/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg-primary: #0a0a0b;
    --bg-secondary: #141416;
    --bg-tertiary: #1c1c1f;
    --accent-blue: #3b82f6;
    --accent-green: #22c55e;
    --accent-orange: #f97316;
    --accent-red: #ef4444;
    --text-primary: #f4f4f5;
    --text-secondary: #a1a1aa;
    --text-muted: #71717a;
    --border-color: #27272a;
    --border-focus: #3b82f6;
}

body {
    font-family: 'Noto Sans KR', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 3rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-green));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-top: 0.5rem;
}

/* Main Layout */
main {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.top-section {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 2rem;
}

@media (max-width: 900px) {
    .top-section {
        grid-template-columns: 1fr;
    }
}

/* Panel Styling */
.settings-panel,
.preview-panel,
.command-section,
.output-section {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
}

h2 {
    font-size: 1.1rem;
    font-weight: 500;
    margin-bottom: 1.25rem;
    color: var(--text-primary);
}

/* Settings Panel */
.setting-group {
    margin-bottom: 1.25rem;
}

.setting-group:last-child {
    margin-bottom: 0;
}

.setting-group label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.setting-group input,
.setting-group select {
    width: 100%;
    padding: 0.75rem 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.95rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.setting-group input:focus,
.setting-group select:focus {
    outline: none;
    border-color: var(--border-focus);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

.setting-group select {
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23a1a1aa' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 1rem center;
}

/* Preview Panel */
.preview-panel {
    display: flex;
    flex-direction: column;
}

.canvas-container {
    background: var(--bg-tertiary);
    border-radius: 8px;
    padding: 1rem;
    display: flex;
    justify-content: center;
    align-items: center;
    flex: 1;
    min-height: 300px;
}

#previewCanvas {
    background: var(--bg-primary);
    border-radius: 4px;
    max-width: 100%;
    height: auto;
}

.preview-info {
    display: flex;
    gap: 1.5rem;
    margin-top: 1rem;
    justify-content: center;
}

.legend {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.legend.start {
    color: var(--accent-green);
}

.legend.end {
    color: var(--accent-orange);
}

/* Command Section */
.command-help {
    background: var(--bg-tertiary);
    border-radius: 8px;
    padding: 1rem 1.25rem;
    margin-bottom: 1rem;
    font-size: 0.9rem;
}

.command-help p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.command-help ul {
    list-style: none;
    margin: 0.75rem 0;
}

.command-help li {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    padding-left: 1rem;
    position: relative;
}

.command-help li::before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--text-muted);
}

.command-help code {
    font-family: 'JetBrains Mono', monospace;
    background: var(--bg-secondary);
    padding: 0.15rem 0.4rem;
    border-radius: 4px;
    font-size: 0.85rem;
    color: var(--accent-blue);
}

.command-help .note {
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-top: 0.75rem;
    margin-bottom: 0;
}

#commandInput {
    width: 100%;
    min-height: 200px;
    padding: 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.95rem;
    line-height: 1.8;
    resize: vertical;
    transition: border-color 0.2s, box-shadow 0.2s;
}

#commandInput:focus {
    outline: none;
    border-color: var(--border-focus);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

#commandInput.error {
    border-color: var(--accent-red);
    box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.15);
}

.error-message {
    color: var(--accent-red);
    font-size: 0.9rem;
    margin-top: 0.75rem;
    min-height: 1.5rem;
}

/* Button Section */
.button-section {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.btn {
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 500;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    font-family: 'Noto Sans KR', sans-serif;
}

.btn-preview {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-preview:hover {
    background: var(--border-color);
    border-color: var(--text-muted);
}

.btn-generate {
    background: var(--accent-blue);
    color: white;
}

.btn-generate:hover {
    background: #2563eb;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.btn:active {
    transform: translateY(0);
}

/* Output Section */
.output-section {
    display: none;
}

.output-section.visible {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.code-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-color);
}

.code-header span {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.btn-copy {
    padding: 0.5rem 1rem;
    font-size: 0.85rem;
    font-weight: 500;
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s;
    font-family: 'Noto Sans KR', sans-serif;
}

.btn-copy:hover {
    background: var(--border-color);
}

.btn-copy.copied {
    background: var(--accent-green);
    border-color: var(--accent-green);
    color: white;
}

#codeOutput {
    background: var(--bg-tertiary);
    border-radius: 8px;
    padding: 1.25rem;
    overflow-x: auto;
    max-height: 500px;
    overflow-y: auto;
}

#codeOutput code {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    line-height: 1.7;
    color: var(--text-primary);
    white-space: pre;
}

/* Footer */
footer {
    text-align: center;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-tertiary);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}