*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: #f5f4f0;
  color: #2c2c2c;
  line-height: 1.6;
  padding: 2rem 1rem;
}

.container {
  max-width: 720px;
  margin: 0 auto;
}

header {
  text-align: center;
  padding: 3rem 0 2rem;
}

header h1 {
  font-size: 2.5rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  margin-bottom: 0.75rem;
}

.tagline {
  font-size: 1.1rem;
  color: #5a5a5a;
  max-width: 480px;
  margin: 0 auto;
}

main {
  padding: 2rem 0;
}

main h2 {
  font-size: 1.25rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #888;
  margin-bottom: 1.25rem;
}

.app-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
}

.card {
  display: block;
  background: #ffffff;
  border: 1px solid #e4e2dc;
  border-radius: 12px;
  padding: 1.5rem;
  text-decoration: none;
  color: inherit;
  transition: box-shadow 0.15s ease, transform 0.15s ease;
}

.card:hover {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
  transform: translateY(-2px);
}

.card h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: #1a1a1a;
}

.card p {
  font-size: 0.95rem;
  color: #5a5a5a;
}

.back-link {
  display: inline-block;
  margin-bottom: 2rem;
  font-size: 0.9rem;
  color: #5a5a5a;
  text-decoration: none;
}

.back-link:hover {
  color: #1a1a1a;
  text-decoration: underline;
}

.app-page header {
  text-align: left;
  padding: 2rem 0 1.5rem;
}

.app-page header h1 {
  font-size: 2rem;
}

.app-page .description {
  font-size: 1.1rem;
  color: #4a4a4a;
  max-width: 540px;
}

.dev-page main {
  padding-top: 1rem;
}

.warning-banner {
  border: 1px solid #f5d36b;
  background: #fff5d6;
  color: #6b4f00;
  border-radius: 10px;
  padding: 0.85rem 1rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
}

.dev-tool-section {
  background: #ffffff;
  border: 1px solid #e4e2dc;
  border-radius: 12px;
  padding: 1.25rem;
  margin-bottom: 1.25rem;
}

.dev-tool-section h2 {
  margin-bottom: 0.85rem;
}

.dev-links-list {
  list-style: none;
  display: grid;
  gap: 1rem;
}

.dev-links-list a {
  color: #2d4f8b;
  font-weight: 600;
  text-decoration: none;
}

.dev-links-list a:hover {
  text-decoration: underline;
}

.dev-links-list p {
  margin-top: 0.25rem;
  color: #5a5a5a;
  font-size: 0.95rem;
}

.env-info {
  display: grid;
  gap: 0.75rem;
}

.env-info div {
  background: #f8f7f4;
  border: 1px solid #ece9e2;
  border-radius: 8px;
  padding: 0.75rem;
}

.env-info dt {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: #7b7b7b;
  margin-bottom: 0.2rem;
}

.env-info dd {
  font-size: 0.95rem;
  color: #2d2d2d;
  word-break: break-word;
}

.info-list {
  margin: 1rem 0 1.5rem 1.25rem;
  color: #4a4a4a;
  font-size: 0.95rem;
  line-height: 1.8;
}

code {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 0.875em;
  background: #eeecea;
  padding: 0.15em 0.4em;
  border-radius: 4px;
}

footer {
  text-align: center;
  padding: 3rem 0 1rem;
  font-size: 0.85rem;
  color: #aaa;
}