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

html, body {
    margin: 0;
    padding: 0;
    width: 100%;
    overflow-x: hidden;
    font-family: Arial, sans-serif;
    background-color: #f0f0f0;
}

.header {
    background: linear-gradient(135deg, #7fb3d3, #4a90e2);
    color: white;
    text-align: center;
    padding: 20px 0;
}

.header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
}

.header p {
    font-size: 1.2em;
}

.navigation {
    background-color: #e8e8e8;
    padding: 10px 0;
    text-align: center;
    border-bottom: 1px solid #ddd;
}

.navigation a {
    color: #4a90e2;
    text-decoration: none;
    margin: 0 5px;
}

.navigation a:hover {
    text-decoration: underline;
}

.container {
    display: flex;
    width: 100vw;
    margin: 0;
    gap: 0;
    padding: 20px 0;
    box-sizing: border-box;
    position: relative;
    min-height: calc(100vh - 200px);
}

.sidebar {
    width: 250px;
    background-color: #f8f9fa;
    padding: 15px;
    border-radius: 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    min-height: calc(100vh - 200px);
    box-sizing: border-box;
}

.sidebar:first-of-type {
    position: absolute;
    left: 0;
    top: 20px;
    padding-left: 20px;
    padding-right: 15px;
    border-right: 1px solid #e0e0e0;
}

.sidebar:last-of-type {
    position: absolute;
    right: 0;
    top: 20px;
    padding-left: 15px;
    padding-right: 20px;
    border-left: 1px solid #e0e0e0;
}

.main-content {
    flex: 1;
    background-color: white;
    padding: 30px;
    border-radius: 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    min-height: calc(100vh - 200px);
    margin-left: 250px;
    margin-right: 250px;
    width: calc(100vw - 500px);
}

.sidebar h3 {
    color: #4a90e2;
    margin-bottom: 15px;
    font-size: 1.2em;
}

.sidebar p {
    color: #666;
    line-height: 1.6;
    font-size: 0.9em;
}

.main-content {
    flex: 1;
    background-color: white;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    text-align: center;
}

.login-form {
    max-width: 400px;
    margin: 0 auto;
}

.login-form h2 {
    color: #333;
    margin-bottom: 20px;
}

.form-group {
    margin-bottom: 15px;
    text-align: left;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    color: #333;
}

.form-group input {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 1em;
}

.submit-btn {
    background-color: #4a90e2;
    color: white;
    padding: 12px 30px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1em;
    margin-top: 15px;
}

.submit-btn:hover {
    background-color: #357abd;
}

.forgot-password {
    margin-top: 15px;
}

.forgot-password a {
    color: #4a90e2;
    text-decoration: none;
    font-size: 0.9em;
}

.forgot-password a:hover {
    text-decoration: underline;
}

.aufgaben-bereich {
    margin-top: 20px;
}

.aufgaben-liste {
    display: grid;
    gap: 20px;
    margin-top: 20px;
}

.aufgabe-item {
    background-color: #f8f9fa;
    padding: 20px;
    border-radius: 8px;
    border-left: 4px solid #4a90e2;
}

.aufgabe-item h4 {
    color: #333;
    margin-bottom: 10px;
}

.aufgabe-item p {
    color: #666;
    margin-bottom: 15px;
}

.aufgabe-link {
    background-color: #4a90e2;
    color: white;
    padding: 8px 16px;
    text-decoration: none;
    border-radius: 4px;
    font-size: 0.9em;
}

.aufgabe-link:hover {
    background-color: #357abd;
}

.no-aufgaben {
    text-align: center;
    color: #666;
    font-style: italic;
    margin-top: 40px;
}

.nav-links {
    list-style: none;
}

.nav-links li {
    margin-bottom: 10px;
}

.nav-links a {
    color: #4a90e2;
    text-decoration: none;
    display: block;
    padding: 8px 0;
    border-bottom: 1px solid #e0e0e0;
}

.nav-links a:hover {
    background-color: #e8f4f8;
    padding-left: 10px;
    transition: all 0.3s ease;
}

.nav-links a.active {
    font-weight: bold;
    background-color: #e8f4f8;
    padding-left: 10px;
}

.themen-liste {
    max-height: 500px;
    overflow-y: auto;
}

.thema-container {
    margin: 8px 0;
    border-radius: 4px;
    border: 1px solid #e0e0e0;
    overflow: hidden;
}

.thema-header {
    background: #f8f9fa;
    padding: 12px;
    border-left: 3px solid #4a90e2;
    color: #333;
    font-size: 0.9em;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background-color 0.3s ease;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

.thema-header:hover {
    background: #e8f4f8;
}

.thema-header:active {
    background: #d0e8f0;
}

.thema-arrow {
    font-size: 0.8em;
    color: #4a90e2;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: inline-block;
}

.thema-arrow.rotated {
    transform: rotate(180deg);
}

.unterthemen-container {
    max-height: 0;
    overflow: hidden;
    background: #ffffff;
    opacity: 0;
    transition: max-height 0.3s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.2s ease;
}

.unterthemen-container.expanded {
    max-height: 500px;
    opacity: 1;
    transition: max-height 0.3s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.3s ease;
}

.unterthemen-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.unterthemen-list li {
    padding: 8px 12px 8px 30px;
    border-bottom: 1px solid #f0f0f0;
    color: #666;
    font-size: 0.85em;
    position: relative;
}

.unterthemen-list li:last-child {
    border-bottom: none;
}

.unterthemen-list li::before {
    content: "•";
    color: #4a90e2;
    position: absolute;
    left: 18px;
}

.unterthemen-list li:hover {
    background: #f8f9fa;
    color: #333;
    cursor: pointer;
}

.thema-header.no-arrow {
    cursor: default;
}

.thema-header.no-arrow:hover {
    background: #f8f9fa;
}

.qr-section {
    margin-bottom: 20px;
    text-align: center;
}

.qr-placeholder {
    width: 100px;
    height: 100px;
    background-color: #e9ecef;
    border: 2px dashed #adb5bd;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto;
    border-radius: 8px;
}

.qr-placeholder p {
    color: #6c757d;
    font-size: 0.8em;
    margin: 0;
}

.array-structure {
    margin-top: 30px;
    background: #f8f9fa;
    padding: 20px;
    border-radius: 8px;
    border: 1px solid #e9ecef;
}

.array-structure h3 {
    color: #333;
    margin-bottom: 15px;
}

.array-structure pre {
    background: #fff;
    padding: 15px;
    border-radius: 4px;
    font-family: monospace;
    font-size: 0.9em;
    overflow-x: auto;
    border: 1px solid #ddd;
}

.unterthemen-liste {
    margin-left: 20px;
    color: #666;
}

.unterthemen-liste li {
    margin-bottom: 5px;
}

.thema-count {
    font-size: 0.9em;
    color: #777;
    font-weight: normal;
}

/* Responsive Design für sehr große Bildschirme */
@media (min-width: 1400px) {
    .main-content {
        padding: 40px;
    }
}

/* Responsive Design für mobile Geräte */
@media (max-width: 1024px) {
    .container {
        flex-direction: column;
        padding: 10px;
        position: static;
        width: 100%;
    }
    
    .sidebar {
        width: 100%;
        min-height: auto;
        border-radius: 8px;
        margin-bottom: 20px;
        position: static !important;
        left: auto !important;
        right: auto !important;
        top: auto !important;
    }
    
    .sidebar:first-of-type {
        padding-left: 15px;
        padding-right: 15px;
        border-right: none;
        border-bottom: 1px solid #e0e0e0;
    }
    
    .sidebar:last-of-type {
        padding-left: 15px;
        padding-right: 15px;
        border-left: none;
        border-top: 1px solid #e0e0e0;
    }
    
    .main-content {
        width: 100%;
        margin: 0;
        border-radius: 8px;
        min-height: auto;
        margin-left: 0;
        margin-right: 0;
    }
}

@media (max-width: 768px) {
    .thema-header {
        padding: 10px;
        font-size: 0.85em;
    }
    
    .unterthemen-list li {
        padding: 6px 12px 6px 25px;
        font-size: 0.8em;
    }
    
    .thema-arrow {
        font-size: 0.7em;
    }
    
    .sidebar {
        padding: 10px;
    }
    
    .main-content {
        padding: 20px;
    }
}