body:has(> .not-found-page) { margin: 0; }
.not-found-page { color: #202020; background: #fff; min-height: 100svh; display: flex; flex-direction: column; font: 400 15px/1.9 "Noto Sans JP", sans-serif; }
.not-found-page, .not-found-page * { box-sizing: border-box; }
.not-found-page a { color: inherit; text-decoration: none; }
.not-found-page a:focus-visible { outline: 3px solid #007bff; outline-offset: 6px; }
.not-found-header { margin: 26px 40px 0; padding: 20px 36px; border: 1px solid #e5e5e5; border-radius: 18px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.not-found-header a { display: flex; }
.not-found-header img { width: 190px; height: auto; }
.not-found-header > span { font: 400 13px/1.5 "futura-pt", sans-serif; letter-spacing: .18em; }
.not-found-main { width: min(1120px, calc(100% - 80px)); margin: auto; padding: 72px 0 56px; display: grid; grid-template-columns: 1fr 1.2fr; gap: 60px; align-items: center; }
.not-found-visual { position: relative; text-align: center; isolation: isolate; }
.not-found-visual::before { content: ""; position: absolute; inset: -40px -20px; z-index: -1; background: radial-gradient(ellipse at 45% 60%, #00e6eb66, #0099ff20 45%, transparent 70%); }
.not-found-visual > span { display: block; font: 500 clamp(130px, 17vw, 230px)/1 "futura-pt", sans-serif; letter-spacing: -.04em; }
.not-found-visual p { margin: 20px 0 0; font: 400 16px/1.5 "futura-pt", sans-serif; letter-spacing: .3em; }
.not-found-label { margin: 0 0 20px; color: #006dc9; font-size: 14px; letter-spacing: .06em; }
.not-found-content h1 { margin: 0; font-size: clamp(30px, 3.4vw, 44px); font-weight: 600; line-height: 1.55; letter-spacing: .08em; }
.not-found-description { margin: 24px 0 32px; color: #555; font-size: 14px; line-height: 2; }
.not-found-home { display: flex; align-items: center; justify-content: space-between; gap: 24px; width: min(340px, 100%); min-height: 64px; padding: 16px 28px; border: 1px solid #202020; box-shadow: 5px 5px 0 #202020; font-weight: 500; transition: background-color .2s, color .2s; }
.not-found-home:hover { background: #202020; color: #fff; }
.not-found-home > span { font-size: 24px; font-weight: 400; }
.not-found-navigation { grid-column: 1 / -1; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); border-top: 1px solid #d8d8d8; border-bottom: 1px solid #d8d8d8; }
.not-found-navigation a { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 24px 28px; transition: background-color .2s; }
.not-found-navigation a + a { border-left: 1px solid #d8d8d8; }
.not-found-navigation a:hover { background: #effbff; }
.not-found-navigation small { display: block; font: 400 12px/1.5 "futura-pt", sans-serif; letter-spacing: .14em; color: #666; margin-bottom: 5px; }
.not-found-navigation a > span:last-child { font-size: 24px; }
.not-found-footer { padding: 24px 40px; border-top: 1px solid #eee; display: flex; justify-content: space-between; gap: 16px; font-size: 12px; color: #666; }
.not-found-footer a:hover { text-decoration: underline; }
@media (max-width: 760px) {
  .not-found-header { margin: 16px 20px 0; padding: 16px 20px; border-radius: 12px; }
  .not-found-header img { width: 150px; }
  .not-found-header > span { display: none; }
  .not-found-main { width: calc(100% - 48px); padding: 48px 0 36px; grid-template-columns: minmax(0, 1fr); gap: 40px; }
  .not-found-visual > span { font-size: 140px; }
  .not-found-visual p { margin-top: 8px; font-size: 12px; }
  .not-found-visual::before { inset: -25px 0; }
  .not-found-label { font-size: 12px; margin-bottom: 12px; }
  .not-found-content h1 { font-size: 32px; }
  .not-found-description { font-size: 13px; margin: 20px 0 28px; }
  .not-found-desktop-break { display: none; }
  .not-found-home { width: 100%; font-size: 14px; }
  .not-found-navigation { grid-template-columns: minmax(0, 1fr); }
  .not-found-navigation a { padding: 18px 8px; }
  .not-found-navigation a + a { border-left: 0; border-top: 1px solid #d8d8d8; }
  .not-found-footer { padding: 24px; flex-wrap: wrap; }
}
@media (prefers-reduced-motion: reduce) {
  .not-found-page a { transition: none; }
}