:root {
  --loader-size: 50vmin;
  --color-bg: #111827;
  --color-text-muted: #6b7280;
  --color-routes: #888888;
  --color-stops-fill: #94a3b8;
  --color-stops-stroke: #cbd5e1;
  --color-speed-0: #c0392b;
  --color-speed-5: #e67e22;
  --color-speed-15: #f1c40f;
  --color-speed-30: #27ae60;
  --color-speed-50: #1abc9c;
}

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

body {
  display: grid;
  grid-template-columns: 1fr auto;
  grid-template-rows: auto 1fr auto;
  grid-template-areas: "header header" "map    map" "status footer";
  width: 100vw;
  height: 100dvh;
  overflow: hidden;
  background: var(--color-bg);
}

header {
  grid-area: header;
  position: relative;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0 1.25rem;
  height: 3rem;
  background: #1a2233;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

#map {
  grid-area: map;
  position: relative;
  overflow: hidden;
  min-height: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.header-brand {
  font-family: monospace;
  font-size: 0.9rem;
  font-weight: bold;
  color: var(--color-stops-stroke);
  letter-spacing: 0.05em;
  white-space: nowrap;
  flex-shrink: 0;
}

#header-nav {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-left: auto;
}

.nav-btn {
  font-family: monospace;
  font-size: 0.78rem;
  color: var(--color-text-muted);
  background: transparent;
  border: 1px solid rgba(107, 114, 128, 0.35);
  border-radius: 4px;
  padding: 0.3rem 0.7rem;
  cursor: pointer;
  transition: color 0.15s ease, border-color 0.15s ease;
  white-space: nowrap;
}
.nav-btn:hover {
  color: var(--color-stops-fill);
  border-color: var(--color-stops-fill);
}
.nav-btn.active {
  color: var(--color-speed-30);
  border-color: var(--color-speed-30);
}

.nav-toggle-input {
  display: none;
}

.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 2rem;
  height: 2rem;
  cursor: pointer;
  margin-left: auto;
  flex-shrink: 0;
}
.hamburger span {
  display: block;
  height: 2px;
  background: var(--color-text-muted);
  border-radius: 2px;
  transition: transform 0.2s ease, opacity 0.2s ease;
  transform-origin: center;
}

.nav-toggle-input:checked ~ .hamburger span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle-input:checked ~ .hamburger span:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}

.nav-toggle-input:checked ~ .hamburger span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

@media (max-width: 600px) {
  .hamburger {
    display: flex;
  }
  #header-nav {
    display: none;
    position: absolute;
    top: 3rem;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    margin-left: 0;
    background: #1a2233;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    padding: 0.5rem 1rem;
  }
  #header-nav .nav-btn {
    text-align: left;
    padding: 0.6rem 0.5rem;
    border: none;
    border-radius: 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.04);
  }
  #header-nav .nav-btn:last-child {
    border-bottom: none;
  }
  .nav-toggle-input:checked ~ .hamburger ~ #header-nav {
    display: flex;
  }
}
#footer-links {
  grid-area: footer;
  padding: 0.5rem 1rem;
  font-size: 0.8rem;
  font-family: monospace;
  display: flex;
  gap: 1rem;
}
#footer-links a {
  color: var(--color-text-muted);
  text-decoration: none;
}
#footer-links a:hover {
  color: var(--color-stops-fill);
}

#colorbar {
  grid-area: map;
  align-self: end;
  justify-self: end;
  margin: 0 1rem 1rem 0;
  width: 180px;
  height: 60px;
  padding: 0.5rem;
  pointer-events: none;
  z-index: 10;
  background: rgba(17, 24, 39, 0.75);
  border-radius: 6px;
}
#colorbar svg {
  display: block;
  overflow: visible;
}

#status {
  grid-area: status;
  padding: 0.5rem 1rem;
  font-size: 0.8rem;
  font-family: monospace;
  color: var(--color-text-muted);
}

.loader {
  width: var(--loader-size);
  height: var(--loader-size);
  display: inline-block;
  position: relative;
}
.loader::before, .loader::after {
  content: "";
  box-sizing: border-box;
  width: var(--loader-size);
  height: var(--loader-size);
  border-radius: 50%;
  border: 4px solid #fff;
  position: absolute;
  left: 0;
  top: 0;
  transform-origin: center;
  backface-visibility: hidden;
  will-change: transform, opacity;
  animation: animloader 2s linear infinite backwards;
}
.loader::after {
  animation-delay: 1s;
}

@keyframes animloader {
  0% {
    transform: scale(0);
    opacity: 1;
  }
  100% {
    transform: scale(1);
    opacity: 0;
  }
}