:root {
  --bg: #ffffff;
  --fg: #0a0a0a;
  --muted: #525252;
  --accent: #0a0a0a;
  --card: #ffffff;
  --radius: 16px;
  --hairline: rgba(0, 0, 0, 0.08);
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-hover: 0 10px 40px rgba(0, 0, 0, 0.08);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Inter", "Pretendard", "Noto Sans KR", system-ui, -apple-system, Segoe UI, sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.55;
  font-size: 1rem;
  letter-spacing: -0.01em;
}

a {
  color: var(--accent);
}

a:focus-visible {
  outline: 2px solid var(--fg);
  outline-offset: 3px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.site-header {
  padding: 3rem 1.5rem 2.75rem;
  text-align: center;
  border-bottom: 1px solid var(--hairline);
  background: var(--bg);
}

.header-brand {
  display: block;
  margin: 0 auto;
  max-width: min(360px, 88vw);
  width: 100%;
  height: auto;
}

.site-header .tagline {
  margin: 1.75rem 0 0;
  color: var(--muted);
  font-size: 0.9375rem;
  font-weight: 400;
  letter-spacing: -0.02em;
}

main {
  max-width: 960px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
}

.section-title {
  margin: 0 0 1.5rem;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--muted);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

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

.app-card {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  text-decoration: none;
  color: inherit;
  background: var(--card);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
  border: 1px solid var(--hairline);
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

.app-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

.app-card:focus-visible {
  outline: 2px solid var(--fg);
  outline-offset: 2px;
}

.app-card__row {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}

.app-card__icon {
  width: 72px;
  height: 72px;
  flex-shrink: 0;
  border-radius: 16px;
  object-fit: cover;
  background: #fafafa;
  border: 1px solid var(--hairline);
}

.app-card__body {
  flex: 1;
  min-width: 0;
}

.app-card__name {
  margin: 0 0 0.35rem;
  font-size: 1.0625rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.app-card__desc {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--muted);
}

.app-card__cta {
  margin-top: 1.25rem;
  padding-top: 1rem;
  border-top: 1px solid var(--hairline);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--fg);
  letter-spacing: 0.02em;
}

.error-banner {
  display: none;
  margin-bottom: 1.5rem;
  padding: 1rem 1.25rem;
  border-radius: 12px;
  background: #fafafa;
  color: #171717;
  font-size: 0.9375rem;
  border: 1px solid var(--hairline);
}

.error-banner[data-visible="true"] {
  display: block;
}

.site-footer {
  text-align: center;
  padding: 2rem 1.5rem;
  color: var(--muted);
  font-size: 0.8125rem;
  border-top: 1px solid var(--hairline);
}