:root {
    --bg-color: #f4f7f6;
    --panel-bg: #ffffff;
    --text-color: #333333;
    --accent-color: #007bff;
    --accent-hover: #0056b3;
    --border-color: #e0e0e0;
    --danger-color: #dc3545;
    --danger-hover: #c82333;
    --header-bg: #2c3e50;
    --header-text: #ffffff;
    --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --border-radius: 8px;
}

[data-theme="dark"] {
    --bg-color: #1a1a1a;
    --panel-bg: #2d2d2d;
    --text-color: #f0f0f0;
    --accent-color: #4da3ff;
    --accent-hover: #73b9ff;
    --border-color: #444444;
    --header-bg: #111111;
    --header-text: #ffffff;
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-color);
    height: 100vh;
    display: flex;
    flex-direction: column;
    overflow: hidden; /* Verhindert Scrollen der gesamten Seite, da Panels scrollen */
}

/* Navigationsleiste */
header {
    background-color: var(--header-bg);
    color: var(--header-text);
    padding: 10px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    z-index: 10;
}

.header-title-wrapper {
    display: flex;
    align-items: center;
    gap: 15px;
}

.header-logo {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid white;
}

header h1 {
    font-size: 1.5rem;
    margin: 0;
}

nav a {
    color: var(--header-text);
    text-decoration: none;
    margin-left: 15px;
    font-size: 1.1rem;
    padding: 5px 10px;
    border-radius: 4px;
    transition: background-color 0.3s;
}

nav a:hover, nav a.active {
    background-color: rgba(255, 255, 255, 0.2);
}

.btn-landing {
    background-color: var(--accent-color);
    color: white;
    border: none;
    padding: 8px 15px;
    border-radius: var(--border-radius);
    cursor: pointer;
    text-decoration: none;
    font-size: 1rem;
    margin-left: 20px;
}

.btn-landing:hover {
    background-color: var(--accent-hover);
}

/* Hauptlayout */
.container {
    display: flex;
    flex-direction: column;
    flex: 1;
    padding: 10px;
    gap: 10px;
    height: calc(100vh - 60px); /* Abzug für Header */
}

/* Oberer Bereich (Hilfe) */
.top-section {
    display: flex;
    flex: 1;
    gap: 10px;
    min-height: 0; /* Wichtig für flex-child scrolling */
    transition: all 0.3s ease;
}

.top-section.hidden {
    display: none;
}

.top-left {
    flex: 1; /* 1/4 der Breite */
    background: var(--panel-bg);
    border-radius: var(--border-radius);
    padding: 15px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    display: flex;
    flex-direction: column;
}

.top-right {
    flex: 3; /* 3/4 der Breite */
    background: var(--panel-bg);
    border-radius: var(--border-radius);
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    overflow: hidden;
}

/* Unterer Bereich (Eingabe / Ausgabe) */
.bottom-section {
    display: flex;
    flex: 1;
    gap: 10px;
    min-height: 0;
}

.bottom-left, .bottom-right {
    flex: 1; /* Jeweils 1/2 der Breite */
    background: var(--panel-bg);
    border-radius: var(--border-radius);
    padding: 15px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    display: flex;
    flex-direction: column;
}

h2 {
    font-size: 1.2rem;
    margin-bottom: 10px;
    color: var(--text-color);
}

select {
    width: 100%;
    padding: 10px;
    font-size: 1.1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    cursor: pointer;
    background-color: var(--panel-bg);
    color: var(--text-color);
}

textarea {
    flex: 1;
    width: 100%;
    padding: 10px;
    font-family: 'Courier New', Courier, monospace;
    font-size: 1.1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    resize: none;
    margin-bottom: 10px;
    background-color: var(--panel-bg);
    color: var(--text-color);
}

iframe {
    width: 100%;
    height: 100%;
    border: none;
}

.button-group {
    display: flex;
    gap: 10px;
    margin-top: 10px;
}

button {
    padding: 10px 20px;
    font-size: 1.1rem;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    background-color: var(--accent-color);
    color: white;
    transition: background-color 0.3s;
}

button:hover {
    background-color: var(--accent-hover);
}

button.btn-danger {
    background-color: var(--danger-color);
}

button.btn-danger:hover {
    background-color: var(--danger-hover);
}

/* Spezielle Anpassungen für CSS-Lernseite */
.split-textarea {
    display: flex;
    flex-direction: column;
    flex: 1;
    gap: 10px;
}

/* Spezielle Anpassungen für JS-Lernseite */
.console-output {
    flex: 1;
    background: #1e1e1e;
    color: #00ff00;
    font-family: 'Courier New', Courier, monospace;
    padding: 10px;
    border-radius: var(--border-radius);
    overflow-y: auto;
    margin-top: 10px;
    white-space: pre-wrap;
}

/* Responsives Design für kleinere Bildschirme */
@media (max-width: 900px) {
    body {
        overflow-y: auto;
        height: auto;
    }
    header {
        flex-direction: column;
        align-items: center;
        gap: 15px;
        text-align: center;
    }
    nav {
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        gap: 10px;
    }
    nav a, .btn-landing, #btnThemeToggle {
        margin-left: 0 !important;
        margin-right: 0 !important;
    }
    .container {
        height: auto;
        overflow: visible;
    }
    .top-section, .bottom-section {
        flex-direction: column;
        flex: none;
    }
    .top-left, .top-right, .bottom-left, .bottom-right {
        min-height: 400px;
    }
    .split-textarea {
        flex-direction: column;
    }
}