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

:root {
    --color-canvas-default: #ffffff;
    --color-canvas-subtle: #f6f8fa;
    --color-border-default: #d0d7de;
    --color-border-muted: #d8dee4;
    --color-neutral-muted: rgba(175,184,193,0.2);
    --color-accent-fg: #0969da;
    --color-accent-emphasis: #0969da;
    --color-danger-fg: #cf222e;
    --color-success-fg: #1a7f37;
    --color-done-fg: #8250df;
    --color-primer-shadow-focus: 0 0 0 3px rgba(9,105,218,0.3);
    --color-fg-default: #24292f;
    --color-fg-muted: #57606a;
    --color-fg-subtle: #6e7781;
}

body {
    font-family: -apple-system,BlinkMacSystemFont,"Segoe UI","Noto Sans",Helvetica,Arial,sans-serif,"Apple Color Emoji","Segoe UI Emoji";
    background: var(--color-canvas-subtle);
    min-height: 100vh;
    padding: 20px;
    color: var(--color-fg-default);
    line-height: 1.5;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    background: var(--color-canvas-default);
    border-radius: 6px;
    box-shadow: 0 1px 0 rgba(27,31,36,0.04);
    border: 1px solid var(--color-border-default);
}

.header {
    padding: 16px;
    background: var(--color-canvas-subtle);
    border-bottom: 1px solid var(--color-border-muted);
    border-top-left-radius: 6px;
    border-top-right-radius: 6px;
}

.header h1 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 4px;
    color: var(--color-fg-default);
}

.header p {
    font-size: 14px;
    color: var(--color-fg-muted);
    margin: 0;
}

.main-content {
    padding: 24px;
}

.input-section {
    margin-bottom: 16px;
}

.section-title {
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--color-fg-muted);
    border: none;
    padding: 0;
    display: block;
}

.textarea-container {
    position: relative;
    margin-bottom: 20px;
}

textarea {
    width: 100%;
    min-height: 240px;
    padding: 16px;
    border: 1px solid var(--color-border-default);
    border-radius: 6px;
    font-family: ui-monospace,SFMono-Regular,SF Mono,Menlo,Consolas,Liberation Mono,monospace;
    font-size: 13px;
    line-height: 1.5;
    resize: vertical;
    background: var(--color-canvas-subtle);
    color: var(--color-fg-default);
}

textarea:focus {
    outline: none;
    border-color: var(--color-accent-emphasis);
    box-shadow: var(--color-primer-shadow-focus);
}

textarea::placeholder {
    color: var(--color-fg-subtle);
}

button {
    padding: 5px 16px;
    border: 1px solid var(--color-border-default);
    border-radius: 6px;
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    background: var(--color-canvas-default);
    color: var(--color-fg-default);
    transition: 0.2s cubic-bezier(0.3, 0, 0.5, 1);
    white-space: nowrap;
}

button:hover {
    background: var(--color-canvas-subtle);
}

.copy-btn {
    color: var(--color-accent-fg);
    border-color: var(--color-accent-fg);
    background: transparent;
}

.copy-btn:hover {
    color: #ffffff;
    background: var(--color-accent-fg);
}

.output-section {
    margin-top: 16px;
}

.output-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
}

.output-actions {
    display: flex;
    gap: 8px;
}

.output-actions button {
    padding: 4px 12px;
    font-size: 12px;
}

.output-area {
    background: var(--color-canvas-subtle);
    color: var(--color-fg-default);
    padding: 16px;
    border-radius: 6px;
    font-family: ui-monospace,SFMono-Regular,SF Mono,Menlo,Consolas,Liberation Mono,monospace;
    font-size: 13px;
    line-height: 1.5;
    white-space: pre-wrap;
    word-wrap: break-word;
    min-height: 240px;
    max-height: 600px;
    overflow-y: auto;
    border: 1px solid var(--color-border-default);
}

.message-container {
    margin: 16px 0;
    min-height: 40px;
}

.message-container {
    margin: 16px 0;
    min-height: 40px;
}

.error, .success {
    padding: 8px 16px;
    border-radius: 6px;
    display: none;
    opacity: 0;
    transform: translateY(-4px);
    transition: all 0.2s ease-out;
    margin-bottom: 8px;
    font-family: ui-monospace,SFMono-Regular,SF Mono,Menlo,Consolas,Liberation Mono,monospace;
    white-space: pre-wrap;
    line-height: 1.5;
}

.error {
    border: 1px solid rgba(207,34,46,0.3);
    background: #FFEBE9;
    color: var(--color-danger-fg);
}

.success {
    border: 1px solid rgba(26,127,55,0.3);
    background: #dafbe1;
    color: var(--color-success-fg);
}

.error[style*="display: block"],
.success[style*="display: block"] {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    animation: slideIn 0.3s ease-out;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

@keyframes slideIn {
    from { transform: translateY(-20px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.json-key { color: #24292f; }
.json-string { color: #0A3069; }
.json-number { color: #0550AE; }
.json-boolean { color: #CF222E; }
.json-null { color: #CF222E; }





.button-group {
    display: flex;
    gap: 8px;
    margin-bottom: 16px;
}

.format-btn {
    color: var(--color-accent-fg);
    border-color: var(--color-accent-fg);
    background: transparent;
}

.format-btn:hover {
    color: #ffffff;
    background: var(--color-accent-fg);
}

.minify-btn {
    color: var(--color-accent-fg);
    border-color: var(--color-accent-fg);
    background: transparent;
}

.minify-btn:hover {
    color: #ffffff;
    background: var(--color-accent-fg);
}



@media (max-width: 768px) {
    .main-content {
        padding: 20px;
    }
    
    .header h1 {
        font-size: 2rem;
    }
    
    .button-group {
        flex-direction: column;
    }
    
    button {
        width: 100%;
    }
}