:root {
  --color-primary: #2563EB;
  --color-primary-dark: #1D4ED8;
  --color-success: #16A34A;
  --color-bg: #FFFFFF;
  --color-surface: #F9FAFB;
  --color-border: #E5E7EB;
  --color-text: #111827;
  --color-text-secondary: #6B7280;

  --max-width: 960px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.6;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* Hero */
.hero {
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 64px 0;
  text-align: center;
}

.hero h1 {
  margin: 0;
  font-size: 2.5rem;
  color: var(--color-primary-dark);
}

.hero .tagline {
  margin: 8px 0 24px;
  font-size: 1.25rem;
  color: var(--color-text-secondary);
}

.hero .intro {
  max-width: 640px;
  margin: 0 auto;
  font-size: 1rem;
}

/* Sections */
main section {
  padding: 48px 0;
}

main h2 {
  margin-top: 0;
  margin-bottom: 24px;
  font-size: 1.75rem;
}

/* Features */
.feature-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.feature-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 20px;
  transition: border-color 0.15s ease;
}

.feature-card:hover {
  border-color: var(--color-primary);
}

.feature-card h3 {
  margin: 0 0 8px;
  font-size: 1.125rem;
  color: var(--color-primary-dark);
}

.feature-card p {
  margin: 0;
  color: var(--color-text-secondary);
}

/* Technology */
.tech-list {
  margin: 0;
  display: grid;
  gap: 12px;
}

.tech-item {
  padding: 12px 16px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
}

.tech-item dt {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.tech-item dd {
  margin: 4px 0 0;
}

/* Status */
.status-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 12px;
}

.status-list li {
  display: flex;
  align-items: center;
  gap: 12px;
}

.status-dot {
  display: inline-block;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

.status-done {
  background-color: var(--color-success);
}

.status-pending {
  background-color: var(--color-text-secondary);
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 24px 0;
}

.site-footer p {
  margin: 0;
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  text-align: center;
}

/* Responsive */
@media (min-width: 640px) {
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .tech-item {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 16px;
  }

  .tech-item dd {
    margin: 0;
  }
}

@media (min-width: 960px) {
  .feature-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}