/* =========================================================
   Tokens
   ========================================================= */
:root {
  --bg: #F1F2F5;
  --card-bg: #FFFFFF;
  --ink: #14161A;
  --ink-muted: #5B6472;
  --border: #E2E4E9;
  --border-soft: #ECEDF1;
  --accent: #2F3E9E;
  --accent-dark: #232F7D;
  --accent-tint: #EAECFB;
  --marker: #E7A33D;
  --marker-tint: #FBEDD6;
  --error: #C63E3E;
  --error-tint: #FBEAEA;

  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, monospace;

  --radius-lg: 18px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --shadow-card: 0 1px 2px rgba(20, 22, 26, 0.04), 0 10px 30px -12px rgba(20, 22, 26, 0.10);
}

/* =========================================================
   Reset & base
   ========================================================= */
* { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  background-image:
    radial-gradient(circle at 1px 1px, rgba(20,22,26,0.045) 1px, transparent 0);
  background-size: 22px 22px;
  color: var(--ink);
  font-family: var(--font-body);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    transition-duration: 0.001ms !important;
  }
}

/* =========================================================
   Layout shell
   ========================================================= */
.page {
  max-width: 640px;
  margin: 0 auto;
  padding: 28px 20px 64px;
}

.site-header {
  text-align: center;
  margin-bottom: 22px;
}

.eyebrow {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 700;
}

.site-tagline {
  margin: 0;
  font-size: 15px;
  color: var(--ink-muted);
  font-weight: 500;
}

/* =========================================================
   Ad slots
   ========================================================= */
.ad-slot {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 90px;
  margin: 18px 0;
  border: 1.5px dashed #C7CAD3;
  border-radius: var(--radius-md);
  background: repeating-linear-gradient(
    135deg,
    rgba(20,22,26,0.02),
    rgba(20,22,26,0.02) 10px,
    transparent 10px,
    transparent 20px
  );
  color: #9198A6;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* =========================================================
   Tool card
   ========================================================= */
.tool-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  padding: 26px 22px 24px;
}

.inputs-row {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 10px;
  align-items: end;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.field label {
  font-size: 12.5px;
  font-weight: 600;
  color: var(--ink-muted);
}

.field input[type="date"] {
  width: 100%;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 500;
  color: var(--ink);
  background: #FAFAFB;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 11px 10px;
  transition: border-color 0.15s ease, background 0.15s ease;
}

.field input[type="date"]:hover {
  border-color: #C7CAD3;
}

.field input[type="date"]:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
  border-color: var(--accent);
  background: #fff;
}

.swap-wrap {
  display: flex;
  justify-content: center;
  padding-bottom: 2px;
}

.swap-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: 999px;
  border: 1.5px solid var(--border);
  background: #FAFAFB;
  color: var(--accent);
  cursor: pointer;
  transition: background 0.15s ease, transform 0.15s ease, border-color 0.15s ease;
}

.swap-btn:hover {
  background: var(--accent-tint);
  border-color: var(--accent);
}

.swap-btn:active {
  transform: rotate(180deg);
}

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

.error-message {
  min-height: 18px;
  margin: 12px 2px 0;
  font-size: 13px;
  font-weight: 600;
  color: var(--error);
}

.error-message:empty {
  margin: 0;
}

/* =========================================================
   Signature element: the timeline ruler
   ========================================================= */
.ruler-wrap {
  margin-top: 22px;
  padding-top: 4px;
}

.ruler-track {
  position: relative;
  height: 34px;
  border-radius: 999px;
  background: #F0F1F4;
  border: 1px solid var(--border-soft);
  overflow: hidden;
}

.ruler-ticks {
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(
    90deg,
    rgba(20,22,26,0.10) 0,
    rgba(20,22,26,0.10) 1px,
    transparent 1px,
    transparent calc(100% / 28)
  );
}

.ruler-fill {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 0%;
  background: linear-gradient(90deg, var(--accent-tint), var(--marker-tint));
  transition: width 0.5s cubic-bezier(0.22, 1, 0.36, 1);
}

.ruler-marker {
  position: absolute;
  top: 3px;
  bottom: 3px;
  width: 3px;
  border-radius: 3px;
  background: var(--accent);
  left: 0%;
  transition: left 0.5s cubic-bezier(0.22, 1, 0.36, 1);
}

.ruler-marker--end {
  background: var(--marker);
}

.ruler-labels {
  display: flex;
  justify-content: space-between;
  margin-top: 7px;
  padding: 0 2px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--ink-muted);
}

/* =========================================================
   Results
   ========================================================= */
.results {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 22px;
}

.result-stat {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding: 16px 14px;
  background: #FAFAFB;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-md);
}

.result-stat--primary {
  grid-column: 1 / -1;
  background: var(--accent-dark);
  border-color: var(--accent-dark);
}

.result-stat--primary .result-value {
  color: #fff;
  font-size: 46px;
}

.result-stat--primary .result-label {
  color: #C7CDF2;
}

.result-value {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 22px;
  color: var(--ink);
  letter-spacing: -0.01em;
  font-variant-numeric: tabular-nums;
}

.result-label {
  font-size: 12.5px;
  font-weight: 600;
  color: var(--ink-muted);
}

/* =========================================================
   Info / SEO content section
   ========================================================= */
.info-section {
  margin-top: 34px;
  padding-top: 4px;
}

.info-section h2 {
  font-size: 19px;
  font-weight: 700;
  margin: 30px 0 10px;
  color: var(--ink);
}

.info-section h2:first-child {
  margin-top: 0;
}

.info-section h3 {
  font-size: 15.5px;
  font-weight: 700;
  margin: 18px 0 6px;
  color: var(--ink);
}

.info-section p {
  margin: 0 0 12px;
  font-size: 14.5px;
  color: var(--ink-muted);
}

/* =========================================================
   Footer
   ========================================================= */
.site-footer {
  margin-top: 40px;
  text-align: center;
  font-size: 12.5px;
  color: #9198A6;
}

/* =========================================================
   Responsive
   ========================================================= */
@media (max-width: 480px) {
  .page {
    padding: 20px 14px 48px;
  }

  .tool-card {
    padding: 20px 16px 18px;
  }

  .inputs-row {
    grid-template-columns: 1fr;
  }

  .swap-wrap {
    padding: 2px 0;
  }

  .swap-btn {
    margin: 0 auto;
    transform: rotate(90deg);
  }

  .swap-btn:active {
    transform: rotate(270deg);
  }

  .results {
    grid-template-columns: 1fr;
  }

  .result-stat--primary .result-value {
    font-size: 40px;
  }
}

@media (min-width: 481px) and (max-width: 640px) {
  .result-stat--primary .result-value {
    font-size: 42px;
  }
}