:root {
    --gradient-1: linear-gradient(135deg, #4dc7d6, #34D399);
    --gradient-2: linear-gradient(135deg, #10B981, #34D399);
    --gradient-3: linear-gradient(135deg, #34D399, #4dc7d6);
    --green-soft: #10B981;
    --green-light: #34D399;
}

/* Course Layout */
.course-container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 8rem 2rem 4rem;
    position: relative;
    z-index: 1;
}

/* Course Header */
.course-header {
    text-align: center;
    margin-bottom: 4rem;
}

.course-badge {
    display: inline-flex;
    align-items: center;
    padding: 0.5rem 1.5rem;
    background: var(--gradient-1);
    color: white;
    border-radius: 50px;
    font-weight: 500;
    font-size: 0.875rem;
    margin-bottom: 1.5rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.course-title {
    font-size: 3rem;
    font-weight: 700;
    background: linear-gradient(135deg, #1e293b, #334155);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    margin-bottom: 1rem;
    line-height: 1.2;
}

/* Sections */
.section {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 2rem;
    margin-bottom: 2rem;
    border: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.05);
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.section-title {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 2rem;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.subsection-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin: 2rem 0 1rem;
    color: var(--green-soft);
}

/* Content Boxes */
.lesson-box {
    background: rgba(255, 255, 255, 0.5);
    border-radius: 15px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    border: 1px solid rgba(255, 255, 255, 0.3);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.lesson-box:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.05);
}

/* Math Content */
.math-block {
    margin: 2rem 0;
    padding: 1.5rem;
    text-align: center;
    font-size: 1.2rem;
    background: rgba(255, 255, 255, 0.7);
    border-radius: 12px;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.05);
}

/* Lists */
.examples {
    margin: 1.5rem 0;
}

.examples li {
    list-style: none;
    margin-bottom: 1rem;
    padding-left: 1.5rem;
    position: relative;
}

.examples li::before {
    content: "•";
    color: var(--green-light);
    position: absolute;
    left: 0;
    font-weight: bold;
}

.exercices {
    counter-reset: exercice;
}

.exercices li {
    list-style: none;
    margin-bottom: 1rem;
    padding-left: 2rem;
    position: relative;
}

.exercices li::before {
    counter-increment: exercice;
    content: counter(exercice);
    position: absolute;
    left: 0;
    top: 0;
    width: 24px;
    height: 24px;
    background: var(--green-soft);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.875rem;
    font-weight: 500;
}

/* Notes */
.note {
    background: linear-gradient(135deg, rgba(77, 199, 214, 0.05), rgba(52, 211, 153, 0.05));
    border-radius: 12px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    border: 1px solid rgba(77, 199, 214, 0.1);
}

/* Responsive */
@media (max-width: 768px) {
    .course-container {
        padding: 6rem 1rem 2rem;
    }

    .course-title {
        font-size: 2.5rem;
    }

    .section {
        padding: 1.5rem;
    }

    .section-title {
        font-size: 1.75rem;
    }
}