:root {
    --bg-dark: #0f172a;
    --bg-darker: #020617;
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --secondary: #ec4899;
    --secondary-hover: #db2777;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
    --danger: #ef4444;
    --success: #10b981;
}

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

body {
    font-family: 'Outfit', sans-serif;
    background: linear-gradient(135deg, var(--bg-darker) 0%, var(--bg-dark) 100%);
    color: var(--text-main);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Typography */
h1, h2, h3 {
    font-weight: 800;
    margin-bottom: 1rem;
}

.gradient-text {
    background: linear-gradient(to right, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
}

.subtitle {
    color: var(--text-muted);
    font-size: 1.1rem;
    margin-bottom: 2rem;
}

/* Glassmorphism */
.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
}

/* Buttons */
.btn {
    font-family: 'Outfit', sans-serif;
    font-weight: 600;
    font-size: 1rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

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

.btn-primary {
    background: var(--primary);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-hover);
    box-shadow: 0 0 15px rgba(59, 130, 246, 0.5);
}

.btn-secondary {
    background: var(--secondary);
    color: white;
}

.btn-secondary:hover {
    background: var(--secondary-hover);
    box-shadow: 0 0 15px rgba(236, 72, 153, 0.5);
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--glass-border);
    color: var(--text-main);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
}

.btn-sm {
    padding: 0.4rem 0.8rem;
    font-size: 0.9rem;
}

.w-100 {
    width: 100%;
}

.text-center {
    text-align: center;
}

/* Auth Page */
.auth-body {
    justify-content: center;
    align-items: center;
}

.auth-container {
    width: 90%;
    max-width: 400px;
    text-align: center;
}

.tabs {
    display: flex;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--glass-border);
}

.tab-btn {
    flex: 1;
    background: none;
    border: none;
    color: var(--text-muted);
    padding: 0.75rem;
    font-family: 'Outfit', sans-serif;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s;
}

.tab-btn.active {
    color: var(--primary);
    border-bottom: 2px solid var(--primary);
}

.auth-form {
    display: none;
    animation: fadeIn 0.4s ease;
}

.auth-form.active-form {
    display: block;
}

.input-group {
    margin-bottom: 1.25rem;
    text-align: left;
}

.input-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.input-group input {
    width: 100%;
    padding: 0.75rem;
    border-radius: 8px;
    border: 1px solid var(--glass-border);
    background: rgba(0, 0, 0, 0.2);
    color: white;
    font-family: 'Outfit', sans-serif;
    font-size: 1rem;
    outline: none;
    transition: border-color 0.3s;
}

.input-group input:focus {
    border-color: var(--primary);
}

.password-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.password-wrapper input {
    padding-right: 40px; /* Space for the icon */
}

.toggle-password {
    position: absolute;
    right: 10px;
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 5px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: color 0.2s;
}

.toggle-password:hover {
    color: var(--text-main);
}

.eye-icon {
    width: 20px;
    height: 20px;
}

.error-message {
    color: var(--danger);
    font-size: 0.85rem;
    margin-top: 0.5rem;
    min-height: 1.2rem;
}

/* Dashboard */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 5%;
    margin-bottom: 2rem;
    border-radius: 0 0 16px 16px;
    border-top: none;
    border-left: none;
    border-right: none;
}

.container {
    width: 90%;
    max-width: 800px;
    margin: 0 auto;
}

.upload-section {
    margin-bottom: 3rem;
    text-align: center;
}

.file-upload-wrapper {
    margin: 1.5rem 0;
}

.file-upload-label {
    display: inline-block;
    padding: 1rem 2rem;
    background: rgba(255,255,255,0.05);
    border: 2px dashed var(--glass-border);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
}

.file-upload-label:hover {
    background: rgba(255,255,255,0.1);
    border-color: var(--primary);
}

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.gallery-item {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    overflow: hidden;
    transition: transform 0.3s, box-shadow 0.3s;
    cursor: pointer;
}

.gallery-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.5);
    border-color: var(--primary);
}

.gallery-img-wrapper {
    width: 100%;
    padding-top: 100%; /* 1:1 Aspect Ratio */
    position: relative;
}

.gallery-img-wrapper img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.gallery-info {
    padding: 1rem;
}

.gallery-info p {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 0.2rem;
}

.gallery-info strong {
    color: var(--primary);
}

/* Game Interface */
.game-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    width: 100%;
    max-width: 600px;
    margin: 0 auto;
    padding: 1rem;
}

.level-buttons {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-top: 2rem;
}

@media (min-width: 480px) {
    .level-buttons {
        flex-direction: row;
        justify-content: center;
    }
}

.preview-container {
    margin-top: 2rem;
}

.preview-container img {
    max-width: 200px;
    max-height: 200px;
    border-radius: 8px;
    margin-top: 1rem;
    border: 2px solid var(--glass-border);
}

.puzzle-grid {
    display: grid;
    gap: 2px;
    background: var(--glass-border);
    padding: 4px;
    border-radius: 8px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.6);
    /* Width will be set via JS */
}

.puzzle-piece {
    background-size: cover;
    background-position: center;
    cursor: pointer;
    transition: transform 0.2s, filter 0.2s;
    user-select: none;
    -webkit-user-select: none;
}

.puzzle-piece.selected {
    transform: scale(0.9);
    filter: brightness(1.2);
    box-shadow: inset 0 0 0 2px var(--primary);
    z-index: 10;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.4);
    z-index: 100;
    justify-content: center;
    align-items: flex-end;
    padding-bottom: 20px;
}

.modal.active {
    display: flex;
    animation: slideUp 0.3s ease;
}

.modal-content {
    width: 90%;
    max-width: 400px;
    max-height: 50vh;
    overflow-y: auto;
}

.leaderboard-list {
    list-style: none;
    margin: 1.5rem 0;
    text-align: left;
    max-height: 200px;
    overflow-y: auto;
}

.leaderboard-list li {
    padding: 0.75rem;
    border-bottom: 1px solid var(--glass-border);
    display: flex;
    justify-content: space-between;
}

.modal-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 1.5rem;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(50px); }
    to { opacity: 1; transform: translateY(0); }
}

.loading-spinner {
    text-align: center;
    color: var(--text-muted);
    font-style: italic;
    grid-column: 1 / -1;
}