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

body {
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    background: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
}

header {
    text-align: center;
    color: white;
    margin-bottom: 30px;
}

header h1 {
    font-size: 2.8em;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
    background: linear-gradient(45deg, #ff6b6b, #4ecdc4);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

header p {
    font-size: 1.3em;
    opacity: 0.9;
    color: #e8f4f8;
}

.lesson-selector {
    background: rgba(255,255,255,0.1);
    padding: 25px;
    border-radius: 15px;
    margin-bottom: 30px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.2);
}

.lesson-selector h3 {
    color: white;
    margin-bottom: 20px;
    text-align: center;
    font-size: 1.2em;
}

.lesson-buttons {
    display: flex;
    justify-content: center;
    gap: 15px;
    flex-wrap: wrap;
}

.lesson-btn {
    padding: 10px 20px;
    border: 2px solid rgba(255,255,255,0.3);
    border-radius: 25px;
    background: transparent;
    color: white;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.95em;
    font-weight: 500;
}

.lesson-btn:hover {
    background: rgba(255,255,255,0.2);
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}

.lesson-btn.active {
    background: rgba(78, 205, 196, 0.3);
    border-color: #4ecdc4;
    color: #4ecdc4;
    box-shadow: 0 0 20px rgba(78, 205, 196, 0.3);
}

.main-content {
    display: flex;
    gap: 30px;
    align-items: flex-start;
    margin-bottom: 30px;
}

.left-panel {
    flex: 0 0 420px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.right-panel {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.terminal-container {
    background: #0d1117;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 15px 35px rgba(0,0,0,0.4);
    border: 1px solid #30363d;
}

.terminal-header {
    background: #21262d;
    padding: 12px 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid #30363d;
}

.terminal-controls {
    display: flex;
    gap: 8px;
}

.control {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.control.close {
    background: #ff5f57;
}

.control.minimize {
    background: #ffbd2e;
}

.control.maximize {
    background: #28ca42;
}

.terminal-title {
    color: #cccccc;
    font-size: 14px;
    font-weight: 600;
}

.terminal-info {
    color: #7d8590;
    font-size: 12px;
}

.terminal-body {
    background: #0d1117;
    color: #c9d1d9;
    padding: 24px;
    min-height: 350px;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 14px;
    line-height: 1.5;
}

#terminal-output {
    margin-bottom: 15px;
    white-space: pre-wrap;
}

.input-line {
    display: flex;
    align-items: center;
}

#prompt {
    color: #58a6ff;
    margin-right: 8px;
    user-select: none;
    font-weight: 500;
}

#command-input {
    background: transparent;
    border: none;
    color: #c9d1d9;
    font-family: inherit;
    font-size: inherit;
    outline: none;
    flex: 1;
    caret-color: #58a6ff;
}

.help-panel {
    background: rgba(255,255,255,0.1);
    border-radius: 15px;
    padding: 20px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.2);
}

.help-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.help-header h3 {
    color: white;
    font-size: 1.1em;
}

.git-status {
    display: flex;
    align-items: center;
    gap: 8px;
    background: rgba(0,0,0,0.3);
    padding: 5px 12px;
    border-radius: 15px;
    font-size: 0.85em;
}

#current-branch {
    color: #4ecdc4;
    font-weight: 600;
}

#git-status-indicator {
    color: #3fb950;
    font-size: 1.2em;
}

.help-content {
    color: white;
    line-height: 1.6;
    max-height: 300px;
    overflow-y: auto;
}

.command-example {
    background: rgba(0,0,0,0.3);
    padding: 12px;
    border-radius: 8px;
    margin: 10px 0;
    font-family: monospace;
    border-left: 3px solid #4ecdc4;
}

.command-example code {
    color: #58a6ff;
    font-weight: 500;
}

.command-item.completed {
    opacity: 0.7;
}

.command-item.completed .command-example {
    border-left-color: #3fb950;
    background: rgba(63, 185, 80, 0.1);
}

.progress-panel {
    background: rgba(255,255,255,0.1);
    border-radius: 15px;
    padding: 20px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.2);
}

.progress-panel h3 {
    color: white;
    margin-bottom: 15px;
    text-align: center;
    font-size: 1.1em;
}

.progress-bar {
    background: rgba(255,255,255,0.2);
    height: 22px;
    border-radius: 11px;
    overflow: hidden;
    margin-bottom: 10px;
    border: 1px solid rgba(255,255,255,0.1);
}

.progress-fill {
    background: linear-gradient(90deg, #4ecdc4, #3fb950);
    height: 100%;
    width: 0%;
    transition: width 0.5s ease;
    box-shadow: 0 0 10px rgba(78, 205, 196, 0.3);
}

#progress-text {
    color: white;
    text-align: center;
    font-size: 14px;
    font-weight: 500;
}

.git-visualization {
    background: rgba(255,255,255,0.1);
    border-radius: 15px;
    padding: 20px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.2);
}

.git-visualization h3 {
    color: white;
    margin-bottom: 15px;
    text-align: center;
    font-size: 1.1em;
}

.git-graph {
    background: rgba(0,0,0,0.3);
    border-radius: 8px;
    padding: 15px;
    min-height: 120px;
    font-family: monospace;
    font-size: 12px;
    color: #c9d1d9;
    overflow-x: auto;
}

.file-explorer {
    background: rgba(255,255,255,0.1);
    border-radius: 12px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.2);
    overflow: hidden;
}

.explorer-header {
    background: rgba(0,0,0,0.2);
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.explorer-header h3 {
    color: white;
    font-size: 1em;
}

.control-btn {
    background: rgba(255,255,255,0.2);
    border: none;
    color: white;
    padding: 5px 10px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.8em;
    transition: all 0.3s ease;
}

.control-btn:hover {
    background: rgba(255,255,255,0.3);
}

.file-tree {
    padding: 15px;
    color: white;
    font-family: monospace;
    font-size: 13px;
    line-height: 1.4;
    max-height: 200px;
    overflow-y: auto;
}

.file-item {
    padding: 2px 0;
    display: flex;
    align-items: center;
    gap: 8px;
}

.file-icon {
    width: 16px;
    text-align: center;
}

.file-status {
    margin-left: auto;
    font-size: 0.8em;
    padding: 2px 6px;
    border-radius: 3px;
}

.file-status.modified {
    background: rgba(255, 193, 7, 0.3);
    color: #ffc107;
}

.file-status.added {
    background: rgba(63, 185, 80, 0.3);
    color: #3fb950;
}

.file-status.deleted {
    background: rgba(248, 81, 73, 0.3);
    color: #f85149;
}

.bottom-panel {
    background: rgba(255,255,255,0.1);
    border-radius: 15px;
    padding: 25px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.2);
}

.git-commands-reference h3 {
    color: white;
    text-align: center;
    margin-bottom: 20px;
    font-size: 1.2em;
}

.commands-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.command-group h4 {
    color: #4ecdc4;
    margin-bottom: 10px;
    font-size: 1em;
}

.command-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.cmd {
    background: rgba(0,0,0,0.3);
    color: #58a6ff;
    padding: 4px 8px;
    border-radius: 4px;
    font-family: monospace;
    font-size: 0.85em;
    cursor: pointer;
    transition: all 0.3s ease;
    border: 1px solid rgba(88, 166, 255, 0.3);
}

.cmd:hover {
    background: rgba(88, 166, 255, 0.2);
    transform: translateY(-1px);
}

.output-line {
    margin-bottom: 6px;
}

.output-command {
    color: #58a6ff;
    font-weight: 500;
}

.output-result {
    color: #e6edf3;
}

.output-error {
    color: #f85149;
    font-weight: 500;
}

.output-success {
    color: #3fb950;
    font-weight: 500;
}

.output-warning {
    color: #ffc107;
    font-weight: 500;
}

.output-git-status {
    color: #4ecdc4;
}

.hint {
    background: rgba(78, 205, 196, 0.15);
    border-left: 4px solid #4ecdc4;
    padding: 12px;
    margin: 12px 0;
    border-radius: 0 8px 8px 0;
    backdrop-filter: blur(5px);
}

.hint-text {
    color: #c9d1d9;
}

.git-commit {
    display: inline-block;
    background: rgba(78, 205, 196, 0.2);
    color: #4ecdc4;
    padding: 2px 6px;
    border-radius: 3px;
    font-family: monospace;
    font-size: 0.9em;
}

.git-branch {
    display: inline-block;
    background: rgba(255, 107, 107, 0.2);
    color: #ff6b6b;
    padding: 2px 6px;
    border-radius: 3px;
    font-family: monospace;
    font-size: 0.9em;
}

@media (max-width: 1200px) {
    .left-panel {
        flex: 0 0 380px;
    }
    
    .commands-grid {
        grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    }
}

@media (max-width: 1024px) {
    .left-panel {
        flex: 0 0 350px;
    }
    
    .lesson-buttons {
        gap: 10px;
    }
    
    .lesson-btn {
        padding: 8px 16px;
        font-size: 0.9em;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    body {
        padding: 10px;
    }
    
    header h1 {
        font-size: 2.2em;
    }
    
    .lesson-buttons {
        flex-direction: column;
        align-items: center;
        gap: 8px;
    }
    
    .lesson-btn {
        width: 200px;
        text-align: center;
    }
    
    .main-content {
        flex-direction: column;
        gap: 20px;
    }
    
    .left-panel {
        flex: none;
        width: 100%;
        order: 2;
    }
    
    .right-panel {
        flex: none;
        width: 100%;
        order: 1;
    }
    
    .terminal-body {
        font-size: 12px;
        padding: 15px;
        min-height: 300px;
    }
    
    .help-content {
        max-height: 250px;
    }
    
    .commands-grid {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    .git-graph {
        font-size: 11px;
        min-height: 100px;
    }
}