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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'SF Pro Text', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    background: #f5f5f7;
    min-height: 100vh;
    padding: 40px 20px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: #ffffff;
    border-radius: 18px;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
    padding: 48px;
}

header {
    text-align: center;
    margin-bottom: 40px;
}

header h1 {
    color: #1d1d1f;
    font-size: 48px;
    font-weight: 700;
    letter-spacing: -0.003em;
    line-height: 1.08;
    margin-bottom: 8px;
}

header p {
    color: #86868b;
    font-size: 19px;
    font-weight: 400;
    line-height: 1.42;
}

.input-section {
    display: flex;
    gap: 12px;
    margin-bottom: 24px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

#urlInput {
    flex: 1;
    padding: 14px 18px;
    border: 1px solid #d2d2d7;
    border-radius: 12px;
    font-size: 15px;
    background: #fafafa;
    transition: all 0.2s ease;
    color: #1d1d1f;
}

#urlInput:focus {
    outline: none;
    border-color: #0071e3;
    background: #ffffff;
    box-shadow: 0 0 0 4px rgba(0, 113, 227, 0.15);
}

#urlInput::placeholder {
    color: #86868b;
}

#fetchBtn {
    padding: 14px 26px;
    background: #0071e3;
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

#fetchBtn:hover {
    background: #0077ed;
}

#fetchBtn:active {
    background: #0065c0;
    transform: scale(0.98);
}

.controls {
    display: flex;
    gap: 24px;
    margin-bottom: 24px;
    justify-content: center;
    flex-wrap: wrap;
}

.controls label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    color: #1d1d1f;
    font-size: 14px;
    font-weight: 400;
    user-select: none;
}

.controls input[type="checkbox"] {
    width: 16px;
    height: 16px;
    cursor: pointer;
    accent-color: #0071e3;
}

#status {
    padding: 14px 18px;
    border-radius: 12px;
    margin-bottom: 24px;
    font-size: 15px;
    text-align: center;
    display: none;
}

#status.error {
    background: #fff2f2;
    color: #d32f2f;
    border: 1px solid #ffcdd2;
    display: block;
}

#status.loading {
    background: #f0f8ff;
    color: #0071e3;
    border: 1px solid #b3d9ff;
    display: block;
}

.content-wrapper {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 24px;
    min-height: 400px;
    align-items: start;
}

.tree-panel {
    background: #fafafa;
    border-radius: 14px;
    padding: 24px;
    overflow: auto;
    max-height: 600px;
}

.stats-panel, .bs4-panel {
    background: #fafafa;
    border-radius: 14px;
    padding: 24px;
}

.stats-panel {
    overflow: auto;
    max-height: 280px;
}

.bs4-panel {
    overflow: auto;
    max-height: 280px;
}

.tree-panel h2, .stats-panel h2, .bs4-panel h2 {
    color: #1d1d1f;
    margin-bottom: 16px;
    font-size: 20px;
    font-weight: 600;
    position: sticky;
    top: 0;
    background: #fafafa;
    padding-bottom: 12px;
    letter-spacing: -0.01em;
    z-index: 1;
}

.tree-panel h2 {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.hint {
    font-size: 13px;
    font-weight: 400;
    color: #86868b;
}

.right-panel {
    display: flex;
    flex-direction: column;
    gap: 24px;
    min-width: 0;
}

.bs4-panel {
    background: #fafafa;
    border-radius: 14px;
    padding: 24px;
}

.bs4-controls {
    margin-bottom: 12px;
    display: flex;
    gap: 8px;
}

#copyBtn {
    padding: 8px 16px;
    background: #0071e3;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

#copyBtn:hover {
    background: #0077ed;
}

#copyBtn:active {
    background: #0065c0;
    transform: scale(0.98);
}

#bs4Code {
    background: #1d1d1f;
    color: #f5f5f7;
    padding: 16px;
    border-radius: 10px;
    overflow-x: auto;
    font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;
    font-size: 12px;
    line-height: 1.6;
    margin: 0;
    max-height: 300px;
    overflow-y: auto;
}

#bs4Code code {
    color: #f5f5f7;
}

.node-header.selected {
    background: #0071e3;
}

.node-header.selected .node-tag,
.node-header.selected .node-attrs,
.node-header.selected .node-text {
    color: white;
}

.node-header.selected .node-toggle {
    color: rgba(255, 255, 255, 0.8);
}

.tree-node {
    margin-left: 18px;
    border-left: 1px solid #e5e5e7;
    padding-left: 12px;
    margin-top: 2px;
}

.tree-node-root {
    margin-left: 0;
    border-left: none;
    padding-left: 0;
}

.node-header {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 10px;
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.15s ease;
}

.node-header:hover {
    background: #e8e8ed;
}

.node-toggle {
    width: 14px;
    height: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 10px;
    color: #86868b;
    cursor: pointer;
    user-select: none;
    transition: transform 0.15s ease;
}

.node-tag {
    color: #0071e3;
    font-weight: 500;
    font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;
    font-size: 13px;
}

.node-attrs {
    color: #86868b;
    font-size: 12px;
    font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;
}

.node-text {
    color: #30d158;
    font-size: 12px;
    font-style: normal;
}

.node-children {
    display: none;
}

.node-children.expanded {
    display: block;
}

.stat-item {
    display: flex;
    justify-content: space-between;
    padding: 12px 0;
    border-bottom: 1px solid #e5e5e7;
}

.stat-item:last-child {
    border-bottom: none;
}

.stat-label {
    color: #86868b;
    font-size: 14px;
    font-weight: 400;
}

.stat-value {
    font-weight: 600;
    color: #1d1d1f;
    font-size: 15px;
}

#tagChart {
    margin-top: 20px;
}

#tagChart h3 {
    margin-bottom: 14px;
    font-size: 15px;
    color: #1d1d1f;
    font-weight: 600;
}

.bar-item {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
}

.bar-label {
    width: 70px;
    font-size: 12px;
    color: #1d1d1f;
    font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;
    font-weight: 500;
}

.bar-wrapper {
    flex: 1;
    height: 20px;
    background: #e5e5e7;
    border-radius: 6px;
    overflow: hidden;
}

.bar-fill {
    height: 100%;
    background: linear-gradient(90deg, #0071e3 0%, #0055b3 100%);
    transition: width 0.4s ease;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding-right: 8px;
}

.bar-value {
    color: white;
    font-size: 11px;
    font-weight: 600;
}

@media (max-width: 900px) {
    .container {
        padding: 32px 24px;
    }

    header h1 {
        font-size: 36px;
    }

    .content-wrapper {
        grid-template-columns: 1fr;
    }

    .tree-panel, .stats-panel {
        max-height: 400px;
    }
}