:root {
  color-scheme: light;
  --bg: #f6f8f7;
  --surface: #ffffff;
  --text: #1f2a2a;
  --muted: #5e6b69;
  --line: #dbe4e1;
  --accent: #24736b;
  --accent-dark: #185a54;
  --accent-soft: #e5f3f0;
  --warning: #8a5a00;
  --warning-bg: #fff6dd;
  --error: #b42318;
  --error-bg: #fff0ef;
  --shadow: 0 18px 45px rgba(31, 42, 42, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 16px;
  line-height: 1.5;
}

main {
  width: 100%;
}

.tool-ui {
  min-height: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 28px 16px 18px;
}

.hero {
  width: min(100%, 760px);
  margin-bottom: 18px;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--accent-dark);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1 {
  margin: 0;
  font-size: 2rem;
  line-height: 1.12;
  letter-spacing: 0;
}

.intro {
  max-width: 680px;
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 1.02rem;
}

.calculator-card {
  width: min(100%, 760px);
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.field-group {
  display: grid;
  gap: 8px;
}

label {
  font-weight: 700;
}

input[type="date"] {
  width: 100%;
  min-height: 48px;
  padding: 10px 12px;
  color: var(--text);
  background: #ffffff;
  border: 1px solid #b9c8c4;
  border-radius: 6px;
  font: inherit;
}

input[type="date"]:focus {
  outline: 3px solid rgba(36, 115, 107, 0.18);
  border-color: var(--accent);
}

.field-help {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.error-message,
.warning-message,
.copy-status {
  margin: 12px 0 0;
  font-size: 0.94rem;
}

.error-message:not(:empty),
.warning-message:not(:empty) {
  padding: 10px 12px;
  border-radius: 6px;
}

.error-message:not(:empty) {
  color: var(--error);
  background: var(--error-bg);
}

.warning-message:not(:empty) {
  color: var(--warning);
  background: var(--warning-bg);
}

.actions {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin-top: 18px;
}

button {
  min-height: 46px;
  padding: 11px 16px;
  border-radius: 6px;
  border: 1px solid transparent;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}

.primary-button {
  color: #ffffff;
  background: var(--accent);
}

.primary-button:hover,
.primary-button:focus {
  background: var(--accent-dark);
}

.secondary-button,
.copy-button {
  color: var(--accent-dark);
  background: #ffffff;
  border-color: #abc4bf;
}

.secondary-button:hover,
.secondary-button:focus,
.copy-button:hover,
.copy-button:focus {
  background: var(--accent-soft);
}

.result-panel {
  margin-top: 20px;
  padding: 16px;
  background: #f9fbfa;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.result-panel h2 {
  margin: 0 0 12px;
  font-size: 1.25rem;
}

.result-lines {
  display: grid;
  gap: 8px;
}

.result-line {
  margin: 0;
  font-size: 1.02rem;
}

.result-line strong {
  color: var(--text);
}

.disclaimer {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.copy-button {
  width: 100%;
  margin-top: 14px;
}

.copy-status {
  min-height: 1.4em;
  color: var(--accent-dark);
}

.seo-content,
.faq-section {
  width: min(100% - 32px, 760px);
  margin: 22px auto 0;
}

.seo-content h2,
.faq-section h2 {
  margin: 0 0 12px;
  font-size: 1.38rem;
}

.seo-content p {
  margin: 0 0 12px;
  color: var(--muted);
}

details {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  margin-bottom: 10px;
}

summary {
  padding: 14px 16px;
  font-weight: 700;
  cursor: pointer;
}

details p {
  margin: 0;
  padding: 0 16px 16px;
  color: var(--muted);
}

.site-footer {
  width: min(100% - 32px, 760px);
  margin: 26px auto 0;
  padding: 20px 0 28px;
  color: var(--muted);
  font-size: 0.92rem;
}

.site-footer p {
  margin: 0;
}

@media (min-width: 620px) {
  .tool-ui {
    padding-top: 42px;
  }

  h1 {
    font-size: 2.65rem;
  }

  .calculator-card {
    padding: 26px;
  }

  .actions {
    grid-template-columns: 1fr auto;
  }

  .secondary-button {
    min-width: 120px;
  }

  .copy-button {
    width: auto;
  }
}