* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;
}

body {
    background: linear-gradient(135deg, #e1dd0d 0%, #119ae3 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

.container {
    width: 100%;
    max-width: 800px;
    padding: 20px;
}

#quiz {
    background: white;
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

h1 {
    text-align: center;
    color: #333;
    margin-bottom: 30px;
    font-size: 2.5em;
    font-family: 'Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;
}

h2 {
    color: #333;
    margin-bottom: 20px;
}

.screen {
    text-align: center;
}

.hidden {
    display: none;
}

#categories-container,
#difficulty-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin: 30px 0;
}

.category-btn,
.difficulty-btn {
    background: #f8f9fa;
    color: #333;
    border: 2px solid #667eea;
    padding: 20px;
    border-radius: 10px;
    cursor: pointer;
    font-size: 16px;
    transition: all 0.3s ease;
}

.category-btn:hover,
.difficulty-btn:hover {
    background: rgb(51, 51, 204);
    color: white;
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.3);
}

.difficulty-btn {
    font-weight: bold;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.difficulty-btn[data-difficulty="easy"] {
    border-color: #4CAF50;
    color: #4CAF50;
}

.difficulty-btn[data-difficulty="easy"]:hover {
    background: #4CAF50;
    color: white;
}

.difficulty-btn[data-difficulty="medium"] {
    border-color: #FF9800;
    color: #FF9800;
}

.difficulty-btn[data-difficulty="medium"]:hover {
    background: #FF9800;
    color: white;
}

.difficulty-btn[data-difficulty="hard"] {
    border-color: #f44336;
    color: #f44336;
}

.difficulty-btn[data-difficulty="hard"]:hover {
    background: #f44336;
    color: white;
}

button {
    background: #667eea;
    color: white;
    border: none;
    padding: 12px 25px;
    border-radius: 25px;
    cursor: pointer;
    font-size: 16px;
    margin: 10px;
    transition: transform 0.2s, background 0.2s;
}

button:hover {
    background: #764ba2;
    transform: translateY(-2px);
}

.secondary-btn {
    background: transparent;
    border: 2px solid #667eea;
    color: #667eea;
}

.secondary-btn:hover {
    background: #667eea;
    color: white;
}

.quiz-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 15px;
    border-bottom: 2px solid #eee;
}

.quiz-info {
    text-align: left;
}

.quiz-info h2 {
    color: #667eea;
    font-size: 1.2em;
    margin: 0;
}

.difficulty-display {
    color: #666;
    font-size: 0.9em;
    margin-top: 5px;
}

#options-container {
    display: grid;
    gap: 10px;
    margin: 20px 0;
}

.option {
    background: #f5f5f5;
    padding: 15px;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.option:hover {
    background: #e0e0e0;
    border-color: #667eea;
}

.option.selected {
    background: #667eea;
    color: white;
}

.option.correct {
    background: #4CAF50;
    color: white;
}

.option.wrong {
    background: #f44336;
    color: white;
}

.result-info {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
    margin: 20px 0;
}

.result-info p {
    font-size: 18px;
    margin: 10px 0;
    color: #333;
}

.result-buttons {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
    margin-top: 30px;
}

#current-question-num {
    font-weight: bold;
    color: #667eea;
}

.emoji {
    text-align: center;
    font-family: Verdana, Geneva, Tahoma, sans-serif;
}

.li {
    text-decoration: none;
    color: #000;
    font-family: Verdana, Geneva, Tahoma, sans-serif;
}

/* From Uiverse.io by Emil190313 */
.toggle {
    background-color: purple;
    position: fixed;
    top: 20px;
    right: 20px;
    width: 56px;
    height: 56px;
    border-radius: 50%;
    display: grid;
    place-items: center;
    cursor: pointer;
    box-shadow: 0 0 50px 20px rgba(0, 0, 0, 0.1);
    line-height: 1;
    z-index: 1000;
}

.input {
    display: none;
}

.icon {
    grid-column: 1 / 1;
    grid-row: 1 / 1;
    transition: transform 500ms;
}

.icon--moon {
    transition-delay: 200ms;
    color: black;
}

.icon--sun {
    transform: scale(0);
    color: yellow;
}

#switch:checked+.icon--moon {
    transform: rotate(360deg) scale(0);
}

#switch:checked~.icon--sun {
    transition-delay: 200ms;
    transform: scale(1) rotate(360deg);
}