:root {
    --bg: #f7f8fa;
    --surface: #ffffff;
    --ink: #0f172a;
    --ink-soft: #475569;
    --ink-faint: #94a3b8;
    --line: #e2e8f0;
    --line-strong: #cbd5e1;
    --accent: #0f766e;
    --accent-strong: #115e59;
    --accent-soft: #ccfbf1;
    --danger-bg: #fef2f2;
    --danger-ink: #991b1b;
    --danger-line: #fecaca;
    --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.04);
    --shadow-md: 0 4px 16px rgba(15, 23, 42, 0.06);
    --radius: 12px;
    --radius-sm: 8px;
}

* { box-sizing: border-box; }

html, body {
    margin: 0;
    padding: 0;
    background: var(--bg);
    color: var(--ink);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.55;
    -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-strong); }

.container {
    max-width: 1080px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* ── nav ─────────────────────────────────────────────── */

.topnav {
    background: var(--surface);
    border-bottom: 1px solid var(--line);
}
.topnav .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}
.brand {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    color: var(--ink);
    font-weight: 700;
    font-size: 1.05rem;
    letter-spacing: -0.01em;
}
.brand:hover { color: var(--ink); }
.logo-mark {
    display: inline-grid;
    place-items: center;
    width: 30px;
    height: 30px;
    border-radius: 8px;
    background: var(--accent);
    color: #fff;
    font-size: 0.78rem;
    letter-spacing: 0.04em;
}
.nav-tag {
    color: var(--ink-faint);
    font-size: 0.85rem;
    font-weight: 500;
}

/* ── hero ────────────────────────────────────────────── */

.hero {
    padding: 2.75rem 0 2rem;
    background: linear-gradient(180deg, var(--surface) 0%, var(--bg) 100%);
    border-bottom: 1px solid var(--line);
}
.hero .container { max-width: 1240px; }
.demo-result {
    padding: 2.5rem 0 1rem;
    border-bottom: 1px solid var(--line);
}
.demo-result h2 {
    margin: 0 0 0.5rem;
    font-size: 1.6rem;
    letter-spacing: -0.01em;
}
.demo-ready-title {
    color: var(--accent);
}

/* Staged reveal animation when the demo is first shown */
.demo-result .eyebrow,
.demo-result h2,
.demo-result > .container > .lede,
.demo-result .actions-top,
.demo-result .product-card-head,
.demo-result .product-callouts,
.demo-result .diagnostics {
    opacity: 0;
}
@keyframes demoFadeUp {
    from { opacity: 0; transform: translateY(8px); }
    to   { opacity: 1; transform: translateY(0); }
}
@keyframes demoDrawLine { to { stroke-dashoffset: 0; } }
@keyframes demoFadeIn   { to { opacity: 1; } }

.demo-result.is-revealed .eyebrow              { animation: demoFadeUp 0.4s ease-out 0.00s forwards; }
.demo-result.is-revealed h2                    { animation: demoFadeUp 0.5s ease-out 0.08s forwards; }
.demo-result.is-revealed > .container > .lede  { animation: demoFadeUp 0.5s ease-out 0.16s forwards; }
.demo-result.is-revealed .actions-top          { animation: demoFadeUp 0.5s ease-out 0.24s forwards; }
.demo-result.is-revealed .product-card-head    { animation: demoFadeUp 0.5s ease-out 0.32s forwards; }
.demo-result.is-revealed .product-callouts     { animation: demoFadeUp 0.5s ease-out 0.40s forwards; }
.demo-result.is-revealed .diagnostics          { animation: demoFadeUp 0.5s ease-out 4.6s forwards; }

/* Chart line drawing */
.demo-chart {
    width: 100%;
    height: auto;
    display: block;
    font-family: 'Inter', system-ui, sans-serif;
}
.demo-chart-grid {
    stroke: var(--line);
    stroke-width: 1;
    stroke-dasharray: 2 4;
    opacity: 0;
}
.demo-chart-axis {
    fill: var(--ink-faint);
    font-size: 11px;
    opacity: 0;
}
.demo-chart-axis-small { font-size: 10px; opacity: 0; }
.demo-chart-divider {
    stroke: var(--ink-faint);
    stroke-dasharray: 3 3;
    stroke-width: 1;
    opacity: 0;
}
.demo-chart-divider-label {
    fill: #0072b2;
    font-size: 11px;
    font-weight: 600;
    opacity: 0;
}
.demo-chart-band {
    fill: #0072b2;
    fill-opacity: 0.14;
    opacity: 0;
}
.demo-chart-forecast {
    fill: none;
    stroke-linejoin: round;
    stroke-linecap: round;
    stroke-dasharray: 1;
    stroke-dashoffset: 1;
    stroke: #0072b2;
    stroke-width: 2.2;
    vector-effect: non-scaling-stroke;
}
.demo-chart-imputed {
    fill: #dc2626;
    opacity: 0;
}
.demo-chart-point {
    fill: var(--ink);
    fill-opacity: 0.85;
    opacity: 0;
}

.demo-result.is-revealed .demo-chart-grid,
.demo-result.is-revealed .demo-chart-axis,
.demo-result.is-revealed .demo-chart-divider {
    animation: demoFadeIn 0.5s ease 0.45s forwards;
}
.demo-result.is-revealed .demo-chart-point {
    animation: demoFadeIn 0.45s ease forwards;
}
.demo-result.is-revealed .demo-chart-imputed {
    animation: demoFadeIn 0.45s ease forwards;
}
.demo-result.is-revealed .demo-chart-forecast {
    animation: demoDrawLine 2.0s cubic-bezier(0.65, 0, 0.35, 1) 2.1s forwards;
}
.demo-result.is-revealed .demo-chart-band {
    animation: demoFadeIn 0.6s ease 4.0s forwards;
}
.demo-result.is-revealed .demo-chart-divider-label {
    animation: demoFadeIn 0.5s ease 1.6s forwards;
}

@media (prefers-reduced-motion: reduce) {
    .demo-result .eyebrow,
    .demo-result h2,
    .demo-result > .container > .lede,
    .demo-result .actions-top,
    .demo-result .product-card-head,
    .demo-result .product-callouts,
    .demo-result .diagnostics { opacity: 1; }
    .demo-chart-grid,
    .demo-chart-axis,
    .demo-chart-divider,
    .demo-chart-divider-label,
    .demo-chart-band { opacity: 1; }
    .demo-chart-forecast { stroke-dashoffset: 0; }
    .demo-result.is-revealed * { animation: none !important; }
}
.hero-grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
    gap: 2.5rem;
    align-items: center;
}
.hero-text { min-width: 0; }
.hero-cta {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 1.75rem 1.75rem 1.5rem;
    box-shadow: var(--shadow-md);
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
    min-width: 0;
}
.hero-cta-eyebrow {
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-size: 0.72rem;
    font-weight: 600;
    margin: 0;
}
.hero-cta h2 {
    margin: 0;
    font-size: 1.5rem;
    letter-spacing: -0.01em;
}
.hero-cta p {
    margin: 0;
    color: var(--ink-soft);
    font-size: 0.98rem;
    line-height: 1.5;
}
.hero-cta-btn {
    align-self: flex-start;
    margin-top: 0.4rem;
}
.hero-cta-hint {
    color: var(--ink-faint);
    font-size: 0.8rem;
    margin: 0.25rem 0 0;
}
.eyebrow {
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-size: 0.75rem;
    font-weight: 600;
    margin: 0 0 0.75rem;
}
.hero h1 {
    font-size: clamp(2rem, 4vw, 3rem);
    margin: 0 0 1rem;
    letter-spacing: -0.02em;
    line-height: 1.1;
    max-width: 22ch;
}
.lede {
    font-size: 1.05rem;
    color: var(--ink-soft);
    max-width: 60ch;
    margin: 0 0 0.5rem;
}

/* ── buttons ─────────────────────────────────────────── */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.7rem 1.25rem;
    border-radius: 9999px;
    font-weight: 600;
    font-size: 0.95rem;
    border: 1px solid transparent;
    cursor: pointer;
    transition: background 120ms ease, color 120ms ease, border-color 120ms ease, transform 80ms ease;
    line-height: 1;
    font-family: inherit;
}
.btn-primary {
    background: var(--accent);
    color: #fff;
}
.btn-primary:hover { background: var(--accent-strong); color: #fff; }
.btn-primary:active { transform: translateY(1px); }
.btn-ghost {
    background: transparent;
    color: var(--ink);
    border-color: var(--line-strong);
    margin-left: 0.6rem;
}
.btn-ghost:hover { background: var(--surface); color: var(--ink); border-color: var(--ink-faint); }
.btn-secondary {
    background: var(--surface);
    color: var(--accent-strong);
    border-color: var(--accent);
}
.btn-secondary:hover { background: var(--accent-soft); color: var(--accent-strong); }
.btn[disabled],
form.submitting .btn {
    opacity: 0.7;
    cursor: progress;
}

.submit-spinner {
    display: none;
    width: 14px;
    height: 14px;
    border: 2px solid rgba(255,255,255,0.45);
    border-top-color: #fff;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}
.btn-secondary .submit-spinner {
    border-color: rgba(15, 118, 110, 0.25);
    border-top-color: var(--accent);
}
form.submitting .submit-spinner { display: inline-block; }
form.submitting .submit-label::after { content: '…'; }

@keyframes spin {
    to { transform: rotate(360deg); }
}

.submit-row {
    display: flex;
    align-items: center;
    gap: 1rem;
}
.submit-progress {
    display: none;
    flex: 1;
    min-width: 200px;
    height: 8px;
    background: var(--line);
    border-radius: 999px;
    overflow: hidden;
}
.submit-progress-bar {
    width: 40%;
    height: 100%;
    background: linear-gradient(90deg, var(--accent), var(--accent-strong));
    border-radius: 999px;
    animation: indeterminate 1.4s ease-in-out infinite;
}
form.submitting .submit-progress { display: block; }

@keyframes indeterminate {
    0%   { margin-left: -40%; }
    100% { margin-left: 100%; }
}

/* ── value section ───────────────────────────────────── */

.value {
    padding: 3rem 0;
}
.value-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.25rem;
}
.value-card {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
}
.value-card h3 {
    margin: 0 0 0.5rem;
    font-size: 1.05rem;
    letter-spacing: -0.01em;
}
.value-card p {
    margin: 0;
    color: var(--ink-soft);
    font-size: 0.95rem;
}

/* ── how-it-works ────────────────────────────────────── */

.how {
    padding: 3rem 0 4rem;
    background: var(--surface);
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
}
.how h2 {
    font-size: 1.6rem;
    letter-spacing: -0.01em;
    margin: 0 0 1.75rem;
}
.steps {
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}
.steps li {
    display: block;
}
.step-num {
    display: inline-grid;
    place-items: center;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--accent-soft);
    color: var(--accent-strong);
    font-weight: 700;
    margin-bottom: 0.75rem;
}
.steps h4 {
    margin: 0 0 0.4rem;
    font-size: 1rem;
}
.steps p {
    margin: 0;
    color: var(--ink-soft);
    font-size: 0.95rem;
}

/* ── start (form) ────────────────────────────────────── */

.start { padding: 1rem 0 4rem; }
.start h2 {
    font-size: 1.2rem;
    letter-spacing: -0.01em;
    margin: 0 0 0.75rem;
}

.forecast-form {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
}

.csv-preview {
    background: #fbfcfd;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 1rem 1.25rem 1.1rem;
    margin: 0 0 1rem;
}
.csv-preview-head {
    display: flex;
    flex-wrap: wrap;
    align-items: baseline;
    justify-content: space-between;
    gap: 0.5rem 1rem;
    margin-bottom: 0.7rem;
}
.csv-preview-title {
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--ink);
    text-transform: uppercase;
    letter-spacing: 0.06em;
}
.csv-preview-hint {
    font-size: 0.78rem;
    color: var(--ink-faint);
}
.csv-preview-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    font-family: 'SF Mono', SFMono-Regular, Menlo, Consolas, monospace;
    font-size: 0.85rem;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius-sm);
    overflow: hidden;
}
.csv-preview-table th,
.csv-preview-table td {
    padding: 0.45rem 0.85rem;
    border-bottom: 1px solid var(--line);
    border-right: 1px solid var(--line);
    text-align: left;
    color: var(--ink);
}
.csv-preview-table th:last-child,
.csv-preview-table td:last-child { border-right: none; }
.csv-preview-table tbody tr:last-child td { border-bottom: none; }
.csv-preview-table th {
    background: var(--accent-soft);
    color: var(--accent-strong);
    font-weight: 600;
    letter-spacing: 0.01em;
}
.csv-preview-ellipsis td {
    color: var(--ink-faint);
    text-align: center;
    letter-spacing: 0.2em;
}

.dropzone {
    position: relative;
    border: 2px dashed var(--line-strong);
    border-radius: var(--radius);
    padding: 2.25rem 1.5rem;
    text-align: center;
    color: var(--ink-soft);
    transition: border-color 120ms ease, background 120ms ease;
    cursor: pointer;
    background: #fbfcfd;
}
.dropzone:hover,
.dropzone:focus { border-color: var(--accent); color: var(--ink); outline: none; }
.dropzone.dragover { border-color: var(--accent); background: var(--accent-soft); color: var(--ink); }
.dropzone.has-file { border-style: solid; border-color: var(--accent); background: var(--surface); }
.dropzone input[type="file"] {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    cursor: pointer;
}
.dropzone-content { pointer-events: none; }
.dropzone-title {
    font-size: 1rem;
    color: var(--ink);
    font-weight: 600;
    margin: 0.5rem 0 0.25rem;
}
.dropzone-hint {
    font-size: 0.85rem;
    color: var(--ink-faint);
    margin: 0;
}
.dropzone-file {
    margin: 0.75rem 0 0;
    font-size: 0.9rem;
    color: var(--accent-strong);
    font-weight: 600;
}

.row {
    display: flex;
    align-items: end;
    gap: 1.25rem;
    margin-top: 1.25rem;
    flex-wrap: wrap;
}
.field {
    display: block;
    flex: 1 1 220px;
}
.field span {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--ink);
    margin-bottom: 0.4rem;
}
.field input[type="number"] {
    width: 100%;
    padding: 0.65rem 0.85rem;
    font-size: 1rem;
    border: 1px solid var(--line-strong);
    border-radius: var(--radius-sm);
    background: var(--surface);
    font-family: inherit;
    transition: border-color 120ms ease, box-shadow 120ms ease;
}
.field input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-soft);
}
.field small {
    display: block;
    color: var(--ink-faint);
    font-size: 0.78rem;
    margin-top: 0.3rem;
}
.field-optional {
    color: var(--ink-faint);
    font-weight: 500;
    font-size: 0.78rem;
    letter-spacing: 0.02em;
    margin-left: 0.3rem;
}
.btn-submit { padding: 0.85rem 1.5rem; }
.form-note {
    color: var(--ink-faint);
    font-size: 0.85rem;
    margin: 1rem 0 0;
}

/* ── error ───────────────────────────────────────────── */

.error {
    background: var(--danger-bg);
    color: var(--danger-ink);
    border: 1px solid var(--danger-line);
    border-radius: var(--radius-sm);
    padding: 0.75rem 1rem;
    margin: 0 0 1rem;
    font-size: 0.92rem;
}

/* ── examples ────────────────────────────────────────── */

.examples {
    padding: 1.5rem 0 0;
}
.examples h2 {
    font-size: 1.2rem;
    margin: 0 0 0.75rem;
    letter-spacing: -0.01em;
}
.example-card {
    display: flex;
    align-items: center;
    gap: 1.25rem;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 1.1rem 1.25rem;
    box-shadow: var(--shadow-sm);
}
.example-info { flex: 1; }
.example-info h4 {
    margin: 0 0 0.25rem;
    font-size: 1rem;
}
.example-info p {
    margin: 0;
    color: var(--ink-soft);
    font-size: 0.9rem;
}

/* ── result page ─────────────────────────────────────── */

.result { padding: 4rem 0 5rem; }
.result h1 {
    font-size: clamp(1.6rem, 3vw, 2.25rem);
    letter-spacing: -0.02em;
    margin: 0 0 0.75rem;
}
.callouts {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin: 2rem 0 1.5rem;
}
.product-callouts {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.85rem;
    margin: 0 0 1.1rem;
}
.product-card {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    margin: 1.5rem 0;
}
.product-card-head {
    margin: 0 0 1.1rem;
}
.product-card-head h2,
.product-card-head h3 {
    margin: 0;
    font-size: 1.25rem;
    letter-spacing: -0.01em;
}
.result-header {
    margin: 0 0 1.5rem;
}
.result-header h2 {
    margin: 0 0 0.4rem;
    font-size: 1.6rem;
    letter-spacing: -0.01em;
}
.product-card-meta {
    margin: 0.25rem 0 0;
    font-size: 0.85rem;
    color: var(--ink-faint);
}
.actions-top { margin: 1rem 0 1.5rem; }
.callout {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 1rem 1.25rem;
    box-shadow: var(--shadow-sm);
}
.callout-label {
    margin: 0;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--ink-faint);
    font-weight: 600;
}
.callout-value {
    margin: 0.4rem 0 0.2rem;
    font-size: 1.4rem;
    font-weight: 700;
    letter-spacing: -0.01em;
    color: var(--ink);
}
.callout-hint {
    margin: 0;
    font-size: 0.78rem;
    color: var(--ink-soft);
}
.result-card {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 1rem;
    box-shadow: var(--shadow-md);
    margin: 0.5rem 0 1.25rem;
}
.result-card img {
    display: block;
    width: 100%;
    height: auto;
    border-radius: var(--radius-sm);
}
.actions { display: flex; gap: 0; align-items: center; }
.diagnostics {
    margin-top: 2rem;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 1rem 1.25rem;
}
.diagnostics summary {
    cursor: pointer;
    font-weight: 600;
    color: var(--ink);
    list-style: none;
}
.diagnostics summary::-webkit-details-marker { display: none; }
.diagnostics summary::after {
    content: ' ▾';
    color: var(--ink-faint);
    font-size: 0.8rem;
}
.diagnostics[open] summary::after { content: ' ▴'; }
.diagnostics dl {
    display: grid;
    grid-template-columns: max-content 1fr;
    gap: 0.4rem 1.25rem;
    margin: 1rem 0 0;
    font-size: 0.92rem;
}
.diagnostics dt { color: var(--ink-faint); }
.diagnostics dd { margin: 0; color: var(--ink); }

/* ── footer ──────────────────────────────────────────── */

footer {
    border-top: 1px solid var(--line);
    background: var(--surface);
    padding: 1.5rem 0;
    margin-top: auto;
}
footer p {
    margin: 0;
    color: var(--ink-soft);
    font-size: 0.85rem;
    opacity: 0.75;
}

.accent-text {
    color: var(--accent);
    font-weight: 600;
}

.legal {
    padding: 3rem 0 4rem;
}
.legal .container { max-width: 760px; }
.legal h1 {
    font-size: 2rem;
    margin: 0 0 0.25rem;
}
.legal .legal-meta {
    color: var(--ink-faint);
    font-size: 0.9rem;
    margin: 0 0 2rem;
}
.legal h2 {
    font-size: 1.15rem;
    margin: 2rem 0 0.5rem;
}
.legal p, .legal li {
    color: var(--ink-soft);
    line-height: 1.6;
}
.legal ul {
    padding-left: 1.25rem;
    margin: 0.5rem 0 1rem;
}
.legal li { margin-bottom: 0.4rem; }
.legal a { color: var(--accent); }

footer a {
    color: var(--ink-soft);
    text-decoration: underline;
}
footer a:hover { color: var(--ink); }

/* ── responsive ──────────────────────────────────────── */

@media (max-width: 760px) {
    .value-grid, .steps, .callouts, .product-callouts {
        grid-template-columns: 1fr;
    }
    .hero { padding: 2rem 0 1.5rem; }
    .hero-grid { grid-template-columns: 1fr; gap: 1.5rem; }
    .btn-ghost { margin-left: 0; margin-top: 0.5rem; }
    .row { flex-direction: column; align-items: stretch; }
    .btn-submit { width: 100%; }
    .example-card { flex-direction: column; align-items: stretch; text-align: left; }

    /* Hide the navbar tagline; cramped next to brand on small screens. */
    .nav-tag { display: none; }

    /* Let the CSV preview table scroll horizontally instead of bleeding off-screen. */
    .csv-preview { overflow-x: auto; -webkit-overflow-scrolling: touch; }
    .csv-preview-table { min-width: 22rem; }

    /* Submit-row column layout — make progress bar span full width under the button. */
    .submit-progress { width: 100%; min-width: 0; }

    /* Diagnostics: stack the dt/dd pairs into a single column. */
    .diagnostics dl { grid-template-columns: 1fr; gap: 0.25rem; }
    .diagnostics dt { margin-top: 0.5rem; }

    /* Top callouts stack to single column already via .product-callouts; tighten gap. */
    .product-callouts { gap: 0.75rem; }
}

@media (max-width: 420px) {
    .container { padding: 0 1rem; }
    .legal h1 { font-size: 1.6rem; }
    .demo-result h2 { font-size: 1.35rem; }
}