/* Reset and Base Styles */
body {
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
    background: #1e1e1e;
    color: #e0e0e0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    min-height: 100vh;
}

.header {
    background: #2a2a2a;
    padding: 1rem;
    color: #e0e0e0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.header > h2, .header > a {
    margin: 0 1rem;
    text-decoration: none;
    color: inherit;
}

.container {
    max-width: 800px;
    margin: 2rem auto;
    padding: 1rem;
    width: 90%;
    background: #2a2a2a;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    text-align: center;
}

.main-container {
    display: flex;
    width: 100%;
    max-width: 1200px;
    margin: 2rem auto;
    padding: 1rem;
    background: #2a2a2a;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.13);
}

.card {
    background: #2a2a2a;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 1px 6px rgba(0, 0, 0, 0.3);
    margin-bottom: 1.5rem;
    text-align: center;
}

a.button {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    margin-top: 1rem;
    background: #00bcd4;
    color: #fff;
    text-decoration: none;
    border-radius: 4px;
    transition: background 0.3s ease;
    border: none;
}

a.button:hover {
    background: #008ba3;
}

.logout {
    background: #dc3545;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    color: #fff;
    font-size: 0.9rem;
    text-decoration: none;
}

h1, h2, h3 {
    margin-top: 0;
    color: #e0e0e0;
}

input, select {
    width: 90%;
    display: block;
    margin: 0.5rem auto;
    padding: 0.75rem;
    border: 1px solid #555;
    border-radius: 4px;
    font-size: 1rem;
    background: #333;
    color: #e0e0e0;
}

input::placeholder {
    color: #888;
}

button {
    width: auto;
    padding: 0.75rem 2rem;
    background: #00bcd4;
    border: none;
    color: #fff;
    border-radius: 4px;
    font-size: 1rem;
    cursor: pointer;
    transition: background 0.3s ease;
}

button:hover {
    background: #008ba3;
}

.error {
    color: #e74c3c;
    margin-top: 1rem;
}

.back {
    display: inline-block;
    margin-top: 1rem;
    color: #00bcd4;
    text-decoration: none;
}

.sidebar {
    width: 200px;
    border-right: 1px solid #444;
    padding: 10px;
    background: #2a2a2a;
}

.sidebar ul {
    list-style: none;
    padding: 0;
}

.sidebar li {
    margin-bottom: 10px;
}

.sidebar a {
    text-decoration: none;
    color: #e0e0e0;
}

.sidebar a:hover {
    color: #00bcd4;
}

.content {
    flex: 1;
    padding: 10px;
    background: #2a2a2a;
}

.lesson-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px;
    border-bottom: 1px solid #444;
}

.dot-menu-container {
    position: relative;
    display: inline-block;
}

.dot-menu-button {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 18px;
    color: #e0e0e0;
}

.dropdown-menu {
    position: absolute;
    right: 0;
    background: #2a2a2a;
    border: 1px solid #555;
    box-shadow: 0 2px 5px rgba(0,0,0,0.3);
    z-index: 100;
    min-width: 100px;
}

.dropdown-item {
    padding: 8px;
    cursor: pointer;
    color: #e0e0e0;
}

.dropdown-item:hover {
    background-color: #333;
}

.filters {
    margin-bottom: 15px;
}