:root {
    --bg: #0b0c0e;
    --bg-elev: #121316;
    --bg-panel: #16171b;
    --bg-input: #0e0f12;
    --border: #2a2c31;
    --border-strong: #3a3d44;
    --text: #f3f1ea;
    --text-dim: #9a9b94;
    --text-faint: #6b6d66;
    --accent: #d9a441;
    --accent-hover: #e8b65a;
    --accent-ink: #1a1406;
    --danger: #d4735a;
    --user-bg: #1d1f24;
    --assistant-bg: #14151a;
    --focus: #d9a441;
    --shadow: 0 18px 50px rgba(0, 0, 0, 0.45);
    --canvas-dark: #1a1b1f;
    --canvas-light: #ece7dc;
    --checker-dark-a: #22232a;
    --checker-dark-b: #191a1f;
    --checker-light-a: #f4f0e6;
    --checker-light-b: #e4dfd2;
    --radius: 10px;
    --font: "IBM Plex Sans", "Segoe UI", system-ui, sans-serif;
    --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
}

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

html,
body {
    height: 100%;
    background: var(--bg);
    color: var(--text);
    font-family: var(--font);
    line-height: 1.5;
}

body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

button,
textarea {
    font-family: inherit;
}

.app-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 0.85rem 1.15rem;
    border-bottom: 1px solid var(--border);
    background: var(--bg-elev);
    flex-shrink: 0;
}

.brand {
    display: flex;
    align-items: baseline;
    gap: 0.7rem;
    min-width: 0;
}

.brand h1 {
    font-size: 1.05rem;
    font-weight: 600;
    letter-spacing: 0.01em;
}

.brand .meta {
    color: var(--text-dim);
    font-size: 0.78rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.layout {
    flex: 1;
    display: grid;
    grid-template-columns: minmax(320px, 42%) minmax(0, 1fr);
    min-height: 0;
}

.chat-pane,
.preview-pane {
    min-height: 0;
    display: flex;
    flex-direction: column;
}

.chat-pane {
    border-right: 1px solid var(--border);
    background: var(--bg);
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 1rem 1.1rem 0.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.message {
    padding: 0.7rem 0.85rem;
    border-radius: var(--radius);
    max-width: 92%;
    border: 1px solid transparent;
}

.message p {
    white-space: pre-wrap;
    overflow-wrap: anywhere;
    margin: 0;
    font-size: 0.92rem;
}

.user-message {
    background: var(--user-bg);
    border-color: var(--border);
    align-self: flex-end;
}

.assistant-message {
    background: var(--assistant-bg);
    border-color: var(--border);
    align-self: flex-start;
}

.message-role {
    display: block;
    font-size: 0.68rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--text-faint);
    margin-bottom: 0.25rem;
    font-weight: 600;
}

.starters {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.45rem;
    padding: 0 1.1rem 0.75rem;
}

.starter {
    text-align: left;
    background: var(--bg-panel);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 0.55rem 0.65rem;
    font-size: 0.78rem;
    cursor: pointer;
    transition: border-color 0.15s, background 0.15s;
}

.starter:hover,
.starter:focus-visible {
    border-color: var(--accent);
    outline: none;
}

.starter strong {
    display: block;
    font-weight: 600;
    margin-bottom: 0.1rem;
}

.starter span {
    color: var(--text-dim);
    font-size: 0.72rem;
}

.composer {
    display: flex;
    gap: 0.5rem;
    padding: 0.75rem 1.1rem 1rem;
    border-top: 1px solid var(--border);
    background: var(--bg-elev);
}

#user-input {
flex: 1;
resize: none;
min-height: 48px;
max-height: 160px;
padding: 0.7rem 0.8rem;
border-radius: 8px;
border: 1px solid var(--border);
background: var(--bg-input);
color: var(--text);
font-size: 0.92rem;
}

#user-input:focus {
outline: 2px solid var(--focus);
outline-offset: 1px;
}

#send-button,
.tool-btn {
    border: 1px solid var(--border-strong);
    background: var(--bg-panel);
    color: var(--text);
    border-radius: 8px;
    padding: 0 0.9rem;
    cursor: pointer;
    font-size: 0.82rem;
    font-weight: 600;
    white-space: nowrap;
}

#send-button {
background: var(--accent);
color: var(--accent-ink);
border-color: transparent;
}

#send-button:hover:not(:disabled) {
background: var(--accent-hover);
}

#send-button:disabled,
.tool-btn:disabled {
    opacity: 0.45;
    cursor: not-allowed;
}

.tool-btn:hover:not(:disabled),
.tool-btn:focus-visible {
    border-color: var(--accent);
    outline: none;
}

.status-row {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0 1.1rem 0.55rem;
    min-height: 1.4rem;
    color: var(--text-dim);
    font-size: 0.78rem;
}

.status-row[hidden] {
    display: none;
}

.preview-pane {
    background: var(--bg-elev);
}

.preview-toolbar {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
    padding: 0.7rem 0.9rem;
    border-bottom: 1px solid var(--border);
    align-items: center;
}

.preview-toolbar .spacer {
    flex: 1;
}

.canvas-wrap {
    flex: 1;
    min-height: 220px;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.canvas-wrap.theme-dark {
    background:
    repeating-conic-gradient(
        var(--checker-dark-a) 0% 25%,
                             var(--checker-dark-b) 0% 50%
    )
    0 0 / 20px 20px;
}

.canvas-wrap.theme-light {
    background:
    repeating-conic-gradient(
        var(--checker-light-a) 0% 25%,
                             var(--checker-light-b) 0% 50%
    )
    0 0 / 20px 20px;
}

#preview-frame {
width: 100%;
height: 100%;
border: 0;
background: transparent;
pointer-events: none;
}

.canvas-empty {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 2rem;
    color: var(--text-dim);
    pointer-events: none;
}

.canvas-empty[hidden],
#preview-frame[hidden] {
display: none;
}

.source-panel {
    border-top: 1px solid var(--border);
    background: var(--bg);
    max-height: 38%;
    display: flex;
    flex-direction: column;
}

.source-panel[hidden] {
    display: none;
}

.source-toggle {
    width: 100%;
    text-align: left;
    background: transparent;
    border: 0;
    color: var(--text-dim);
    padding: 0.55rem 0.9rem;
    cursor: pointer;
    font-size: 0.75rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    font-weight: 600;
}

.source-body {
    margin: 0;
    padding: 0 0.9rem 0.85rem;
    overflow: auto;
    max-height: 220px;
    color: var(--text);
    font-family: var(--mono);
    font-size: 0.72rem;
    line-height: 1.45;
    white-space: pre-wrap;
    overflow-wrap: anywhere;
}

.source-panel.collapsed .source-body {
    display: none;
}

@media (max-width: 860px) {
    .layout {
        grid-template-columns: 1fr;
        grid-template-rows: minmax(42vh, 1fr) minmax(46vh, 1fr);
    }

    .chat-pane {
        border-right: 0;
        border-bottom: 1px solid var(--border);
    }

    .starters {
        grid-template-columns: 1fr;
    }

    .brand .meta {
        display: none;
    }
}