* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: #f7f8fa;
    color: #222;
}

.site-header {
    background: #ffffff;
    border-bottom: 1px solid #e5e5e5;
}

.site-logo {
    text-decoration: none;
    color: #111;
    font-weight: 700;
    font-size: 18px;
}

.main-content {
    max-width: 800px;
    margin: auto;
    padding: 20px;
}

.site-footer {
    text-align: center;
    padding: 30px 20px;
    color: #777;
    font-size: 14px;
}
.header-inner {
    max-width: 800px;
    margin: auto;
    padding: 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

@media (max-width: 600px) {
    .main-content {
        padding: 16px;
    }
}

.course-home h1 {
    font-size: 32px;
    margin-bottom: 10px;
}

.course-home > p {
    color: #666;
    margin-bottom: 30px;
}
.course-title {
    font-size: 22px;
    font-weight: 600;
    text-decoration: none;
}

.course-intro {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 30px;
    margin-bottom: 30px;
}

.course-home {
    flex: 1;
}

.samaira-image {
    width: 150px;
    height: auto;
    display: block;
}
.lesson-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.lesson-card {
    display: block;
    background: #ffffff;
    border: 1px solid #e5e5e5;
    border-radius: 12px;
    padding: 18px;
    text-decoration: none;
    color: #222;
    transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.lesson-card:hover {
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.08);
    transform: translateY(-1px);
}

.lesson-number {
    font-size: 13px;
    font-weight: 700;
    color: #666;
    margin-bottom: 6px;
}

.lesson-card h2 {
    margin: 0 0 8px;
    font-size: 19px;
    line-height: 1.35;
}

.lesson-card p {
    margin: 0;
    font-size: 14px;
    color: #777;
}

@media (max-width: 600px) {
    .course-home h1 {
        font-size: 27px;
    }

    .lesson-card {
        padding: 16px;
    }

    .lesson-card h2 {
        font-size: 18px;
    }
}

.lesson-locked {
    opacity: 0.6;
    cursor: default;
}

.lesson-locked:hover {
    transform: none;
    box-shadow: none;
}

.brand-logo img {
    height: 45px;
    width: auto;
    display: block;
}

@media (max-width: 600px) {
    .course-intro {
        gap: 15px;
    }

    .samaira-image {
        width: 100px;
    }
}