* {
    margin: 0;
    padding: 0;
    font-family: 'Gill Sans', 'Gill Sans MT', Calibri, 'Trebuchet MS', sans-serif;
    box-sizing: border-box;
}

nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px;
}

.nav-links {
    display: flex;
    gap: 20px;
    list-style: none;
}

.nav-links a {
    text-decoration: none;
    color: black;
    font-weight: 500;
}

.nav-links a:hover {
    color: #1e90ff;
    font-weight: 600;
}

.logo {
    font-size: 20px;
    font-weight: bold;
}

.logo a {
    text-decoration: none;
    color: black;
}

body {
    background: rgb(51, 134, 169);
}

#lessonTitle {
    text-align: center;
    color: #fff;
    margin: 10px 0 30px;
    font-size: 2rem;
}

.learn-container {
    display: flex;
    flex-direction: row;
    align-items: flex-start;
    justify-content: center;
    gap: 40px;
    padding: 0 20px 40px;
    flex-wrap: wrap;
}

.quiz-container {
    flex: 1;
    max-width: 500px;
    background: #fff;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

.quiz-container h2 {
    font-size: 18px;
    margin-bottom: 20px;
    padding-bottom: 10px;
}

.progress {
    font-size: 14px;
    color: #777;
    margin-bottom: 8px;
}

.quiz-container button {
    padding: 20px 0;
}

.btn {
    display: block;
    width: 100%;
    padding: 10px;
    margin: 10px 0;
    font-size: 18px;
    background: #3498db;
    color: #fff;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn:hover:not([disabled]) {
    background: #2980b9;
    color: #fff;
}

.btn:disabled {
    cursor: not-allowed;
}

#next-btn {
    margin-top: 20px;
    background: grey;
    width: 150px;
    margin-left: auto;
    margin-right: auto;
    display: none;
}

.correct {
    background: green;
}

.incorrect {
    background: red;
}

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

.score-screen h2 {
    font-size: 24px;
    margin-bottom: 10px;
}

.score-screen p {
    font-size: 16px;
    margin-bottom: 20px;
    color: #555;
}

.score-screen a {
    display: inline-block;
    text-decoration: none;
}
#lessonVideo {
    width: 100%;
    max-width: 500px;
    height: auto;
    display: block;
}