:root {
    --bg-color: #1e1e1e;
    --text-color: #d4d4d4;
    --sidebar-bg: #252526;
    --border-color: #333;
    --accent-color: #007acc;
    --success-color: #4CAF50;
    --cursor-color: #d4d4d4;
    --cursor-insert-color: #d4d4d4;
    --status-bg: #007acc;
    --status-fg: #ffffff;
    --font-family: 'Courier New', Courier, monospace;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    height: 100vh;
    display: flex;
    overflow: hidden;
}

#app-container {
    display: flex;
    width: 100%;
    height: 100%;
}

/* Sidebar Styling */
#sidebar {
    width: 350px;
    background-color: var(--sidebar-bg);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    padding: 20px;
}

#sidebar header {
    margin-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 10px;
}

#sidebar h1 {
    font-size: 1.5rem;
    color: var(--accent-color);
    margin-bottom: 5px;
}

#lesson-progress {
    font-size: 0.9rem;
    color: #888;
}

#lesson-content {
    flex-grow: 1;
    overflow-y: auto;
}

#lesson-title {
    font-size: 1.2rem;
    margin-bottom: 15px;
}

#lesson-text {
    line-height: 1.5;
    margin-bottom: 20px;
}

#lesson-text p {
    margin-bottom: 10px;
}

#lesson-text kbd {
    background-color: #333;
    border: 1px solid #555;
    border-radius: 3px;
    padding: 2px 5px;
    font-family: var(--font-family);
    font-size: 0.9em;
}

#lesson-goals-container h3 {
    font-size: 1rem;
    margin-bottom: 10px;
    color: #aaa;
}

#lesson-goals {
    list-style-type: none;
}

#lesson-goals li {
    padding: 8px 0;
    border-bottom: 1px dashed var(--border-color);
    display: flex;
    align-items: center;
}

#lesson-goals li::before {
    content: '○';
    margin-right: 10px;
    color: #888;
}

#lesson-goals li.completed::before {
    content: '●';
    color: var(--success-color);
}

#lesson-goals li.completed {
    color: #888;
    text-decoration: line-through;
}

#success-message {
    margin-top: 20px;
    padding: 15px;
    background-color: rgba(76, 175, 80, 0.1);
    border: 1px solid var(--success-color);
    border-radius: 5px;
    text-align: center;
}

#success-message p {
    font-weight: bold;
    color: var(--success-color);
    margin-bottom: 10px;
}

#next-lesson-btn {
    background-color: var(--success-color);
    color: white;
    border: none;
    padding: 8px 15px;
    border-radius: 3px;
    cursor: pointer;
    font-weight: bold;
}

#next-lesson-btn:hover {
    background-color: #45a049;
}

.hidden {
    display: none !important;
}

#sidebar footer {
    margin-top: 20px;
    font-size: 0.8rem;
    color: #666;
    text-align: center;
}

/* Terminal Area Styling */
#terminal-container {
    flex-grow: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
    background-color: #000;
}

#editor {
    width: 100%;
    max-width: 900px;
    height: 100%;
    max-height: 700px;
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 5px;
    display: flex;
    flex-direction: column;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
    font-family: var(--font-family);
    font-size: 16px;
    overflow: hidden;
}

#buffer-area {
    flex-grow: 1;
    padding: 10px;
    overflow-y: auto;
    position: relative;
    white-space: pre;
}

.buffer-line {
    min-height: 1.2em;
    position: relative;
}

/* Cursor Implementation */
.cursor {
    display: inline-block;
    background-color: var(--cursor-color);
    color: var(--bg-color) !important;
    animation: blink 1s step-end infinite;
}

.cursor.insert-mode {
    width: 2px;
    background-color: var(--cursor-insert-color);
    color: inherit !important;
    animation: blink 1s step-end infinite;
    position: absolute;
    /* Adjust based on character width if necessary, but inline block usually works */
}

@keyframes blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0; }
}

/* Status Line */
#status-line {
    display: flex;
    justify-content: space-between;
    background-color: var(--status-bg);
    color: var(--status-fg);
    padding: 2px 10px;
    font-size: 0.9em;
    font-weight: bold;
}

#mode-indicator {
    text-transform: uppercase;
}

/* Command Line */
#command-line {
    background-color: var(--bg-color);
    color: var(--text-color);
    padding: 2px 10px;
    font-size: 0.9em;
    border-top: 1px solid var(--border-color);
    display: flex;
}

#cmd-prompt {
    margin-right: 5px;
}

.cmd-cursor {
    display: inline-block;
    width: 8px;
    height: 1.2em;
    background-color: var(--cursor-color);
    animation: blink 1s step-end infinite;
    vertical-align: bottom;
}

/* Mode Selector */
#mode-selector {
    display: flex;
    gap: 5px;
    margin-bottom: 15px;
}

.mode-btn {
    flex: 1;
    background-color: #333;
    color: var(--text-color);
    border: 1px solid var(--border-color);
    padding: 5px 0;
    cursor: pointer;
    border-radius: 3px;
    font-size: 0.9em;
}

.mode-btn.active {
    background-color: var(--accent-color);
    color: #fff;
    font-weight: bold;
    border-color: var(--accent-color);
}

.mode-btn:hover:not(.active) {
    background-color: #444;
}

.sidebar-content {
    display: none;
}

.sidebar-content.active {
    display: block;
}

/* Golf Mode Specifics */
.golf-stats {
    background-color: rgba(0, 0, 0, 0.2);
    padding: 10px;
    border-radius: 5px;
    margin: 15px 0;
    border: 1px solid var(--border-color);
}

.golf-stats p {
    margin-bottom: 5px;
    font-family: var(--font-family);
}

#golf-target-container {
    margin-top: 15px;
}

#golf-target-text {
    background-color: #000;
    color: #888;
    padding: 10px;
    border-radius: 3px;
    border: 1px solid #444;
    white-space: pre-wrap;
    font-family: var(--font-family);
    font-size: 0.9em;
    min-height: 100px;
}

#golf-success-message {
    margin-top: 20px;
    padding: 15px;
    background-color: rgba(76, 175, 80, 0.1);
    border: 1px solid var(--success-color);
    border-radius: 5px;
    text-align: center;
}

#golf-success-message p {
    font-weight: bold;
    margin-bottom: 10px;
}

#golf-success-message button {
    display: block;
    width: 100%;
    margin-bottom: 5px;
    padding: 8px;
    border: none;
    border-radius: 3px;
    cursor: pointer;
    font-weight: bold;
}

#next-golf-btn {
    background-color: var(--success-color);
    color: white;
}

#retry-golf-btn {
    background-color: #555;
    color: white;
}

/* Tetris Mode Specifics */
.tetris-stats {
    background-color: rgba(0, 0, 0, 0.2);
    padding: 10px;
    border-radius: 5px;
    margin: 15px 0;
    border: 1px solid var(--border-color);
    font-family: var(--font-family);
    font-size: 1.2em;
    text-align: center;
}

#start-tetris-btn, #restart-tetris-btn {
    width: 100%;
    background-color: var(--accent-color);
    color: white;
    border: none;
    padding: 10px;
    border-radius: 3px;
    cursor: pointer;
    font-weight: bold;
    margin-top: 10px;
}

#tetris-game-over {
    margin-top: 20px;
    padding: 15px;
    background-color: rgba(244, 67, 54, 0.1);
    border: 1px solid #F44336;
    border-radius: 5px;
    text-align: center;
}

#tetris-game-over p {
    font-weight: bold;
    color: #F44336;
    font-size: 1.2em;
    margin-bottom: 15px;
}