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

:root {
  font-size: 62.5%;
  color-scheme: light;
}

html {
  width: 100%;
  min-height: 100%;
  min-height: 100dvh;
  background: #fff;
}

body {
  font-size: 16px;
  width: 100%;
  min-height: 100%;
  min-height: 100dvh;
  overflow: hidden;
  background: #fff;
  font-family: 'Roboto Mono', 'Pretendard Variable', 'Pretendard', sans-serif;
}

/* ── Safe Area ── */
.sa-bg {
  position: fixed;
  left: 0; right: 0;
  background: #fff;
  z-index: 999999;
  pointer-events: none;
}
.sa-bg-top {
  top: 0;
  height: constant(safe-area-inset-top);
  height: env(safe-area-inset-top, 0px);
}
.sa-bg-bottom {
  bottom: 0;
  height: constant(safe-area-inset-bottom);
  height: env(safe-area-inset-bottom, 0px);
}

/* ── Navigation ── */
#main-nav {
  position: fixed;
  top: max(12px, constant(safe-area-inset-top));
  top: max(12px, env(safe-area-inset-top, 12px));
  left: max(14px, constant(safe-area-inset-left));
  left: max(14px, env(safe-area-inset-left, 14px));
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 1px;
  mix-blend-mode: difference;
}
.nav-link {
  font-family: 'helvetica-neue-lt-pro', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 20px;
  font-weight: 400;
  letter-spacing: 0.00em;
  line-height: 1.25;
  color: #808080;
  text-decoration: none;
  display: block;
  cursor: pointer;
  user-select: none; -webkit-user-select: none;
  -webkit-tap-highlight-color: transparent;
  transition: color 0.3s ease;
}
.nav-link.active { color: #FFFFFF; }
@media (max-width: 768px) {
  .nav-link { font-size: 22px; font-weight: 500; }
  #main-nav { gap: 3px; }
}

/* ── Logo ── */
#logo-btn {
  position: fixed;
  bottom: max(20px, constant(safe-area-inset-bottom));
  bottom: max(20px, env(safe-area-inset-bottom, 20px));
  left: 50%;
  transform: translateX(-50%);
  z-index: 9999;
  cursor: pointer;
  user-select: none; -webkit-user-select: none;
  -webkit-tap-highlight-color: transparent;
  display: block;
  text-decoration: none;
}
#logo-btn img { display: block; width: clamp(210px, 55vw, 270px); height: auto; pointer-events: none; }
@media (pointer: fine) {
  #logo-btn { bottom: 32px; }
}
@media (max-width: 768px) {
  #logo-btn img { width: clamp(245px, 68vw, 310px); }
}