:root {
    --primary-color: #3498db;
    --secondary-color: #2c3e50;
    --accent-color: #e74c3c;
    --bg-color: #f7f9fc;
    --card-bg: #ffffff;
    --text-color: #333;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    color: var(--text-color);
}

.container {
    width: 100%;
    max-width: 600px;
    padding: 20px;
    background-color: var(--card-bg);
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    text-align: center;
    overflow: hidden;
    position: relative;
}

.screen {
    display: none;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.screen.active {
    display: flex;
}

h1 {
    font-size: 2.5rem;
    color: var(--secondary-color);
    margin-bottom: 10px;
}

.description {
    font-size: 1.1rem;
    color: #666;
    margin-bottom: 20px;
}

.settings {
    margin-bottom: 20px;
}

.settings input {
    padding: 8px;
    border: 1px solid #ccc;
    border-radius: 4px;
    width: 60px;
    text-align: center;
    font-size: 1rem;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 1.2rem;
    cursor: pointer;
    transition: transform 0.1s, opacity 0.2s;
}

.btn:active {
    transform: scale(0.98);
}

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

.btn.secondary {
    background-color: transparent;
    border: 2px solid var(--secondary-color);
    color: var(--secondary-color);
    text-decoration: none;
    display: inline-block;
}

/* Game Screen */
.header {
    width: 100%;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.score-board {
    font-size: 1.5rem;
    font-weight: bold;
    align-self: flex-start;
}

.timer-bar-container {
    width: 100%;
    height: 10px;
    background-color: #eee;
    border-radius: 5px;
    overflow: hidden;
}

#timer-bar {
    height: 100%;
    background-color: var(--accent-color);
    width: 100%;
    transition: width 0.1s linear;
}

.progress {
    align-self: flex-end;
    font-size: 0.9rem;
    color: #888;
}

.game-area {
    width: 100%;
    margin-top: 20px;
}

#stem-container {
    margin-bottom: 40px;
}

#stem-word {
    font-size: 8rem;
    margin: 0;
    line-height: 1;
    font-weight: bold; /* Bold Font */
}

#options-container {
    display: grid;
    grid-template-columns: repeat(3, 1fr); /* 3 Columns */
    gap: 15px;
    width: 100%;
}

.option-btn {
    padding: 20px;
    font-size: 2rem;
    font-weight: bold; /* Bold Font */
    border: 2px solid #ddd;
    border-radius: 8px;
    background-color: white;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
}

.option-btn:hover {
    background-color: #f0f0f0;
}

/* Feedback */
.feedback {
    height: 20px;
    font-weight: bold;
}

.feedback.correct {
    color: #27ae60;
}

.feedback.wrong {
    color: #c0392b;
}

/* End Screen */
.result-card {
    background-color: #f8f9fa;
    padding: 20px;
    border-radius: 8px;
    width: 100%;
    margin-bottom: 20px;
}

.result-card p {
    font-size: 1.5rem;
    margin: 10px 0;
}