:root {
  --bg-primary: #ffffff;
  --bg-subtle: #f4f4f5;
  --text-primary: #0a0a0a;
  --text-secondary: #4b5563;
  --border-subtle: #e4e4e7;
  --black-solid: #000000;
  --black-hover: #1f2937;
  --white-solid: #ffffff;
  --radius-full: 9999px;
  --font-en: 'Outfit', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-jp: 'Noto Sans JP', -apple-system, BlinkMacSystemFont, 'Hiragino Kaku Gothic ProN', sans-serif;
}

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

html {
  color-scheme: light;
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-jp);
  line-height: 1.7;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

.btn-primary {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  background: var(--black-solid);
  color: var(--white-solid);
  font-family: var(--font-jp);
  font-weight: 700;
  font-size: 0.98rem;
  padding: 0.9rem 2.25rem;
  min-height: 50px;
  border-radius: var(--radius-full);
  border: 1px solid var(--black-solid);
  cursor: pointer;
  text-decoration: none;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.12);
  transition: background-color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease, transform 0.16s ease;
  -webkit-tap-highlight-color: transparent;
}

.btn-primary:hover {
  background: var(--black-hover);
  border-color: var(--black-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.18);
}

.btn-primary:active {
  transform: translateY(0);
}

.error-page-container {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 7rem 1.25rem 4rem;
  width: 100%;
}

.error-hero {
  max-width: 680px;
  width: 100%;
  margin: 0 auto;
  text-align: center;
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.error-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.9rem;
  background: var(--bg-subtle);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-full);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-secondary);
  font-family: var(--font-en);
  margin-bottom: 1.5rem;
}

.error-code {
  font-family: var(--font-en);
  font-size: clamp(5.5rem, 22vw, 10.5rem);
  font-weight: 900;
  line-height: 0.9;
  letter-spacing: -0.06em;
  color: var(--text-primary);
  margin-bottom: 1.25rem;
  user-select: none;
  background: linear-gradient(180deg, #000000 0%, #333333 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.error-heading {
  font-size: clamp(1.25rem, 4.2vw, 2rem);
  font-weight: 800;
  letter-spacing: -0.025em;
  line-height: 1.4;
  color: var(--text-primary);
  margin-bottom: 1rem;
  word-break: auto-phrase;
  overflow-wrap: break-word;
}

.error-desc {
  max-width: 520px;
  margin: 0 auto 2.25rem;
  color: var(--text-secondary);
  font-size: clamp(0.9rem, 2.6vw, 1.02rem);
  line-height: 1.75;
  word-break: auto-phrase;
  overflow-wrap: break-word;
}

.error-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.85rem;
  flex-wrap: wrap;
  width: 100%;
}

.error-actions .btn-primary {
  width: 100%;
  max-width: 280px;
  min-height: 48px;
}

@media (max-width: 768px) {
  .desktop-br {
    display: none !important;
  }
}