:root {
    --bg-primary: #0b0f19;
    --bg-secondary: #151d30;
    --accent: #00f2fe;
    --accent-purple: #4facfe;
    --text-main: #f1f5f9;
    --text-muted: #94a3b8;
    --border: #24355a;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-main);
    height: 100vh;
    overflow: hidden;
}

.app-container {
    display: flex;
    height: 100vh;
}

/* Sidebar */
.sidebar {
    width: 280px;
    background-color: var(--bg-secondary);
    border-right: 1px solid var(--border);
    padding: 2rem 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.logo h2 {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 1px;
}

.logo h2 span {
    background: linear-gradient(135deg, var(--accent), var(--accent-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.categories h3 {
    font-size: 0.8rem;
    text-transform: uppercase;
    color: var(--text-muted);
    letter-spacing: 1.5px;
    margin-bottom: 1rem;
}

.categories ul {
    list-style: none;
}

.categories li {
    margin-bottom: 0.5rem;
}

.categories a {
    color: var(--text-muted);
    text-decoration: none;
    padding: 0.75rem 1rem;
    display: block;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.categories a:hover, .categories a.active {
    background-color: var(--border);
    color: var(--accent);
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 2rem;
    gap: 2rem;
    overflow-y: auto;
}

/* AI Section Chat */
.ai-section {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    height: 450px;
}

.chat-header h3 {
    color: var(--accent);
}

.chat-header p {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.chat-box {
    flex: 1;
    overflow-y: auto;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1rem;
    background-color: rgba(11, 15, 25, 0.5);
    margin-bottom: 1rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.message {
    padding: 0.75rem 1rem;
    border-radius: 8px;
    max-width: 80%;
    line-height: 1.5;
}

.system-message {
    background-color: var(--border);
    color: var(--text-main);
    align-self: center;
    text-align: center;
    font-size: 0.9rem;
}

.user-message {
    background-color: var(--accent-purple);
    color: #fff;
    align-self: flex-end;
}

.ai-message {
    background-color: var(--border);
    color: var(--text-main);
    align-self: flex-start;
    border-left: 4px solid var(--accent);
    white-space: pre-wrap;
}

.input-area {
    display: flex;
    gap: 1rem;
}

.input-area input {
    flex: 1;
    background-color: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 0.75rem 1rem;
    color: var(--text-main);
    outline: none;
}

.input-area input:focus {
    border-color: var(--accent);
}

.input-area button {
    background: linear-gradient(135deg, var(--accent), var(--accent-purple));
    border: none;
    border-radius: 8px;
    padding: 0.75rem 1.5rem;
    color: var(--bg-primary);
    font-weight: bold;
    cursor: pointer;
    transition: transform 0.2s;
}

.input-area button:hover {
    transform: scale(1.03);
}

/* Manuals Grid */
.manuals-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
}

.manual-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.25rem;
    transition: border-color 0.3s;
}

.manual-card:hover {
    border-color: var(--accent);
}

.manual-card h4 {
    margin-bottom: 0.5rem;
    color: var(--accent);
}

.manual-card p {
    font-size: 0.85rem;
    color: var(--text-muted);
    line-height: 1.4;
    margin-bottom: 1rem;
}

.tag {
    display: inline-block;
    font-size: 0.75rem;
    padding: 0.25rem 0.5rem;
    background-color: var(--border);
    border-radius: 4px;
    color: var(--accent-purple);
}