
    position: absolute;
    z-index: 999;
    pointer-events: none;
    animation: mergeAndFade 0.6s ease forwards;
}

@keyframes mergeAndFade {
    0% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.8;
        transform: scale(0.9);
    }
    100% {
        opacity: 0;
        transform: scale(0.5);
    }
}

/* Game Footer */
.game-footer {
    text-align: center;
    margin-top: 1rem;
    font-size: 0.8rem;
    color: var(--secondary-text);
}

/* Responsive Design */
@media (max-width: 768px) {
    #game-main {
        flex-direction: column;
        height: auto;
    }

    #universe-journal {
        width: 100%;
        height: 300px;
    }

    .element-card {
        width: 100px;
        height: 50px;
    }

    .element-symbol {
        font-size: 1.25rem;
    }

    .element-name {
        font-size: 0.8rem;
    }
}