/* ===== Design Tokens (reused from observability-cost-calculator) ===== */
:root {
    --color-background: #ffffff;
    --color-text: #111111;
    --color-text-secondary: #666666;
    --color-accent: #10b981;
    --color-accent-light: #10b98110;
    --color-border: #e5e5e5;
    --color-error: #ef4444;
    --color-success: #10b981;
    --color-surface: #fafafa;
    --spacing-unit: 4px;
    --border-radius: 8px;
    --font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-size-base: 16px;
    --font-size-small: 14px;
    --font-size-large: 20px;
    --font-weight-normal: 400;
    --font-weight-bold: 700;
    --max-width: 1200px;
}

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

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-normal);
    color: var(--color-text);
    background-color: var(--color-background);
    line-height: 1.5;
}

.app {
    min-height: 100vh;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 calc(var(--spacing-unit) * 6);
}

/* ===== Skip link & focus ===== */
.skip-link {
    position: absolute;
    left: -9999px;
    top: 0;
    background: var(--color-accent);
    color: #fff;
    padding: calc(var(--spacing-unit) * 3) calc(var(--spacing-unit) * 4);
    border-radius: var(--border-radius);
    z-index: 1000;
}
.skip-link:focus {
    left: var(--spacing-unit) * 4;
    top: var(--spacing-unit) * 4;
}

:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

.section-header {
    font-size: var(--font-size-large);
    font-weight: var(--font-weight-bold);
    margin-bottom: calc(var(--spacing-unit) * 4);
    padding-bottom: var(--spacing-unit);
    border-bottom: 1px solid var(--color-border);
}

.subsection-header {
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-bold);
    margin-bottom: calc(var(--spacing-unit) * 3);
}

/* ===== Topbar ===== */
.topbar {
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: calc(var(--spacing-unit) * 3) calc(var(--spacing-unit) * 6);
    background-color: rgba(255, 255, 255, 0.92);
    border-bottom: 1px solid var(--color-border);
    backdrop-filter: blur(6px);
}
.brand {
    font-weight: var(--font-weight-bold);
    font-size: var(--font-size-small);
}
.topbar-cta {
    font-size: var(--font-size-small);
    font-weight: var(--font-weight-bold);
    color: #fff;
    background-color: var(--color-accent);
    text-decoration: none;
    padding: calc(var(--spacing-unit) * 2) calc(var(--spacing-unit) * 3);
    border-radius: var(--border-radius);
}
.topbar-cta:hover {
    background-color: #059669;
}

/* ===== Hero ===== */
.hero {
    padding: calc(var(--spacing-unit) * 16) 0 calc(var(--spacing-unit) * 12);
    text-align: center;
    background-color: var(--color-background);
}
.hero-content {
    max-width: 820px;
    margin: 0 auto;
    padding: 0 calc(var(--spacing-unit) * 4);
}
.hero-eyebrow {
    font-size: var(--font-size-small);
    color: var(--color-accent);
    font-weight: var(--font-weight-bold);
    letter-spacing: 0.04em;
    margin-bottom: calc(var(--spacing-unit) * 3);
    text-transform: uppercase;
}
.hero-title {
    font-size: 48px;
    font-weight: var(--font-weight-bold);
    line-height: 1.2;
    margin-bottom: calc(var(--spacing-unit) * 4);
}
.hero-subtitle {
    font-size: var(--font-size-large);
    color: var(--color-text-secondary);
    margin-bottom: calc(var(--spacing-unit) * 6);
    max-width: 640px;
    margin-left: auto;
    margin-right: auto;
}
.hero-stat {
    margin-bottom: calc(var(--spacing-unit) * 8);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: calc(var(--spacing-unit) * 1);
}
.hero-stat-number {
    font-size: 96px;
    font-weight: var(--font-weight-bold);
    line-height: 1;
    color: var(--color-text);
    font-variant-numeric: tabular-nums;
    letter-spacing: -0.03em;
}
.hero-stat-x {
    color: var(--color-accent);
}
.hero-stat-label {
    font-size: var(--font-size-base);
    color: var(--color-text-secondary);
    font-weight: var(--font-weight-bold);
}

/* ===== CTA Button ===== */
.cta-button {
    display: inline-block;
    padding: calc(var(--spacing-unit) * 3) calc(var(--spacing-unit) * 8);
    min-height: 48px;
    line-height: 24px;
    background-color: var(--color-accent);
    color: #ffffff;
    font-weight: var(--font-weight-bold);
    font-size: var(--font-size-base);
    text-decoration: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: background-color 0.2s;
    border: none;
}
.cta-button:hover {
    background-color: #059669;
}

/* ===== Calculator ===== */
.calculator {
    padding: calc(var(--spacing-unit) * 12) 0;
    background-color: var(--color-surface);
}
.calculator-container {
    display: flex;
    gap: calc(var(--spacing-unit) * 8);
    align-items: flex-start;
}
.input-panel, .result-panel {
    flex: 1;
    background-color: var(--color-background);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: calc(var(--spacing-unit) * 8);
}
.input-panel {
    border-top: 3px solid var(--color-accent);
}

fieldset {
    border: none;
}
.input-group {
    margin-bottom: calc(var(--spacing-unit) * 6);
}
.input-label {
    display: block;
    font-weight: var(--font-weight-bold);
    margin-bottom: calc(var(--spacing-unit) * 2);
    padding: 0;
    font-size: var(--font-size-base);
}
.input-hint {
    font-size: var(--font-size-small);
    color: var(--color-text-secondary);
    margin-top: calc(var(--spacing-unit) * 2);
}

.slider-container {
    display: flex;
    align-items: center;
    gap: calc(var(--spacing-unit) * 3);
}
.slider {
    flex: 1;
    height: 4px;
    border-radius: 2px;
    background: var(--color-border);
    -webkit-appearance: none;
    appearance: none;
    cursor: pointer;
}
.slider:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 4px;
}
.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--color-accent);
    cursor: pointer;
    border: 2px solid #fff;
    box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}
.slider::-moz-range-thumb {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--color-accent);
    cursor: pointer;
    border: 2px solid #fff;
}
.slider-value {
    min-width: 56px;
    text-align: right;
    font-weight: var(--font-weight-bold);
    font-variant-numeric: tabular-nums;
}

.radio-group, .checkbox-group {
    display: flex;
    gap: calc(var(--spacing-unit) * 4);
    margin-top: calc(var(--spacing-unit) * 1);
}
.radio, .checkbox {
    display: flex;
    align-items: center;
    gap: calc(var(--spacing-unit) * 2);
    font-size: var(--font-size-base);
}
.radio input, .checkbox input {
    width: 24px;
    height: 24px;
    margin: 0;
    cursor: pointer;
    accent-color: var(--color-accent);
}

.input-error {
    color: var(--color-error);
    font-size: var(--font-size-small);
    padding: calc(var(--spacing-unit) * 2) 0;
    font-weight: var(--font-weight-bold);
}

.calculate-button {
    width: 100%;
    padding: calc(var(--spacing-unit) * 4) calc(var(--spacing-unit) * 4);
    min-height: 52px;
    background-color: var(--color-accent);
    color: #fff;
    border: none;
    border-radius: var(--border-radius);
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-bold);
    cursor: pointer;
    transition: background-color 0.2s;
}
.calculate-button:hover {
    background-color: #059669;
}
.calculate-button[aria-busy="true"] {
    opacity: 0.7;
    pointer-events: none;
}

/* ===== Result Panel ===== */
.empty-state {
    color: var(--color-text-secondary);
    padding: calc(var(--spacing-unit) * 12) calc(var(--spacing-unit) * 4);
    text-align: left;
    background-color: var(--color-surface);
    border: 1px dashed var(--color-border);
    border-radius: var(--border-radius);
    font-size: var(--font-size-base);
}
.result-summary {
    animation: fadeIn 0.3s ease;
}
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.result-cards {
    display: flex;
    gap: calc(var(--spacing-unit) * 3);
    margin-bottom: calc(var(--spacing-unit) * 5);
}
.result-card {
    flex: 1;
    padding: calc(var(--spacing-unit) * 5);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    text-align: left;
}
.result-card.savings {
    background-color: var(--color-accent-light);
    border-color: var(--color-accent);
}
.result-card h3 {
    font-size: var(--font-size-small);
    margin-bottom: calc(var(--spacing-unit) * 2);
    color: var(--color-text-secondary);
    font-weight: var(--font-weight-bold);
}
.result-value {
    font-size: 32px;
    font-weight: var(--font-weight-bold);
    margin-bottom: calc(var(--spacing-unit) * 1);
    font-variant-numeric: tabular-nums;
    line-height: 1.1;
}
.result-label {
    font-size: var(--font-size-small);
    color: var(--color-text-secondary);
    margin-bottom: calc(var(--spacing-unit) * 2);
}
.result-sub {
    font-size: var(--font-size-small);
    color: var(--color-text-secondary);
}
.result-card.savings .result-value {
    color: var(--color-success);
}
.result-card.savings.no-savings {
    background-color: #fff7f7;
    border-color: var(--color-error);
}
.result-card.savings.no-savings .result-value {
    color: var(--color-text-secondary);
}
.result-card.savings.no-savings .result-label {
    color: var(--color-error);
    font-weight: var(--font-weight-bold);
}

/* Payback badge */
.payback-badge {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: calc(var(--spacing-unit) * 3);
    background-color: var(--color-accent-light);
    border: 1px solid var(--color-accent);
    color: var(--color-accent);
    border-radius: var(--border-radius);
    padding: calc(var(--spacing-unit) * 4) calc(var(--spacing-unit) * 5);
    margin-bottom: calc(var(--spacing-unit) * 6);
}
.payback-label {
    font-size: var(--font-size-small);
    font-weight: var(--font-weight-bold);
}
.payback-value {
    font-size: var(--font-size-large);
    font-weight: var(--font-weight-bold);
    font-variant-numeric: tabular-nums;
}

/* Chart */
.chart-container {
    margin-bottom: calc(var(--spacing-unit) * 6);
}
.chart-empty {
    color: var(--color-text-secondary);
    padding: calc(var(--spacing-unit) * 8) 0;
    text-align: left;
    font-size: var(--font-size-small);
}
.chart-wrap {
    width: 100%;
    height: 300px;
}
.chart-wrap svg {
    width: 100%;
    height: 100%;
    display: block;
}
.chart-legend {
    display: flex;
    gap: calc(var(--spacing-unit) * 6);
    margin-top: calc(var(--spacing-unit) * 3);
    font-size: var(--font-size-small);
}
.legend-item {
    display: flex;
    align-items: center;
    gap: calc(var(--spacing-unit) * 2);
}
.legend-line {
    display: inline-block;
    width: 28px;
    height: 0;
    border-top: 3px solid var(--color-error);
}
.legend-line-oss {
    border-top: 3px dashed var(--color-success);
}

/* Comparison table */
.comparison-table {
    margin-bottom: calc(var(--spacing-unit) * 2);
}
.table-scroll {
    overflow-x: auto;
}
.comparison-table table {
    width: 100%;
    border-collapse: collapse;
    font-variant-numeric: tabular-nums;
}
.comparison-table th, .comparison-table td {
    padding: calc(var(--spacing-unit) * 3) calc(var(--spacing-unit) * 4);
    text-align: left;
    border-bottom: 1px solid var(--color-border);
    white-space: nowrap;
}
.comparison-table th {
    font-weight: var(--font-weight-bold);
    background-color: var(--color-surface);
    font-size: var(--font-size-small);
}
.comparison-table td {
    font-size: var(--font-size-small);
}
.comparison-table td.num {
    text-align: right;
}
.comparison-table tr.total {
    font-weight: var(--font-weight-bold);
}
.comparison-table tr.total td {
    border-top: 2px solid var(--color-border);
    border-bottom: none;
}

/* ===== Roadmap ===== */
.roadmap {
    padding: calc(var(--spacing-unit) * 12) 0;
    background-color: var(--color-background);
}
.roadmap-intro {
    color: var(--color-text-secondary);
    margin-bottom: calc(var(--spacing-unit) * 6);
    max-width: 720px;
}
.timeline {
    list-style: none;
    padding: 0;
    position: relative;
}
.timeline::before {
    content: "";
    position: absolute;
    left: 7px;
    top: 8px;
    bottom: 8px;
    width: 2px;
    background-color: var(--color-border);
}
.timeline-item {
    position: relative;
    padding-left: calc(var(--spacing-unit) * 9);
    padding-bottom: calc(var(--spacing-unit) * 7);
}
.timeline-item:last-child {
    padding-bottom: 0;
}
.timeline-dot {
    position: absolute;
    left: 0;
    top: 6px;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background-color: var(--color-accent);
    border: 3px solid var(--color-background);
    box-shadow: 0 0 0 2px var(--color-accent);
}
.timeline-date {
    display: inline-block;
    font-size: var(--font-size-small);
    color: var(--color-accent);
    font-weight: var(--font-weight-bold);
    margin-bottom: calc(var(--spacing-unit) * 1);
}
.timeline-title {
    font-size: var(--font-size-large);
    font-weight: var(--font-weight-bold);
    margin-bottom: calc(var(--spacing-unit) * 2);
}
.timeline-desc {
    color: var(--color-text-secondary);
    max-width: 680px;
}

/* ===== Methodology ===== */
.methodology {
    padding: calc(var(--spacing-unit) * 12) 0;
    background-color: var(--color-surface);
}
.methodology-content {
    max-width: 820px;
}
.methodology-content > p {
    margin-bottom: calc(var(--spacing-unit) * 4);
    color: var(--color-text-secondary);
}
.pricing-block {
    background-color: var(--color-background);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: calc(var(--spacing-unit) * 6);
    margin: calc(var(--spacing-unit) * 4) 0 calc(var(--spacing-unit) * 6);
}
.pricing-block .pricing-row {
    display: flex;
    justify-content: space-between;
    gap: calc(var(--spacing-unit) * 4);
    padding: calc(var(--spacing-unit) * 2) 0;
    border-bottom: 1px solid var(--color-border);
    font-size: var(--font-size-small);
}
.pricing-block .pricing-row:last-child {
    border-bottom: none;
}
.pricing-block .pricing-row .price {
    font-weight: var(--font-weight-bold);
    font-variant-numeric: tabular-nums;
}
.pricing-group-title {
    font-weight: var(--font-weight-bold);
    margin-top: calc(var(--spacing-unit) * 4);
    margin-bottom: calc(var(--spacing-unit) * 1);
    font-size: var(--font-size-small);
    color: var(--color-text);
}
.pricing-group-title:first-child {
    margin-top: 0;
}
.assumptions-list {
    margin: calc(var(--spacing-unit) * 2) 0 calc(var(--spacing-unit) * 5);
    padding-left: calc(var(--spacing-unit) * 6);
    color: var(--color-text-secondary);
    font-size: var(--font-size-small);
}
.assumptions-list li {
    margin-bottom: calc(var(--spacing-unit) * 2);
}
.rate-note {
    font-size: var(--font-size-small);
    color: var(--color-text-secondary);
    padding-top: calc(var(--spacing-unit) * 3);
    border-top: 1px solid var(--color-border);
}

/* ===== Email gate ===== */
.email-gate {
    padding: calc(var(--spacing-unit) * 12) 0;
    background-color: var(--color-background);
}
.email-gate-body {
    max-width: 560px;
}
.email-gate-body > p {
    color: var(--color-text-secondary);
    margin-bottom: calc(var(--spacing-unit) * 5);
}
.email-form {
    display: flex;
    flex-direction: column;
    gap: calc(var(--spacing-unit) * 3);
}
.email-field {
    display: flex;
    flex-direction: column;
    gap: calc(var(--spacing-unit) * 2);
}
.email-field input[type="email"] {
    width: 100%;
    padding: calc(var(--spacing-unit) * 3) calc(var(--spacing-unit) * 4);
    min-height: 48px;
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    font-size: var(--font-size-base);
    font-family: var(--font-family);
}
.email-field input[type="email"]:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
    border-color: var(--color-accent);
}
.email-field input[type="email"].invalid {
    border-color: var(--color-error);
}
.honeypot {
    position: absolute;
    left: -9999px;
    width: 1px;
    height: 1px;
    overflow: hidden;
}
.email-error {
    color: var(--color-error);
    font-size: var(--font-size-small);
    font-weight: var(--font-weight-bold);
}
.email-result {
    margin-top: calc(var(--spacing-unit) * 4);
    padding: calc(var(--spacing-unit) * 5);
    background-color: var(--color-accent-light);
    border: 1px solid var(--color-accent);
    border-radius: var(--border-radius);
    color: var(--color-text);
}
.email-result strong {
    color: var(--color-success);
}
.email-note {
    font-size: var(--font-size-small);
    color: var(--color-text-secondary);
    margin-top: calc(var(--spacing-unit) * 4);
}

/* ===== Footer ===== */
.footer {
    padding: calc(var(--spacing-unit) * 12) 0 calc(var(--spacing-unit) * 8);
    background-color: var(--color-surface);
    border-top: 1px solid var(--color-border);
}
.footer-inner {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: calc(var(--spacing-unit) * 5);
}
.footer-title {
    font-size: var(--font-size-large);
    font-weight: var(--font-weight-bold);
    margin-bottom: calc(var(--spacing-unit) * 2);
}
.footer-cta p {
    color: var(--color-text-secondary);
    margin-bottom: calc(var(--spacing-unit) * 4);
    max-width: 520px;
}
.footer-meta {
    font-size: var(--font-size-small);
    color: var(--color-text-secondary);
}

/* ===== Responsive ===== */
@media (max-width: 1023px) {
    .calculator-container {
        gap: calc(var(--spacing-unit) * 4);
    }
}

@media (max-width: 767px) {
    .container {
        padding: 0 calc(var(--spacing-unit) * 4);
    }
    .hero {
        padding: calc(var(--spacing-unit) * 10) 0 calc(var(--spacing-unit) * 8);
    }
    .hero-title {
        font-size: 32px;
    }
    .hero-subtitle {
        font-size: var(--font-size-base);
    }
    .hero-stat-number {
        font-size: 72px;
    }
    .calculator-container {
        flex-direction: column;
        gap: calc(var(--spacing-unit) * 4);
    }
    .input-panel, .result-panel {
        padding: calc(var(--spacing-unit) * 5);
    }
    .result-cards {
        flex-direction: column;
        gap: calc(var(--spacing-unit) * 3);
    }
    .radio-group, .checkbox-group {
        flex-direction: column;
        gap: calc(var(--spacing-unit) * 2);
    }
    .calculate-button, .cta-button {
        width: 100%;
    }
    .hero-content .cta-button {
        max-width: 320px;
    }
    /* Larger touch target for slider thumbs on mobile */
    .slider::-webkit-slider-thumb {
        width: 44px;
        height: 44px;
    }
    .slider::-moz-range-thumb {
        width: 44px;
        height: 44px;
    }
    .slider {
        height: 6px;
    }
    .chart-wrap {
        height: 240px;
    }
    .payback-badge {
        flex-direction: column;
        align-items: flex-start;
        gap: calc(var(--spacing-unit) * 1);
    }
}

@media (max-width: 479px) {
    .hero-stat-number {
        font-size: 56px;
    }
    .chart-wrap {
        height: 200px;
    }
    .table-scroll {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }
    .comparison-table table {
        min-width: 420px;
    }
}

@media (prefers-reduced-motion: reduce) {
    .result-summary {
        animation: none;
    }
    * {
        transition: none !important;
    }
}