:root {
    --bg-color: #0d1117;
    --panel-bg: #161b22;
    --text-primary: #c9d1d9;
    --text-secondary: #8b949e;
    --accent-color: #087ea4;
    --accent-hover: #0b93bf;
    --border-color: #30363d;
    --nav-hover: #1f2428;
    --card-bg: #0d1117;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.5;
    height: 100vh;
    overflow: hidden;
}

.back-btn {
    position: absolute;
    top: 15px;
    left: 20px;
    font-family: 'Inter', sans-serif;
    font-size: 0.85rem;
    font-weight: 500;
    color: #8b949e;
    background: var(--panel-bg);
    padding: 6px 14px;
    border-radius: 6px;
    text-decoration: none;
    border: 1px solid var(--border-color);
    z-index: 9999;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
    transition: all 0.2s;
}

.back-btn:hover {
    color: #fff;
    border-color: #8b949e;
    background: var(--nav-hover);
}

.split-container {
    display: flex;
    height: 100vh;
    width: 100vw;
}

/* Left Panel */
.left-panel {
    width: 350px;
    background-color: var(--panel-bg);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    height: 100%;
}

.header-section {
    padding: 60px 20px 20px 20px;
    border-bottom: 1px solid var(--border-color);
}

.header-section h1 {
    font-size: 1.3rem;
    color: #fff;
    margin-bottom: 5px;
    font-weight: 600;
}

.header-section p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 10px;
}

.version-badge {
    display: inline-block;
    font-family: 'Fira Code', monospace;
    font-size: 0.7rem;
    background: rgba(8, 126, 164, 0.15);
    color: var(--accent-color);
    padding: 4px 8px;
    border-radius: 4px;
    border: 1px solid rgba(8, 126, 164, 0.3);
}

.nav-container {
    flex-grow: 1;
    overflow-y: auto;
    padding: 10px 0;
}

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

.nav-category {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    padding: 15px 20px 5px 20px;
    font-weight: 600;
}

.nav-item {
    display: block;
    padding: 8px 20px 8px 30px;
    font-size: 0.9rem;
    color: var(--text-primary);
    cursor: pointer;
    text-decoration: none;
    transition: all 0.2s ease;
    border-left: 3px solid transparent;
}

.nav-item:hover {
    background-color: var(--nav-hover);
    color: #fff;
}

.nav-item.active {
    background-color: rgba(8, 126, 164, 0.1);
    color: var(--accent-color);
    border-left: 3px solid var(--accent-color);
    font-weight: 500;
}

/* Right Panel */
.right-panel {
    flex-grow: 1;
    background-color: var(--bg-color);
    overflow-y: auto;
    padding: 40px;
    position: relative;
    display: flex;
    justify-content: center;
}

.content-display {
    max-width: 900px;
    width: 100%;
}

.welcome-screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    text-align: center;
    color: var(--text-secondary);
    margin-top: 20vh;
}

.welcome-icon {
    color: var(--accent-color);
    margin-bottom: 20px;
    opacity: 0.8;
}

.welcome-screen h2 {
    color: #fff;
    font-size: 1.5rem;
}

/* Content Blocks */
.content-block {
    animation: fadeIn 0.3s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.content-block h1 {
    font-size: 2rem;
    color: #fff;
    margin-bottom: 10px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 15px;
}

.content-block .lead {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 30px;
}

.content-block h2 {
    font-size: 1.3rem;
    color: #fff;
    margin: 30px 0 15px 0;
}

.content-block h3 {
    font-size: 1.1rem;
    color: #c9d1d9;
    margin: 20px 0 10px 0;
}

.content-block p {
    margin-bottom: 15px;
}

.content-block code {
    font-family: 'Fira Code', monospace;
    background-color: rgba(110, 118, 129, 0.1);
    padding: 2px 5px;
    border-radius: 4px;
    font-size: 0.85rem;
    color: #e6edf3;
}

.content-block pre {
    background-color: var(--panel-bg);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 15px;
    overflow-x: auto;
    margin-bottom: 20px;
}

.content-block pre code {
    background-color: transparent;
    padding: 0;
    color: var(--accent-color);
    font-size: 0.85rem;
}

.info-box {
    background: rgba(48, 54, 61, 0.5);
    border-left: 4px solid var(--accent-color);
    padding: 15px 20px;
    border-radius: 0 6px 6px 0;
    margin: 20px 0;
}

.info-box.warning {
    border-left-color: #d29922;
    background: rgba(210, 153, 34, 0.1);
}

.info-box strong {
    display: block;
    color: #fff;
    margin-bottom: 5px;
}

.info-box.warning strong {
    color: #d29922;
}


/* Mobile Responsiveness */
@media (max-width: 768px) {
    body {
        overflow: auto;
        height: auto;
    }
    .split-container {
        flex-direction: column;
    }
    .left-panel {
        overflow-y: visible;
        padding-bottom: 2rem;
    }
    .content-wrapper {
        padding: 1.5rem;
    }
    .right-panel {
        min-height: 500px;
        padding: 1.5rem;
    }
    .header-section h1 {
        font-size: 2rem;
    }
    .terminal-window {
        height: 100%;
        min-height: 400px;
    }
}