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

:root {
    --primary-color: #4169E1;
    --primary-hover: #3457c9;
    --secondary-color: #6C7293;
    --background: #f7f8fc;
    --surface: #ffffff;
    --text-primary: #2c3e50;
    --text-secondary: #6c757d;
    --border-color: #e0e4e8;
    --success-color: #28a745;
    --warning-color: #ffc107;
    --danger-color: #dc3545;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.15);
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --transition: all 0.3s ease;
}

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

/* Navigation */
.nav {
    background-color: var(--surface);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-title svg {
    width: 28px;
    height: 28px;
}

.language-selector {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background-color: var(--surface);
    color: var(--text-primary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: var(--transition);
}

.language-selector:hover {
    border-color: var(--primary-color);
}

/* Container */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem;
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

/* Controls Section */
.controls-section {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 2rem;
}

.current-resolution {
    background-color: var(--surface);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    text-align: center;
}

.current-resolution h2 {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.resolution-display {
    font-size: 2rem;
    font-weight: 600;
    color: var(--primary-color);
}

.resolution-label {
    display: block;
    font-size: 1rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
}

.control-panel {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

/* Preset Section */
.preset-section, .custom-section, .url-section {
    background-color: var(--surface);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.preset-section h3, .custom-section h3, .url-section h3 {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.preset-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 0.75rem;
}

.preset-btn {
    background-color: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 0.75rem;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
}

.preset-btn:hover {
    border-color: var(--primary-color);
    background-color: rgba(65, 105, 225, 0.05);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.preset-btn.phone {
    border-left: 3px solid #28a745;
}

.preset-btn.tablet {
    border-left: 3px solid #ffc107;
}

.preset-btn.laptop,
.preset-btn.desktop {
    border-left: 3px solid #17a2b8;
}

.preset-name {
    display: block;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

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

/* Custom Section */
.custom-inputs {
    display: flex;
    gap: 1rem;
    align-items: flex-end;
}

.input-group {
    flex: 1;
}

.input-group label {
    display: block;
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.input-group input {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    transition: var(--transition);
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(65, 105, 225, 0.1);
}

.apply-btn, .load-btn {
    padding: 0.75rem 1.5rem;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.apply-btn:hover, .load-btn:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

/* URL Section */
.url-input-group {
    display: flex;
    gap: 1rem;
}

.url-input-group input {
    flex: 1;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    transition: var(--transition);
}

.url-input-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(65, 105, 225, 0.1);
}

/* Preview Section */
.preview-section {
    background-color: var(--surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: 1.5rem;
}

.preview-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.preview-header h2 {
    font-size: 1.3rem;
    color: var(--text-primary);
}

.preview-controls {
    display: flex;
    gap: 0.5rem;
}

.icon-btn {
    padding: 0.5rem;
    background-color: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon-btn:hover {
    border-color: var(--primary-color);
    background-color: rgba(65, 105, 225, 0.05);
}

.preview-container {
    background-color: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    min-height: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    position: relative;
    overflow: hidden;
}

.preview-frame {
    background-color: white;
    box-shadow: var(--shadow-lg);
    border-radius: var(--radius-sm);
    position: relative;
    overflow: hidden;
    transition: var(--transition);
}

.preview-iframe {
    border: none;
    display: none;
    background-color: white;
}

.preview-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 3rem;
    color: var(--text-secondary);
    text-align: center;
}

.preview-placeholder svg {
    opacity: 0.3;
    margin-bottom: 1rem;
}

.preview-info {
    margin-top: 1rem;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Info Section */
.info-section {
    background-color: var(--surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: 3rem;
    text-align: center;
}

.info-section h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.info-section > p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 3rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.feature-card {
    padding: 2rem;
    background-color: var(--background);
    border-radius: var(--radius-md);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.feature-card h3 {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Footer */
.footer {
    background-color: var(--surface);
    border-top: 1px solid var(--border-color);
    padding: 2rem;
    text-align: center;
    color: var(--text-secondary);
    margin-top: auto;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .controls-section {
        grid-template-columns: 1fr;
    }
    
    .current-resolution {
        max-width: 400px;
        margin: 0 auto;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }
    
    .nav-content {
        padding: 1rem;
    }
    
    .nav-title {
        font-size: 1.2rem;
    }
    
    .custom-inputs {
        flex-direction: column;
    }
    
    .url-input-group {
        flex-direction: column;
    }
    
    .feature-grid {
        grid-template-columns: 1fr;
    }
    
    .preset-grid {
        grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    }
}

/* Fullscreen Styles */
.preview-container:fullscreen {
    background-color: #000;
    padding: 0;
}

.preview-container:fullscreen .preview-frame {
    box-shadow: none;
    border-radius: 0;
}