:root {
    --bg-slate-900: #0F172A;
    --bg-slate-800: #1E293B;
    --text-cyan-400: #22D3EE;
    --bg-cyan-500: #06B6D4;
    --border-slate-700: #334155;
    --text-slate-200: #E2E8F0;
    --text-slate-400: #94A3B8;
}

body {
    background-color: var(--bg-slate-900);
    color: var(--text-slate-200);
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

.navbar {
    background-color: rgba(30, 41, 59, 0.8); /* bg-slate-800 with opacity */
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-slate-700);
}

.puzzle-board {
    background-color: var(--bg-slate-900);
    border: 2px dashed var(--border-slate-700);
    aspect-ratio: 4 / 3;
    transition: background-color 0.3s;
}

.pieces-tray {
    background-color: var(--bg-slate-800);
    border-radius: 0.75rem;
    max-height: 80vh;
    overflow-y: auto;
    border: 1px solid var(--border-slate-700);
}

.btn-cyan {
    background-color: var(--bg-cyan-500);
    color: var(--bg-slate-900);
    font-weight: bold;
    border: none;
    transition: background-color 0.2s;
}

.btn-cyan:hover {
    background-color: var(--text-cyan-400);
    color: var(--bg-slate-900);
}

.form-select {
    background-color: var(--bg-slate-800);
    color: var(--text-slate-200);
    border-color: var(--border-slate-700);
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3e%3cpath fill='none' stroke='%2394a3b8' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='m2 5 6 6 6-6'/%3e%3c/svg%3e");
}
.form-select:focus {
    background-color: var(--bg-slate-800);
    color: var(--text-slate-200);
    border-color: var(--text-cyan-400);
    box-shadow: 0 0 0 0.25rem rgba(34, 211, 238, 0.25);
}

.text-cyan {
    color: var(--text-cyan-400);
}

.text-slate-400 {
    color: var(--text-slate-400);
}

.rounded-xl {
    border-radius: 0.75rem;
}

/* --- Gallery --- */
.gallery-scroll-container {
    overflow-x: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--border-slate-700) var(--bg-slate-900);
}

.gallery-scroll-container::-webkit-scrollbar {
    height: 8px;
}

.gallery-scroll-container::-webkit-scrollbar-track {
    background: var(--bg-slate-900);
}

.gallery-scroll-container::-webkit-scrollbar-thumb {
    background-color: var(--border-slate-700);
    border-radius: 10px;
    border: 2px solid var(--bg-slate-900);
}

.gallery-item {
    display: block;
    flex: 0 0 auto; /* Prevent shrinking */
    width: 150px; /* Fixed width for items */
    height: 112px; /* Fixed height for items (4:3 ratio) */
    transition: transform 0.2s ease-in-out;
}

.gallery-item:hover {
    transform: scale(1.05);
}

.gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover; /* Ensure images fill the container */
}