:root {
  color-scheme: light;
  --bg: #f7f8fa;
  --surface: #ffffff;
  --surface-muted: #f1f4f8;
  --text: #1f2328;
  --muted: #5f6b7a;
  --border: #d8dee8;
  --border-soft: #e7ebf1;
  --accent: #0969da;
  --accent-strong: #0758b7;
  --success: #1a7f37;
  --shadow: 0 20px 50px rgba(31, 35, 40, 0.08);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  background: var(--bg);
}

body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-size: 16px;
  line-height: 1.6;
}

a {
  color: inherit;
}

.site-header,
main,
.footer {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

.site-header {
  padding: 28px 0 36px;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 72px;
}

.brand,
.profile-link {
  text-decoration: none;
}

.brand {
  font-weight: 700;
  letter-spacing: 0;
}

.profile-link {
  color: var(--muted);
  font-size: 0.95rem;
}

.profile-link:hover,
.footer a:hover {
  color: var(--accent);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(300px, 0.85fr);
  gap: 56px;
  align-items: center;
  min-height: 520px;
}

.hero-content {
  max-width: 720px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--success);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

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

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.15;
}

h1 {
  max-width: 780px;
  font-size: clamp(2.4rem, 7vw, 4.8rem);
  letter-spacing: 0;
}

.subtitle {
  max-width: 620px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: clamp(1.08rem, 2vw, 1.35rem);
}

.button-group {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 18px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-weight: 700;
  text-decoration: none;
}

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

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

.button-secondary {
  color: var(--text);
  background: var(--surface);
  border-color: var(--border);
}

.button-secondary:hover {
  border-color: #b8c2d2;
}

.workflow-panel {
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.panel-header {
  display: flex;
  gap: 7px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--border-soft);
  background: var(--surface-muted);
}

.panel-header span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #c2cad6;
}

.panel-body {
  display: grid;
  gap: 14px;
  padding: 22px;
}

.step {
  display: grid;
  grid-template-columns: 36px 1fr;
  gap: 12px;
  align-items: center;
  padding: 14px;
  border: 1px solid var(--border-soft);
  border-radius: 8px;
  background: #fbfcfe;
}

.step span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  color: var(--accent);
  background: #eaf3ff;
  font-weight: 800;
}

.step p {
  margin: 0;
  color: var(--text);
  font-weight: 700;
}

.step.is-active {
  border-color: #b7d7ff;
  background: #f3f8ff;
}

.impact-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  padding: 0 0 72px;
}

.impact-card {
  min-height: 190px;
  padding: 24px;
  border: 1px solid var(--border-soft);
  border-radius: 8px;
  background: var(--surface);
}

.impact-card span {
  color: var(--success);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.08em;
}

.impact-card h2 {
  margin-top: 18px;
  font-size: 1.28rem;
}

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

.sheet-preview {
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.preview-toolbar {
  display: flex;
  gap: 7px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--border-soft);
  background: var(--surface-muted);
}

.preview-toolbar span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #c2cad6;
}

.preview-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  min-width: 0;
  padding: 18px;
}

.preview-cell {
  min-height: 48px;
  padding: 12px;
  border-right: 1px solid var(--border-soft);
  border-bottom: 1px solid var(--border-soft);
  color: var(--muted);
  font-size: 0.92rem;
}

.preview-cell:nth-child(3n) {
  border-right: 0;
}

.preview-cell:nth-last-child(-n + 3) {
  border-bottom: 0;
}

.preview-head {
  color: var(--text);
  background: #f6f8fa;
  font-weight: 700;
}

.section {
  padding: 72px 0;
  border-top: 1px solid var(--border-soft);
}

.split {
  display: grid;
  grid-template-columns: minmax(220px, 0.82fr) minmax(0, 1.18fr);
  gap: 48px;
}

.section-heading {
  max-width: 680px;
  margin-bottom: 28px;
}

h2 {
  font-size: clamp(1.7rem, 4vw, 2.4rem);
  letter-spacing: 0;
}

.section-copy {
  max-width: 800px;
}

.section-copy p + p {
  margin-top: 18px;
}

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

.benefit-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  overflow: hidden;
  border: 1px solid var(--border-soft);
  border-radius: 8px;
  background: var(--border-soft);
}

.benefit-list article {
  min-height: 170px;
  padding: 24px;
  background: var(--surface);
}

.benefit-list h3 {
  font-size: 1.08rem;
}

.benefit-list p {
  margin-top: 12px;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.card {
  min-height: 166px;
  padding: 24px;
  border: 1px solid var(--border-soft);
  border-radius: 8px;
  background: var(--surface);
}

.card h3 {
  font-size: 1.05rem;
  letter-spacing: 0;
}

.card p {
  margin-top: 12px;
  font-size: 0.96rem;
}

.flow {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.flow li {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 84px;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  text-align: center;
  font-weight: 700;
}

.flow li:not(:last-child)::after {
  content: "→";
  position: absolute;
  right: -15px;
  z-index: 1;
  color: var(--muted);
  font-weight: 700;
}

.privacy {
  padding: 36px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
}

.privacy .section-heading,
.note .section-heading {
  margin-bottom: 18px;
}

.demo-section .preview-grid {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.demo-section .preview-cell:nth-child(3n) {
  border-right: 1px solid var(--border-soft);
}

.demo-section .preview-cell:nth-last-child(-n + 3) {
  border-bottom: 1px solid var(--border-soft);
}

.demo-section .preview-cell:nth-child(5n) {
  border-right: 0;
}

.demo-section .preview-cell:nth-last-child(-n + 5) {
  border-bottom: 0;
}

.note {
  padding: 36px;
  border: 1px solid #b7d7ff;
  border-radius: 8px;
  background: #f3f8ff;
}

.pills {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.pills li {
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--text);
  font-size: 0.95rem;
  font-weight: 700;
}

.footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 36px 0 48px;
  color: var(--muted);
  border-top: 1px solid var(--border-soft);
}

.footer p {
  margin: 0;
}

.footer a {
  font-weight: 700;
  text-decoration: none;
}

@media (max-width: 860px) {
  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
  }

  .nav {
    margin-bottom: 52px;
  }

  .impact-grid,
  .split {
    grid-template-columns: 1fr;
  }

  .impact-grid {
    padding-bottom: 56px;
  }

  .card-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .flow li:not(:last-child)::after {
    content: "↓";
    right: auto;
    bottom: -19px;
  }

  .demo-section .preview-grid {
    grid-template-columns: 1fr;
  }

  .demo-section .preview-cell,
  .demo-section .preview-cell:nth-child(3n),
  .demo-section .preview-cell:nth-child(5n),
  .demo-section .preview-cell:nth-last-child(-n + 3),
  .demo-section .preview-cell:nth-last-child(-n + 5) {
    border-right: 0;
    border-bottom: 1px solid var(--border-soft);
  }

  .demo-section .preview-cell:last-child {
    border-bottom: 0;
  }
}

@media (max-width: 620px) {
  .site-header,
  main,
  .footer {
    width: min(100% - 28px, 1120px);
  }

  .site-header {
    padding-top: 20px;
  }

  .nav,
  .footer {
    align-items: flex-start;
    flex-direction: column;
  }

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

  .impact-card,
  .benefit-list article {
    min-height: auto;
  }

  .benefit-list {
    grid-template-columns: 1fr;
  }

  .button {
    width: 100%;
  }

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

  .preview-cell,
  .preview-cell:nth-child(3n),
  .preview-cell:nth-last-child(-n + 3) {
    border-right: 0;
    border-bottom: 1px solid var(--border-soft);
  }

  .preview-cell:last-child {
    border-bottom: 0;
  }

  .section {
    padding: 56px 0;
  }

  .privacy {
    padding: 24px;
  }
}