:root {
    --accent: #5a10c1;
    --bg: #f4f5f8;
    --surface: #ffffff;
    --input-bg: var(--surface);
    --text: #1f2230;
    --muted: #6d7481;
    --border: #dee2e6;
}

body {
    color-scheme: light;
    background: var(--bg);
    color: var(--text);
    transition: background-color 0.25s ease, color 0.25s ease;
}

body[data-theme="dark"] {
    color-scheme: dark;
    --bg: #121523;
    --surface: #1f2432;
    --input-bg: #151a26;
    --text: #edf0f8;
    --muted: #b4bccb;
    --border: #343a4d;
}

[v-cloak] {
    display: none;
}

.app-accent {
    color: var(--accent);
}

.app-subtitle {
    color: var(--muted);
}

.page-nav .btn.active {
    background: var(--accent);
    border-color: var(--accent);
    color: #ffffff;
}

.app-card {
    border-radius: 0.75rem;
    border: 1px solid var(--border);
    background: var(--surface);
    overflow: hidden;
    transition: border-color 0.25s ease, background-color 0.25s ease;
}

.app-card-header {
    background: color-mix(in srgb, var(--accent) 12%, var(--surface));
    color: var(--text);
    border-bottom: 1px solid var(--border);
}

.app-card .card-body,
.app-card .form-label,
.app-card h2,
.app-card h5,
.app-card p,
.app-card span,
.app-card .small {
    color: var(--text);
}

.app-btn {
    background: var(--accent);
    color: #ffffff;
    border: none;
    transition: transform 0.2s ease, opacity 0.2s ease;
}

.app-btn:hover {
    transform: translateY(-1px);
    opacity: 0.95;
    color: #ffffff;
}

.theme-toggle-btn {
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 1000;
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    border-radius: 999px;
    padding: 0.4rem 0.9rem;
    font-size: 0.95rem;
    min-width: 118px;
    width: 118px;
    text-align: center;
    white-space: nowrap;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}

.theme-toggle-btn:hover {
    border-color: var(--accent);
}

.form-control,
.form-select,
.input-group-text {
    background-color: var(--input-bg);
    color: var(--text);
    border-color: var(--border);
}

.form-control::placeholder {
    color: var(--muted);
    opacity: 1;
}

.form-control:focus,
.form-select:focus {
    background-color: var(--input-bg);
    color: var(--text);
    border-color: var(--accent);
    box-shadow: 0 0 0 0.2rem rgba(90, 16, 193, 0.25);
}

body[data-theme="dark"] .form-select option {
    background-color: var(--input-bg);
    color: var(--text);
}

body[data-theme="dark"] .form-control:disabled,
body[data-theme="dark"] .form-select:disabled {
    background-color: var(--input-bg) !important;
    color: var(--muted) !important;
    opacity: 1;
    border-color: var(--border);
}

.afd-diagram {
    width: 100%;
    min-height: 380px;
    height: min(55vh, 520px);
    background: var(--surface);
    border-top: 1px solid var(--border);
}

.diagram-legend {
    color: var(--muted);
}

.diagram-legend .legend-swatch {
    display: inline-block;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    vertical-align: middle;
    margin-right: 0.25rem;
    border: 2px solid #333;
}

.diagram-legend .legend-initial {
    border-color: var(--accent);
    border-width: 3px;
}

.diagram-legend .legend-final {
    background: #d1e7dd;
    border-color: #198754;
    border-width: 3px;
}

.diagram-legend .legend-path {
    background: #fff3cd;
    border-color: #fd7e14;
}

.problem-panel {
    border-left: 4px solid var(--accent);
}

.transition-editor {
    min-height: 320px;
    font-family: Consolas, "Liberation Mono", monospace;
}

.transition-builder {
    max-height: 360px;
    overflow-y: auto;
    padding-right: 0.1rem;
}

.transition-row {
    border: 1px solid var(--border);
    border-radius: 0.65rem;
    background: color-mix(in srgb, var(--surface) 94%, var(--accent));
}

.transition-row .form-label {
    white-space: nowrap;
}

.transition-row .form-select {
    font-size: 0.95rem;
    padding-right: 1.9rem;
    background-size: 0.7rem 0.55rem;
}

.stack-chip {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    border: 1px solid var(--border);
    border-radius: 999px;
    padding: 0.25rem 0.6rem;
    background: color-mix(in srgb, var(--surface) 82%, var(--accent));
}

.trace-card {
    border: 1px solid var(--border);
    border-radius: 0.75rem;
    background: color-mix(in srgb, var(--surface) 90%, var(--accent));
}

.trace-card pre {
    margin: 0;
    white-space: pre-wrap;
    word-break: break-word;
    color: var(--text);
}

.trace-table {
    font-size: 0.95rem;
}