:root {
    --bg-main: #0C1222;
    --bg-surface: #1A2133;
    --bg-surface-hover: #242D45;
    --text-primary: #F8FAFC;
    --text-secondary: #94A3B8;
    --text-muted: #64748B;
    
    --primary: #0EA5E9;
    --primary-hover: #0284C7;
    --danger: #EF4444;
    --danger-hover: #DC2626;
    --warning: #F59E0B;
    --success: #10B981;
    
    --border-color: #334155;
    --border-radius: 8px;
    --radius-sm: 4px;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    
    --node-colors: #0EA5E9, #8B5CF6, #EC4899, #10B981, #F59E0B, #6366F1, #14B8A6, #F43F5E;
}

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

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-main);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

.app-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

/* Header */
.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1.5rem;
}

h1 {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.025em;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

.slo-target-card {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    background-color: var(--bg-surface);
    padding: 1rem;
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
}

.slo-target-card label {
    font-size: 0.75rem;
    text-transform: uppercase;
    font-weight: 600;
    color: var(--text-secondary);
    letter-spacing: 0.05em;
}

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

input[type="number"], input[type="text"], select {
    background-color: var(--bg-main);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.5rem;
    border-radius: var(--radius-sm);
    font-family: inherit;
    font-size: 0.875rem;
}

input[type="number"] {
    width: 80px;
}

input:focus, select:focus {
    outline: none;
    border-color: var(--primary);
}

.unit {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Toolbar */
.toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.toolbar-group {
    display: flex;
    gap: 0.75rem;
    align-items: center;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    border: 1px solid transparent;
}

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

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

.btn-outline {
    background-color: transparent;
    border-color: var(--border-color);
    color: var(--text-primary);
}

.btn-outline:hover {
    background-color: var(--bg-surface);
    border-color: var(--text-secondary);
}

.btn-danger-outline {
    background-color: transparent;
    border-color: var(--border-color);
    color: var(--danger);
}

.btn-danger-outline:hover {
    background-color: rgba(239, 68, 68, 0.1);
    border-color: var(--danger);
}

.btn-icon {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.25rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
    transition: color 0.2s, background-color 0.2s;
}

.btn-icon:hover {
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
}

.btn-remove-node:hover {
    color: var(--danger);
    background-color: rgba(239, 68, 68, 0.1);
}

/* Overview Section */
.budget-overview-section {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
}

.overview-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

h2 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
}

.budget-stats {
    display: flex;
    gap: 1.5rem;
    font-size: 0.875rem;
}

.stat-item {
    color: var(--text-secondary);
}

.stat-item strong {
    color: var(--text-primary);
    margin-left: 0.25rem;
}

strong.success { color: var(--success); }
strong.warning { color: var(--warning); }
strong.danger { color: var(--danger); }

.stacked-bar-container {
    width: 100%;
}

.stacked-bar {
    height: 24px;
    background-color: var(--bg-main);
    border-radius: 12px;
    display: flex;
    overflow: hidden;
    margin-bottom: 0.5rem;
    border: 1px solid var(--border-color);
}

.bar-segment {
    height: 100%;
    transition: width 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    color: white;
    font-weight: 600;
    text-shadow: 0 1px 2px rgba(0,0,0,0.5);
    overflow: hidden;
    white-space: nowrap;
}

.bar-segment.over-budget {
    background-image: repeating-linear-gradient(
        45deg,
        rgba(255, 255, 255, 0.1),
        rgba(255, 255, 255, 0.1) 10px,
        transparent 10px,
        transparent 20px
    );
}

.bar-labels {
    display: flex;
    justify-content: space-between;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* Path Builder */
.path-builder-section {
    padding: 1rem 0;
}

.path-visualizer {
    display: flex;
    align-items: center;
    gap: 0;
    padding: 2rem 0;
    overflow-x: auto;
    position: relative;
    min-height: 120px;
}

.path-node {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
    position: relative;
    z-index: 2;
}

.path-node-icon {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: white;
    box-shadow: 0 0 0 4px var(--bg-main), 0 0 0 6px var(--border-color);
    background-color: var(--bg-surface);
}

.path-node-label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
    white-space: nowrap;
}

.path-connector {
    flex-grow: 1;
    min-width: 40px;
    height: 2px;
    background-color: var(--border-color);
    position: relative;
    z-index: 1;
}

.path-connector::after {
    content: '';
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    border-width: 4px;
    border-style: solid;
    border-color: transparent transparent transparent var(--border-color);
}

/* Two Column Layout */
.two-column-layout {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 1.5rem;
}

@media (max-width: 900px) {
    .two-column-layout {
        grid-template-columns: 1fr;
    }
}

/* Node List */
.nodes-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-top: 1rem;
}

.node-card {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1.25rem;
}

.node-card.over-budget {
    border-color: var(--danger);
    box-shadow: 0 0 0 1px var(--danger);
}

.node-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.node-title-group {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.node-color-indicator {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.node-name-input {
    font-size: 1rem;
    font-weight: 600;
    background: transparent;
    border: 1px solid transparent;
    padding: 0.25rem 0.5rem;
    width: 200px;
}

.node-name-input:hover, .node-name-input:focus {
    background-color: var(--bg-main);
    border-color: var(--border-color);
}

.latency-inputs {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.input-group label {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.input-group input {
    width: 100%;
}

.slider-group {
    margin-bottom: 1rem;
}

.slider-group label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    display: block;
    margin-bottom: 0.5rem;
}

.slider-container {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.latency-slider {
    -webkit-appearance: none;
    flex-grow: 1;
    height: 6px;
    background: var(--bg-main);
    border-radius: 3px;
    outline: none;
}

.latency-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--text-primary);
    cursor: pointer;
    transition: transform 0.1s;
}

.latency-slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

.slider-value {
    font-size: 0.875rem;
    font-weight: 600;
    font-variant-numeric: tabular-nums;
    width: 60px;
    text-align: right;
}

.distribution-preview {
    margin-top: 1rem;
    border-top: 1px solid var(--border-color);
    padding-top: 1rem;
}

.bell-curve-canvas {
    width: 100%;
    height: 60px;
}

/* Suggestions Panel */
.suggestions-panel {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
}

.suggestions-list {
    list-style: none;
    margin-top: 1rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.suggestions-list li {
    padding: 1rem;
    background-color: var(--bg-main);
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--primary);
    font-size: 0.875rem;
}

.suggestions-list li.suggestion-danger {
    border-left-color: var(--danger);
}

.suggestions-list li.suggestion-warning {
    border-left-color: var(--warning);
}

.suggestion-empty {
    color: var(--text-muted);
    border-left-color: var(--border-color) !important;
}

/* Printable Report Styles */
@media print {
    body {
        background-color: white;
        color: black;
    }
    .app-header, .toolbar, .node-card, .suggestions-panel {
        background-color: transparent;
        border-color: #ccc;
    }
    .stacked-bar-container, .bell-curve-canvas {
        -webkit-print-color-adjust: exact;
        print-color-adjust: exact;
    }
    .btn, input[type="range"] {
        display: none;
    }
    input[type="number"], input[type="text"], select {
        border: none;
        background: transparent;
        color: black;
    }
}