/* Variables */
:root {
    --primary-color: #3498db;
    --secondary-color: #2ecc71;
    --hover-color: #2980b9;
    --text-color: #333;
    --bg-color: #f4f7f8;
    --box-color: #fff;
    --font-medium: 500;
    --border-radius: 10px;
    --transition-speed: 0.3s;
}

/* Reset */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
}

/* Navbar */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: var(--primary-color);
    padding: 1rem 2rem;
    color: #fff;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.navbar .logo {
    font-weight: bold;
    font-size: 1.6rem;
}

.navbar .nav-toggle {
    display: none;
    font-size: 1.8rem;
    cursor: pointer;
}

.navbar ul.sidebar {
    display: flex;
    gap: 1.5rem;
    list-style: none;
}

.navbar ul.sidebar li a {
    text-decoration: none;
    color: #fff;
    font-weight: var(--font-medium);
    padding: 0.3rem 0.5rem;
    border-radius: 5px;
    transition: background var(--transition-speed);
}

.navbar ul.sidebar li a:hover,
.navbar ul.sidebar li a.active-link {
    background-color: var(--hover-color);
}

/* Sections */
.section {
    padding: 5rem 2rem;
}

.section-title {
    font-size: 2.2rem;
    margin-bottom: 2rem;
    text-align: center;
    color: var(--primary-color);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background-color: var(--secondary-color);
    margin: 10px auto 0;
    border-radius: 2px;
}

/* Teachers */
.teachers-container {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
    justify-content: center;
}
/* Teacher images */
.teacher img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: var(--border-radius);
    margin-bottom: 1rem;
}

.teacher {
    background-color: var(--box-color);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    flex: 1 1 220px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
}

.teacher:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.15);
}

.teacher h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

/* Accordion */
.accordion-container {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    max-width: 900px;
    margin: auto;
}

.accordion-item {
    background-color: var(--box-color);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
}

.accordion-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 15px rgba(0,0,0,0.15);
}

.accordion-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.2rem 1.5rem;
    cursor: pointer;
    font-weight: var(--font-medium);
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    color: #fff;
}

.accordion-icon {
    font-size: 1.6rem;
    transition: transform var(--transition-speed);
}

.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s ease;
    padding: 0 1.5rem;
    background-color: #fefefe;
}

.accordion-item.active .accordion-content {
    padding: 1rem 1.5rem;
}

.accordion-item.active .accordion-icon {
    transform: rotate(45deg);
}

/* Group Cards */
.group-container {
    margin-bottom: 1.5rem;
}

.group-container h4 {
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.course-card {
    display: inline-block;
    margin: 0.3rem 0.5rem 0.3rem 0;
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    background-color: var(--secondary-color);
    color: #fff;
    font-weight: var(--font-medium);
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
    cursor: default;
}

.course-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}

/* Achievements */
#achievements ul {
    list-style: disc inside;
    max-width: 600px;
    margin: auto;
}

/* Responsive */
@media (max-width: 768px) {
    .navbar ul.sidebar {
        position: fixed;
        top: 0;
        right: -100%;
        width: 70%;
        height: 100%;
        background-color: var(--primary-color);
        flex-direction: column;
        padding-top: 5rem;
        gap: 2rem;
        transition: right 0.3s ease;
    }

    .navbar ul.sidebar.show-sidebar {
        right: 0;
    }

    .navbar .nav-toggle {
        display: block;
    }
}