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

:root {
    --primary-color: #0066ff;
    --primary-hover: #0052cc;
    --success-color: #00b341;
    --error-color: #ff3333;
    --warning-color: #ffaa00;
    --bg-color: #f7f8fa;
    --card-bg: #ffffff;
    --text-primary: #172b4d;
    --text-secondary: #6b778c;
    --border-color: #dfe1e6;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.12);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.1);
    --radius: 8px;
    --radius-sm: 4px;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    width: 100%;
}

/* Header */
header {
    background: var(--card-bg);
    box-shadow: var(--shadow-sm);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

h1 {
    font-size: 1.5rem;
    font-weight: 600;
    background: linear-gradient(135deg, var(--primary-color), #00b8ff);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.lang-selector {
    display: flex;
    gap: 0.5rem;
}

.lang-btn {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.2s;
    font-size: 0.875rem;
}

.lang-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

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

/* Main Content */
main {
    flex: 1;
    padding: 2rem 0;
}

/* Tabs */
.tabs {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    border-bottom: 2px solid var(--border-color);
}

.tab-btn {
    padding: 0.75rem 1.5rem;
    background: transparent;
    border: none;
    border-bottom: 3px solid transparent;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: all 0.2s;
    margin-bottom: -2px;
}

.tab-btn:hover {
    color: var(--text-primary);
}

.tab-btn.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.3s;
}

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

/* Editor Container */
.editor-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.editor-section {
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
    overflow: hidden;
}

.editor-header {
    padding: 1rem;
    background: linear-gradient(to right, #f8f9fa, #ffffff);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.editor-header h3 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.actions {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.json-editor {
    width: 100%;
    min-height: 400px;
    padding: 1rem;
    border: none;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 14px;
    line-height: 1.5;
    resize: vertical;
    background: var(--card-bg);
    color: var(--text-primary);
}

.json-editor:focus {
    outline: none;
    background: #fafbfc;
}

.json-editor[readonly] {
    background: #f8f9fa;
    color: var(--text-secondary);
}

/* Buttons */
.btn {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

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

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

.btn-success {
    background: var(--success-color);
    color: white;
}

.btn-success:hover {
    background: #00a038;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: #e4e6ea;
    color: var(--text-primary);
}

.btn-secondary:hover {
    background: #d3d6db;
}

.action-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin: 2rem 0;
}

/* Messages */
.error-message {
    padding: 0.75rem 1rem;
    margin: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    display: none;
}

.error-message:not(:empty) {
    display: block;
}

.error-message.error {
    background: #ffe4e4;
    color: var(--error-color);
    border-left: 4px solid var(--error-color);
}

.error-message.success {
    background: #e6f7ed;
    color: var(--success-color);
    border-left: 4px solid var(--success-color);
}

/* Stats */
.stats, .compression-stats {
    padding: 0.75rem 1rem;
    background: #f8f9fa;
    border-top: 1px solid var(--border-color);
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.compression-stats {
    display: flex;
    justify-content: space-around;
}

.compression-stats .saved {
    color: var(--success-color);
    font-weight: 600;
}

/* Compare Result */
.compare-result {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 1.5rem;
    margin-top: 2rem;
    box-shadow: var(--shadow-md);
    display: none;
}

.compare-result:not(:empty) {
    display: block;
}

.compare-success {
    color: var(--success-color);
    font-size: 1.125rem;
    font-weight: 500;
    text-align: center;
}

.compare-error {
    color: var(--error-color);
    font-size: 1.125rem;
    font-weight: 500;
    margin-bottom: 1rem;
}

.diff-list {
    margin-top: 1rem;
}

.diff-item {
    padding: 0.75rem;
    margin: 0.5rem 0;
    border-radius: var(--radius-sm);
    font-family: monospace;
    font-size: 0.875rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.diff-added {
    background: #e6f7ed;
    border-left: 3px solid var(--success-color);
}

.diff-removed {
    background: #ffe4e4;
    border-left: 3px solid var(--error-color);
}

.diff-changed {
    background: #fff4e5;
    border-left: 3px solid var(--warning-color);
}

.diff-type {
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.75rem;
}

.diff-path {
    flex: 1;
    color: var(--text-primary);
}

.diff-old {
    color: var(--error-color);
    text-decoration: line-through;
}

.diff-new {
    color: var(--success-color);
}

/* Select */
.indent-select {
    padding: 0.375rem 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: white;
    font-size: 0.875rem;
    cursor: pointer;
}

/* Features Section */
.features {
    margin-top: 4rem;
    padding: 3rem 0;
    background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
    border-radius: var(--radius);
}

.features h2 {
    text-align: center;
    margin-bottom: 2rem;
    font-size: 1.75rem;
    color: var(--text-primary);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.feature-card {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    transition: all 0.3s;
    text-align: center;
}

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

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.5;
}

/* Footer */
footer {
    background: var(--text-primary);
    color: white;
    padding: 1.5rem 0;
    margin-top: 4rem;
}

footer p {
    text-align: center;
    font-size: 0.875rem;
    opacity: 0.8;
}

/* Toast */
.toast {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: var(--text-primary);
    color: white;
    padding: 1rem 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    z-index: 1000;
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.3s;
}

.toast.show {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive */
@media (max-width: 768px) {
    .editor-container {
        grid-template-columns: 1fr;
    }
    
    .json-editor {
        min-height: 300px;
    }
    
    .tabs {
        overflow-x: auto;
        white-space: nowrap;
    }
    
    .feature-grid {
        grid-template-columns: 1fr;
    }
    
    header .container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .action-buttons {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
}

/* Loading Animation */
@keyframes pulse {
    0% { opacity: 1; }
    50% { opacity: 0.5; }
    100% { opacity: 1; }
}

.loading {
    animation: pulse 1.5s infinite;
}

/* Scrollbar Styling */
.json-editor::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

.json-editor::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 4px;
}

.json-editor::-webkit-scrollbar-thumb {
    background: #c1c1c1;
    border-radius: 4px;
}

.json-editor::-webkit-scrollbar-thumb:hover {
    background: #a8a8a8;
}