:root {
    --sidebar-bg: #202123;
    --chat-bg: #343541;
    --input-bg: #40414f;
    --border-color: #4d4d4f;
    --text-primary: #ececf1;
    --text-secondary: #8e8ea0;
    --accent-color: #19c37d;
    --code-bg: #1e1e1e;
    --font-size-base: 13px;
    --font-size-sm: 11px;
    --font-size-xs: 10px;
}

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

html, body {
    height: 100%;
    overflow: hidden;
}

body {
    font-family: 'Inter', sans-serif;
    font-size: var(--font-size-base);
    background-color: var(--chat-bg);
    color: var(--text-primary);
    line-height: 1.5;
}

/* ── Layout ──────────────────────────────────────────────── */
.d-flex.h-100 {
    display: flex;
    height: 100vh;
}

/* ── Sidebar ─────────────────────────────────────────────── */
.sidebar {
    background-color: var(--sidebar-bg);
    width: 220px;
    height: 100vh;
    border-right: 1px solid var(--border-color);
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    padding: 10px;
    transition: left 0.3s ease;
    position: relative;
    z-index: 1000;
}

.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background-color: rgba(0,0,0,0.5);
    z-index: 999;
}
.sidebar-overlay.show { display: block; }

.new-chat-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 8px 10px;
    border-radius: 5px;
    width: 100%;
    text-align: left;
    font-size: var(--font-size-base);
    cursor: pointer;
    transition: background 0.2s;
}
.new-chat-btn:hover { background-color: rgba(255,255,255,0.08); }

/* ── Mode Selector ───────────────────────────────────────── */
.mode-selector {
    background-color: var(--input-bg);
    border-radius: 7px;
    padding: 3px;
    display: inline-flex;
}

.mode-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    padding: 5px 12px;
    border-radius: 5px;
    font-size: var(--font-size-base);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 5px;
    transition: all 0.2s;
}
.mode-btn.active {
    background-color: var(--sidebar-bg);
    color: var(--text-primary);
    box-shadow: 0 1px 3px rgba(0,0,0,0.3);
}

/* ── Chat Container ──────────────────────────────────────── */
.chat-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    height: 100vh;
    min-width: 0;
    position: relative;
}

/* ── Messages Area ───────────────────────────────────────── */
.messages-area {
    flex: 1;
    overflow-y: auto;
    padding: 12px 16px 8px;
    scroll-behavior: smooth;
}

.message {
    padding: 10px 12px;
    display: flex;
    gap: 10px;
    animation: fadeIn 0.25s ease;
}
.message.user      { background-color: var(--chat-bg); }
.message.assistant { background-color: #444654; }

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(6px); }
    to   { opacity: 1; transform: translateY(0); }
}

.message-wrapper {
    max-width: 760px;
    margin: 0 auto;
    width: 100%;
    display: flex;
    gap: 10px;
}

.avatar {
    width: 24px;
    height: 24px;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    flex-shrink: 0;
    font-size: var(--font-size-xs);
}
.avatar.user      { background-color: #5436da; color: #fff; }
.avatar.assistant { background-color: var(--accent-color); color: #fff; }

.message-content {
    flex: 1;
    line-height: 1.55;
    min-width: 0;
    font-size: var(--font-size-base);
    color: var(--text-primary);
}
.message.user .message-content {
    white-space: pre-wrap;
    word-break: break-word;
}

/* ── Markdown ────────────────────────────────────────────── */
.message-content h1 { font-size: 1.15em; margin: 1em 0 0.3em; }
.message-content h2 { font-size: 1.05em; margin: 0.9em 0 0.3em; }
.message-content h3,
.message-content h4,
.message-content h5,
.message-content h6 { font-size: 1em; margin: 0.8em 0 0.3em; }

.message-content p          { margin-bottom: 0.6em; }
.message-content ul,
.message-content ol         { margin-bottom: 0.6em; padding-left: 1.4em; }
.message-content li         { margin-bottom: 0.2em; }
.message-content strong     { font-weight: 600; color: #fff; }

.message-content code {
    font-family: 'JetBrains Mono', monospace;
    background-color: rgba(255,255,255,0.1);
    padding: 1px 5px;
    border-radius: 3px;
    font-size: 0.88em;
}
.message-content pre {
    background-color: var(--code-bg);
    border-radius: 6px;
    padding: 10px 12px;
    overflow-x: auto;
    margin: 0.6em 0;
}
.message-content pre code {
    background: transparent;
    padding: 0;
    font-size: 0.82rem;
    line-height: 1.45;
}

/* ── Code Block Header ───────────────────────────────────── */
.code-block-wrapper { margin: 0.6em 0; }

.code-header {
    background-color: #2d2d2d;
    padding: 5px 12px;
    border-radius: 6px 6px 0 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    border-bottom: 1px solid #3d3d3d;
}
.code-header + pre { margin-top: 0; border-radius: 0 0 6px 6px; }

.copy-code-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: var(--font-size-sm);
    display: flex;
    align-items: center;
    gap: 3px;
    transition: color 0.2s;
}
.copy-code-btn:hover { color: var(--text-primary); }

/* ── Input Area ──────────────────────────────────────────── */
.input-container {
    width: 100%;
    padding: 0;
    flex-shrink: 0;
}

.input-wrapper {
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    border-bottom: none;
    border-left: none;
    border-right: none;
    border-radius: 0;
    padding: 8px 10px 6px;
}

.form-control {
    background: transparent;
    border: none;
    color: var(--text-primary);
    resize: none;
    max-height: 160px;
    box-shadow: none !important;
    font-size: var(--font-size-base);
    padding: 2px 4px;
    line-height: 1.5;
}
.form-control:focus {
    background: transparent;
    color: var(--text-primary);
    outline: none;
    box-shadow: none !important;
}
.form-control::placeholder { color: var(--text-secondary); font-size: var(--font-size-base); }

.send-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    padding: 5px 7px;
    transition: all 0.2s;
    cursor: pointer;
    line-height: 1;
}
.send-btn:hover:not(:disabled) { color: var(--text-primary); transform: scale(1.1); }
.send-btn:disabled { opacity: 0.3; cursor: not-allowed; }

.input-disclaimer {
    text-align: center;
    padding: 3px 0 4px;
    background-color: var(--input-bg);
    font-size: var(--font-size-xs);
    color: var(--text-secondary);
}

/* ── File Upload ─────────────────────────────────────────── */
.file-preview {
    margin-top: 6px;
    padding-top: 6px;
    border-top: 1px solid var(--border-color);
}
.file-info {
    display: flex;
    align-items: center;
    gap: 6px;
    background-color: rgba(255,255,255,0.08);
    padding: 5px 10px;
    border-radius: 5px;
    font-size: var(--font-size-sm);
}
.file-info i { color: var(--accent-color); }
.remove-file-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    margin-left: auto;
    padding: 0;
    display: flex;
    align-items: center;
}
.remove-file-btn:hover { color: var(--text-primary); }

.file-message {
    background-color: rgba(255,255,255,0.04);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 8px 10px;
    margin-bottom: 8px;
    font-size: var(--font-size-sm);
}
.file-message img {
    max-width: 100%;
    max-height: 220px;
    border-radius: 4px;
    display: block;
    margin: 6px 0;
}

/* ── Image Generation ────────────────────────────────────── */
.image-container {
    margin-top: 10px;
    border-radius: 6px;
    overflow: hidden;
    background-color: var(--code-bg);
}
.generated-image {
    width: 100%;
    max-width: 480px;
    height: auto;
    display: block;
    margin: 0 auto;
}
.image-prompt {
    font-style: italic;
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
    padding: 8px 10px;
    background-color: rgba(0,0,0,0.2);
    border-top: 1px solid var(--border-color);
}
.image-prompt i { color: var(--accent-color); margin-right: 5px; }

/* ── Math / Diagrams ─────────────────────────────────────── */
.math-diagram {
    background-color: var(--code-bg);
    border-radius: 6px;
    padding: 10px;
    margin: 8px 0;
    text-align: center;
}
.math-diagram svg { max-width: 100%; height: auto; }

.mjx-chtml {
    font-size: 1em !important;
    color: var(--text-primary) !important;
}

/* ── Typing Indicator ────────────────────────────────────── */
.typing-indicator { display: flex; gap: 4px; padding: 8px 0; }
.typing-dot {
    width: 6px;
    height: 6px;
    background-color: var(--text-secondary);
    border-radius: 50%;
    animation: typing 1.4s infinite;
}
.typing-dot:nth-child(2) { animation-delay: 0.2s; }
.typing-dot:nth-child(3) { animation-delay: 0.4s; }
@keyframes typing {
    0%, 60%, 100% { transform: translateY(0); }
    30%           { transform: translateY(-6px); }
}

/* ── Empty State ─────────────────────────────────────────── */
.empty-state {
    text-align: center;
    padding: 24px 16px;
    color: var(--text-secondary);
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}
.empty-state h2 {
    color: var(--text-primary);
    font-size: 1.25rem;
    margin-bottom: 6px;
}
.empty-state p { font-size: var(--font-size-base); }

.example-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 10px;
    margin-top: 20px;
    max-width: 680px;
    width: 100%;
}
.example-card {
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    border-radius: 7px;
    padding: 12px;
    cursor: pointer;
    transition: all 0.2s;
    text-align: left;
    font-size: var(--font-size-sm);
}
.example-card:hover {
    background-color: var(--sidebar-bg);
    transform: translateY(-2px);
    border-color: var(--accent-color);
}
.example-card i { font-size: 1.1rem; margin-bottom: 5px; color: var(--accent-color); display: block; }
.example-card h6 { font-size: var(--font-size-base); margin-bottom: 3px; }
.example-card small { font-size: var(--font-size-xs); color: var(--text-secondary); }

/* ── Tables ──────────────────────────────────────────────── */
.message-content table { width: 100%; border-collapse: collapse; margin: 0.6em 0; font-size: var(--font-size-sm); }
.message-content th,
.message-content td { border: 1px solid var(--border-color); padding: 5px 8px; text-align: left; }
.message-content th { background-color: rgba(255,255,255,0.05); font-weight: 600; }
.message-content tr:nth-child(even) { background-color: rgba(255,255,255,0.02); }

/* ── Blockquotes / Links ─────────────────────────────────── */
.message-content blockquote {
    border-left: 3px solid var(--accent-color);
    margin: 0.6em 0;
    padding-left: 12px;
    color: var(--text-secondary);
    font-style: italic;
    font-size: var(--font-size-sm);
}
.message-content a { color: var(--accent-color); text-decoration: none; }
.message-content a:hover { text-decoration: underline; }

/* ── Menu Toggle (mobile) ────────────────────────────────── */
.menu-toggle { display: none; }

/* ── Mode selector spacing ───────────────────────────────── */
.d-flex.justify-content-center.pt-4.pb-2 {
    padding-top: 8px !important;
    padding-bottom: 4px !important;
}

/* ── Scrollbar ───────────────────────────────────────────── */
::-webkit-scrollbar { width: 5px; height: 5px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border-color); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: #565869; }

/* ── Responsive ──────────────────────────────────────────── */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: -220px;
        z-index: 1000;
    }
    .sidebar.show { left: 0; }

    .menu-toggle {
        display: flex !important;
        align-items: center;
        justify-content: center;
        position: absolute;
        top: 8px;
        left: 8px;
        z-index: 100;
        background: transparent;
        border: none;
        color: var(--text-primary);
        font-size: 1.2rem;
        cursor: pointer;
    }

    .messages-area { padding-top: 48px; padding-left: 10px; padding-right: 10px; }

    .message { padding: 8px 6px; }

    .example-cards { grid-template-columns: 1fr 1fr; gap: 8px; }

    .generated-image { max-width: 100%; }

    .mode-btn { padding: 5px 8px; font-size: var(--font-size-sm); }
}

@media (max-width: 400px) {
    .example-cards { grid-template-columns: 1fr; }
}