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

:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --bg-color: #f7fafc;
    --card-bg: #ffffff;
    --text-primary: #2d3748;
    --text-secondary: #718096;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1), 0 2px 4px rgba(0,0,0,0.06);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.12), 0 4px 10px rgba(0,0,0,0.08);
    --radius: 12px;
    --radius-sm: 8px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    padding: 40px 0;
    position: relative;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 10px;
}

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

.lang-switcher {
    position: absolute;
    top: 20px;
    right: 20px;
    display: flex;
    gap: 8px;
}

.lang-btn {
    padding: 6px 12px;
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.9rem;
}

.lang-btn:hover {
    border-color: var(--primary-color);
    transform: translateY(-1px);
}

.lang-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

main {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
}

@media (max-width: 968px) {
    main {
        grid-template-columns: 1fr;
    }
    
    .lang-switcher {
        position: static;
        justify-content: center;
        margin-top: 20px;
    }
}

.gradient-preview-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.gradient-preview {
    width: 100%;
    height: 400px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
    transition: var(--transition);
}

.preset-gradients {
    background: var(--card-bg);
    padding: 20px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
}

.preset-gradients h3 {
    margin-bottom: 15px;
    color: var(--text-primary);
    font-size: 1.1rem;
}

.preset-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(60px, 1fr));
    gap: 10px;
}

.preset-item {
    height: 60px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.preset-item:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

.controls-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.gradient-type-selector {
    display: flex;
    gap: 10px;
    background: var(--card-bg);
    padding: 20px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
}

.type-btn {
    flex: 1;
    padding: 12px 20px;
    border: 2px solid var(--border-color);
    background: var(--card-bg);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    font-size: 1rem;
    font-weight: 500;
}

.type-btn:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.type-btn.active {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-color: transparent;
}

.gradient-controls {
    background: var(--card-bg);
    padding: 20px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
}

.control-group {
    margin-bottom: 25px;
}

.control-group label {
    display: block;
    margin-bottom: 10px;
    font-weight: 500;
    color: var(--text-primary);
}

.angle-input-group {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 15px;
}

#angleSlider {
    flex: 1;
    height: 6px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--border-color);
    border-radius: 3px;
    outline: none;
}

#angleSlider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    cursor: pointer;
    box-shadow: var(--shadow-sm);
}

#angleSlider::-moz-range-thumb {
    width: 20px;
    height: 20px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    cursor: pointer;
    box-shadow: var(--shadow-sm);
}

#angleInput {
    width: 70px;
    padding: 8px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    text-align: center;
}

.angle-presets {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 8px;
}

.angle-preset {
    padding: 10px;
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    font-size: 1.2rem;
}

.angle-preset:hover {
    border-color: var(--primary-color);
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.1), rgba(118, 75, 162, 0.1));
}

#shapeSelect {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    background: var(--card-bg);
}

.color-stops-section {
    margin-top: 20px;
}

.color-stops-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.color-stops-header h3 {
    font-size: 1.1rem;
    color: var(--text-primary);
}

.add-color-btn {
    padding: 8px 16px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
}

.add-color-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.color-stops {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.color-stop {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 15px;
    background: var(--bg-color);
    border-radius: var(--radius-sm);
}

.color-input {
    width: 50px;
    height: 50px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
}

.position-control {
    flex: 1;
    display: flex;
    align-items: center;
    gap: 10px;
}

.position-slider {
    flex: 1;
    height: 6px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--border-color);
    border-radius: 3px;
    outline: none;
}

.position-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
}

.position-slider::-moz-range-thumb {
    width: 16px;
    height: 16px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
}

.position-input {
    width: 60px;
    padding: 6px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    text-align: center;
}

.remove-btn {
    padding: 8px 12px;
    background: #ef4444;
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
}

.remove-btn:hover {
    background: #dc2626;
}

.output-section {
    background: var(--card-bg);
    padding: 20px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
}

.output-section h3 {
    margin-bottom: 15px;
    color: var(--text-primary);
}

.code-output {
    position: relative;
    background: #1a202c;
    border-radius: var(--radius-sm);
    padding: 20px;
    margin-bottom: 15px;
}

#cssOutput {
    color: #68d391;
    font-family: 'Courier New', monospace;
    font-size: 0.95rem;
    line-height: 1.6;
    white-space: pre-wrap;
    word-break: break-all;
}

.copy-btn {
    position: absolute;
    top: 10px;
    right: 10px;
    padding: 8px 16px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
}

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

.code-format label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
}

.code-format input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

.actions {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
}

.action-btn {
    padding: 12px 20px;
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
}

.action-btn:hover {
    border-color: var(--primary-color);
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.1), rgba(118, 75, 162, 0.1));
    transform: translateY(-2px);
}

footer {
    text-align: center;
    padding: 40px 0;
    color: var(--text-secondary);
}

@media (max-width: 640px) {
    h1 {
        font-size: 2rem;
    }
    
    .actions {
        grid-template-columns: 1fr;
    }
    
    .angle-presets {
        grid-template-columns: repeat(4, 1fr);
    }
}