:root {
    --bg-color: #1e1e1e;
    --panel-bg: #2d2d2d;
    --accent-color: #4a90e2;
    --text-color: #ffffff;
    --text-muted: #aaaaaa;
    --tile-bg: #3a3a3a;
    --empty-bg: #252525;
    --border-color: #444444;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.game-container {
    display: flex;
    flex-direction: row;
    gap: 30px;
    background-color: var(--panel-bg);
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 8px 24px rgba(0,0,0,0.5);
    max-width: 950px;
    width: 100%;
}

/* Header & Help-knop styling */
.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 10px;
}

h1 {
    font-size: 1.8rem;
    color: var(--accent-color);
}

#help-btn {
    background-color: var(--tile-bg);
    color: var(--accent-color);
    border: 2px solid var(--accent-color);
    font-size: 1rem;
    font-weight: bold;
    font-family: 'Courier New', Courier, monospace; /* Maakt de 'i' mooi strak */
    width: 28px;
    height: 28px;
    border-radius: 50%; /* Maakt de knop perfect rond */
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: all 0.2s ease;
    padding: 0;
}

#help-btn:hover {
    background-color: var(--accent-color);
    color: #ffffff;
    transform: scale(1.1);
}

/* Zijbalk styling */
.control-panel {
    flex: 1;
    min-width: 250px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

label {
    font-weight: bold;
    font-size: 0.9rem;
    color: var(--text-muted);
}

select, .control-panel > button {
    padding: 10px;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    background-color: var(--tile-bg);
    color: var(--text-color);
    font-size: 1rem;
    outline: none;
    cursor: pointer;
}

select:focus {
    border-color: var(--accent-color);
}

.mode-options {
    display: flex;
    gap: 15px;
}

.mode-options label {
    color: var(--text-color);
    cursor: pointer;
    font-weight: normal;
}

/* Standaard afbeeldingen grid */
.theme-images {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 8px;
    margin-bottom: 8px;
}

.theme-img {
    width: 100%;
    aspect-ratio: 1;
    object-fit: cover;
    border-radius: 4px;
    cursor: pointer;
    border: 2px solid transparent;
    transition: transform 0.2s;
}

.theme-img:hover {
    transform: scale(1.05);
}

.theme-img.active {
    border-color: var(--accent-color);
}

input[type="file"] {
    display: none;
}

.custom-file-upload {
    display: block;
    text-align: center;
    padding: 8px;
    background-color: #333;
    border: 1px dashed var(--accent-color);
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.85rem;
    color: var(--text-color);
}

/* Statistieken */
.stats {
    display: flex;
    justify-content: space-between;
    background-color: var(--bg-color);
    padding: 12px;
    border-radius: 6px;
    font-size: 1.1rem;
    font-weight: bold;
}

#restart-btn {
    background-color: var(--accent-color);
    border: none;
    font-weight: bold;
    transition: background 0.2s;
}

#restart-btn:hover {
    background-color: #357abd;
}

/* Puzzelbord */
.board-wrapper {
    position: relative;
    flex: 1.3;
    display: flex;
    justify-content: center;
    align-items: center;
}

#puzzle-board {
    display: grid;
    gap: 2px;
    background-color: var(--border-color);
    border: 4px solid var(--border-color);
    border-radius: 8px;
    width: 450px;
    height: 450px;
    max-width: 100%;
    aspect-ratio: 1;
}

.tile {
    background-color: var(--tile-bg);
    color: var(--text-color);
    font-size: 1.8rem;
    font-weight: bold;
    display: flex;
    justify-content: center;
    align-items: center;
    user-select: none;
    cursor: pointer;
    position: relative;
    border-radius: 4px;
    background-size: 450px 450px;
}

.tile .tile-number {
    position: absolute;
    top: 5px;
    left: 5px;
    font-size: 0.8rem;
    background-color: rgba(0, 0, 0, 0.6);
    color: #fff;
    padding: 2px 5px;
    border-radius: 3px;
    pointer-events: none;
}

.tile.empty {
    background: var(--empty-bg) !important;
    cursor: default;
    box-shadow: inset 0 0 10px rgba(0,0,0,0.5);
}

/* Win melding overlay */
#win-message {
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background-color: rgba(45, 45, 45, 0.9);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.8rem;
    font-weight: bold;
    color: #2ecc71;
    border-radius: 8px;
    z-index: 10;
    text-align: center;
    padding: 20px;
}

/* HANDLEIDING POP-UP (MODAL) STYLING */
.modal {
    position: fixed;
    z-index: 100;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.modal-content {
    background-color: var(--panel-bg);
    padding: 25px;
    border-radius: 10px;
    max-width: 500px;
    width: 100%;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 20px rgba(0,0,0,0.6);
    position: relative;
    animation: fadeIn 0.3s ease-out;
}

.modal-content h2 {
    color: var(--accent-color);
    margin-bottom: 10px;
}

.modal-content hr {
    border: 0;
    height: 1px;
    background: var(--border-color);
    margin-bottom: 15px;
}

.modal-content h3 {
    margin: 10px 0 5px 0;
    font-size: 1.1rem;
}

.modal-content p, .modal-content ul {
    color: #dddddd;
    font-size: 0.95rem;
    line-height: 1.5;
    margin-bottom: 12px;
}

.modal-content ul {
    padding-left: 20px;
}

.modal-content li {
    margin-bottom: 6px;
}

.close-modal {
    position: absolute;
    top: 15px;
    right: 20px;
    color: var(--text-muted);
    font-size: 2rem;
    font-weight: bold;
    cursor: pointer;
}

.close-modal:hover {
    color: var(--text-color);
}

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

.hidden {
    display: none !important;
}

/* Mobiele responsive layout */
@media (max-width: 768px) {
    body {
        padding: 10px;
    }
    .game-container {
        flex-direction: column;
        padding: 15px;
        gap: 20px;
    }
    #puzzle-board {
        width: 100%;
        height: auto;
    }
    .tile {
        font-size: 1.4rem;
        background-size: 100vw 100vw;
    }
}