:root {
    --bg: #1e1f22;
    --panel: #2a2c30;
    --panel-2: #34373c;
    --border: #3f4248;
    --text: #e6e7e9;
    --text-dim: #a8acb3;
    --accent: #d6a04a;
    --accent-hover: #e0b566;
    --danger: #c05a3a;
    --ground: #5a5d63;
}

* { box-sizing: border-box; }

html, body {
    margin: 0;
    padding: 0;
    height: 100%;
    background: var(--bg);
    color: var(--text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    font-size: 13px;
    overflow: hidden;
}

body {
    display: flex;
    flex-direction: column;
}

.topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 16px;
    background: var(--panel);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}

.topbar h1 {
    margin: 0;
    font-size: 15px;
    font-weight: 600;
    color: var(--accent);
    letter-spacing: 0.2px;
}

.topbar-actions {
    display: flex;
    gap: 8px;
}

.topbar-actions button {
    padding: 6px 14px;
    background: var(--panel-2);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: 4px;
    cursor: pointer;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.3px;
    transition: background 0.15s, border-color 0.15s;
}

.topbar-actions button:hover {
    background: var(--accent);
    color: #1a1a1a;
    border-color: var(--accent);
}

#btn-help {
    width: 28px;
    height: 28px;
    padding: 0;
    border-radius: 50%;
    font-size: 14px;
}

.topbar-sep {
    width: 1px;
    height: 22px;
    background: var(--border);
    align-self: center;
}

.layout {
    display: flex;
    flex: 1 1 auto;
    min-height: 0;
}

.sidebar {
    width: 240px;
    flex-shrink: 0;
    background: var(--panel);
    border-right: 1px solid var(--border);
    padding: 12px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.panel {
    background: var(--panel-2);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 10px 12px;
}

.panel h2 {
    margin: 0 0 8px 0;
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-dim);
    font-weight: 600;
}

.radio {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 4px 0;
    cursor: pointer;
    user-select: none;
}

.radio input[type="radio"] {
    accent-color: var(--accent);
}

.field {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 8px;
    gap: 8px;
}

.field:last-child {
    margin-bottom: 0;
}

.field label {
    font-size: 12px;
    color: var(--text-dim);
    flex: 1 1 auto;
}

.field input[type="number"] {
    width: 80px;
    padding: 4px 6px;
    background: var(--bg);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: 3px;
    font-size: 12px;
    font-family: inherit;
}

.field input[type="number"]:focus {
    outline: none;
    border-color: var(--accent);
}

.readout {
    margin-top: 10px;
    padding-top: 8px;
    border-top: 1px solid var(--border);
    font-size: 11px;
    color: var(--text-dim);
}

.readout span {
    color: var(--accent);
    font-weight: 600;
    font-family: ui-monospace, "Cascadia Code", monospace;
}

.panel-footer {
    margin-top: auto;
}

.panel-footer .hint {
    margin: 0;
    font-size: 11px;
    color: var(--text-dim);
    line-height: 1.5;
}

.panel-footer code {
    background: var(--bg);
    color: var(--accent);
    padding: 1px 4px;
    border-radius: 2px;
    font-size: 10px;
}

.viewports {
    flex: 1 1 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    min-width: 0;
    min-height: 0;
}

@media (max-width: 900px) {
    .layout {
        flex-direction: column;
    }
    .sidebar {
        width: 100%;
        max-height: 42vh;
        border-right: none;
        border-bottom: 1px solid var(--border);
    }
    .viewports {
        grid-template-columns: 1fr;
        grid-template-rows: 1fr 1fr;
        min-height: 50vh;
    }
}

.viewport {
    position: relative;
    border-right: 1px solid var(--border);
    background: var(--bg);
    display: flex;
    flex-direction: column;
    min-width: 0;
    min-height: 0;
}

.viewport:last-child {
    border-right: none;
}

.viewport-title {
    position: absolute;
    top: 8px;
    left: 8px;
    padding: 3px 8px;
    background: rgba(0, 0, 0, 0.5);
    color: var(--text-dim);
    font-size: 11px;
    border-radius: 3px;
    z-index: 5;
    pointer-events: none;
    letter-spacing: 0.3px;
}

.viewport.active {
    outline: 2px solid var(--accent);
    outline-offset: -2px;
}

.view2d-container,
.view3d-container {
    flex: 1 1 auto;
    width: 100%;
    height: 100%;
    overflow: hidden;
    min-width: 0;
    min-height: 0;
}

.view2d-container svg {
    width: 100%;
    height: 100%;
    display: block;
}

.view3d-container canvas {
    display: block;
    width: 100% !important;
    height: 100% !important;
}

.toast {
    position: fixed;
    bottom: 16px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--accent);
    color: #1a1a1a;
    padding: 8px 16px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 600;
    z-index: 100;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
    animation: toast-in 0.2s ease-out;
}

.toast.error {
    background: var(--danger);
    color: #fff;
}

@keyframes toast-in {
    from { opacity: 0; transform: translate(-50%, 10px); }
    to   { opacity: 1; transform: translate(-50%, 0); }
}

.help-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.65);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 200;
    backdrop-filter: blur(2px);
}

.help-overlay[hidden] {
    display: none;
}

.help-modal {
    width: min(640px, 92vw);
    max-height: 85vh;
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: 8px;
    display: flex;
    flex-direction: column;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.6);
    overflow: hidden;
}

.help-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 18px;
    background: var(--panel-2);
    border-bottom: 1px solid var(--border);
}

.help-header h2 {
    margin: 0;
    font-size: 15px;
    color: var(--accent);
}

#btn-help-close {
    background: transparent;
    color: var(--text-dim);
    border: none;
    font-size: 22px;
    line-height: 1;
    cursor: pointer;
    padding: 0 6px;
}

#btn-help-close:hover {
    color: var(--text);
}

.help-body {
    padding: 16px 22px 20px;
    overflow-y: auto;
    line-height: 1.6;
    color: var(--text);
}

.help-body h3 {
    margin: 16px 0 6px;
    font-size: 13px;
    color: var(--accent);
    border-bottom: 1px solid var(--border);
    padding-bottom: 4px;
}

.help-body p, .help-body ul {
    margin: 6px 0;
    font-size: 12.5px;
}

.help-body ul {
    padding-left: 22px;
}

.help-body li {
    margin: 3px 0;
}

.help-body code {
    background: var(--bg);
    color: var(--accent);
    padding: 1px 6px;
    border-radius: 3px;
    font-family: ui-monospace, "Cascadia Code", Consolas, monospace;
    font-size: 11.5px;
}

.help-body pre {
    background: var(--bg);
    color: var(--text);
    padding: 8px 12px;
    border-radius: 4px;
    font-family: ui-monospace, "Cascadia Code", Consolas, monospace;
    font-size: 11.5px;
    overflow-x: auto;
    margin: 6px 0;
}

.help-body strong {
    color: var(--accent);
}

.help-body em {
    font-style: italic;
    color: var(--text-dim);
}

.topbar-home {
    color: inherit;
    text-decoration: none;
}

.topbar-home:hover {
    color: var(--accent-hover);
}

.hint-inline {
    margin: 0;
    font-size: 10.5px;
    color: var(--text-dim);
    line-height: 1.45;
}

.view2d-tabs {
    position: absolute;
    top: 36px;
    left: 8px;
    right: 8px;
    z-index: 6;
    display: flex;
    gap: 4px;
}

.view2d-tabs button {
    padding: 4px 10px;
    font-size: 10px;
    background: var(--panel-2);
    color: var(--text-dim);
    border: 1px solid var(--border);
    border-radius: 3px;
    cursor: pointer;
}

.view2d-tabs button.active {
    color: #1a1a1a;
    background: var(--accent);
    border-color: var(--accent);
}

.view2d-container {
    position: relative;
    padding-top: 32px;
}

.hub-page {
    overflow: auto;
}

.hub-page .layout,
.hub-page body {
    overflow: auto;
}

.hub-main {
    padding: 20px 24px 40px;
    max-width: 960px;
    margin: 0 auto;
}

.hub-intro {
    color: var(--text-dim);
    line-height: 1.6;
    margin-bottom: 20px;
}

.hub-card {
    display: block;
    padding: 16px 18px;
    background: var(--panel-2);
    border: 1px solid var(--border);
    border-radius: 8px;
    text-decoration: none;
    color: var(--text);
    transition: border-color 0.15s, transform 0.15s;
}

.hub-card:hover {
    border-color: var(--accent);
    transform: translateY(-2px);
}

.hub-card-primary {
    grid-column: 1 / -1;
    border-color: var(--accent);
    background: linear-gradient(135deg, var(--panel-2) 0%, #32362e 100%);
}

.hub-card h2 {
    margin: 0 0 8px;
    font-size: 14px;
    color: var(--accent);
}

.hub-card p {
    margin: 0 0 10px;
    font-size: 12px;
    color: var(--text-dim);
    line-height: 1.5;
}

.hub-tags {
    font-size: 10px;
    font-weight: 600;
    letter-spacing: 0.4px;
    color: var(--accent);
}