:root {
  color-scheme: light;
  --bg: #f7f8fb;
  --surface: #ffffff;
  --surface-soft: #eef4f0;
  --text: #16211d;
  --muted: #65716c;
  --border: #dce5df;
  --accent: #217a63;
  --accent-dark: #155d4b;
  --accent-soft: #dff2ec;
  --warning: #8a4b10;
  --error: #b42318;
  --shadow: 0 18px 50px rgba(22, 33, 29, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family:
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
  font-size: 16px;
  line-height: 1.5;
}

a {
  color: inherit;
}

button,
input {
  font: inherit;
}

.site-header,
.site-footer,
.page {
  width: calc(100% - 32px);
  max-width: 820px;
  margin-inline: auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: 18px 8px;
}

.brand,
.back-link {
  color: var(--muted);
  font-size: 0.95rem;
  font-weight: 700;
  text-decoration: none;
}

.brand:hover,
.back-link:hover {
  color: var(--accent-dark);
}

.page {
  padding-block: 18px 46px;
}

.home-page {
  display: grid;
  gap: 28px;
}

.intro {
  padding-top: 14px;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--accent);
  font-size: 0.86rem;
  font-weight: 800;
  letter-spacing: 0;
}

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

h1 {
  margin: 0;
  font-size: 2.45rem;
  line-height: 1;
  letter-spacing: 0;
}

.lead {
  max-width: 34rem;
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 1.1rem;
}

.section-title {
  margin: 0 0 12px;
  color: var(--muted);
  font-size: 0.86rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.feature-link {
  display: flex;
  min-height: 96px;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
  padding: 20px;
  text-decoration: none;
}

.feature-link strong,
.feature-link small {
  display: block;
}

.feature-link strong {
  font-size: 1.25rem;
}

.feature-link small {
  margin-top: 4px;
  color: var(--muted);
  font-size: 0.98rem;
}

.feature-link:hover,
.feature-link:focus-visible {
  border-color: var(--accent);
  outline: none;
}

.feature-arrow {
  display: grid;
  width: 42px;
  height: 42px;
  flex: 0 0 auto;
  place-items: center;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent-dark);
  font-size: 1.35rem;
}

.planned {
  padding-top: 4px;
}

.quiet-list {
  display: grid;
  gap: 8px;
  margin: 0;
  padding: 0;
  color: var(--muted);
  list-style: none;
}

.quiet-list li {
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
}

.calculator-page {
  display: grid;
  gap: 22px;
}

.calculator-hero {
  display: grid;
  gap: 10px;
}

.calculator-hero h1 {
  font-size: 2.35rem;
}

.calculator {
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
  padding: 18px;
}

.calculator-form {
  display: grid;
  gap: 16px;
}

.form-grid {
  display: grid;
  gap: 14px;
}

.field,
.time-fieldset {
  display: grid;
  gap: 7px;
}

.field label,
.time-fieldset legend {
  color: var(--text);
  font-size: 0.94rem;
  font-weight: 800;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

.field input,
.time-inputs input {
  width: 100%;
  min-height: 54px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  color: var(--text);
  padding: 12px 14px;
  font-size: 1.1rem;
}

.time-inputs input {
  padding-right: 52px;
}

.field input:focus,
.time-inputs input:focus {
  border-color: var(--accent);
  outline: 3px solid var(--accent-soft);
}

.time-fieldset {
  min-width: 0;
  margin: 0;
  border: 0;
  padding: 0;
}

.time-inputs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.time-inputs label {
  position: relative;
  display: block;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 700;
}

.time-unit {
  position: absolute;
  right: 12px;
  top: 50%;
  color: var(--muted);
  pointer-events: none;
  transform: translateY(-50%);
}

.primary-button {
  width: 100%;
  min-height: 58px;
  border: 0;
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  cursor: pointer;
  font-size: 1.08rem;
  font-weight: 800;
}

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

.primary-button:focus-visible {
  outline: 4px solid var(--accent-soft);
  outline-offset: 3px;
}

.message {
  min-height: 1.5em;
  margin: -4px 0 0;
  color: var(--error);
  font-weight: 700;
}

.message:empty {
  display: none;
}

.result {
  display: none;
  gap: 8px;
  border-radius: 8px;
  background: var(--surface-soft);
  padding: 16px;
}

.result.is-visible {
  display: grid;
}

.result-title {
  margin: 0;
  color: var(--accent-dark);
  font-size: 1.55rem;
  font-weight: 900;
  line-height: 1.15;
}

.result-example,
.notice {
  margin: 0;
  color: var(--muted);
}

.notice {
  border-left: 4px solid #f2b84b;
  padding-left: 12px;
  color: var(--warning);
  font-size: 0.95rem;
}

.content {
  display: grid;
  gap: 28px;
  margin-top: 12px;
  padding-top: 28px;
  border-top: 1px solid var(--border);
}

.content section {
  display: grid;
  gap: 10px;
}

.content h2 {
  margin: 0;
  font-size: 1.45rem;
  line-height: 1.15;
}

.content h3 {
  margin: 18px 0 0;
  font-size: 1.05rem;
}

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

.faq-list {
  display: grid;
  gap: 14px;
}

.faq-item {
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border);
}

.site-footer {
  padding-block: 20px 36px;
  color: var(--muted);
  font-size: 0.92rem;
}

.site-footer p {
  margin: 0;
}

@media (min-width: 680px) {
  .site-header,
  .site-footer,
  .page {
    width: calc(100% - 64px);
    max-width: 900px;
  }

  .site-header {
    padding-top: 28px;
  }

  .page {
    padding-top: 36px;
  }

  .home-page {
    gap: 36px;
  }

  .calculator {
    padding: 24px;
  }

  h1 {
    font-size: 4rem;
  }

  .calculator-hero h1 {
    font-size: 3.4rem;
  }

  .result-title {
    font-size: 2.1rem;
  }

  .content h2 {
    font-size: 2rem;
  }

  .form-grid {
    grid-template-columns: 1fr 1.25fr 1fr;
    align-items: end;
  }
}