:root {
  --primary: #1ccbff;
  --primary-strong: #138eb2;
  --on-primary: #04223a;
  --bg: #051b34;
  --card: #0a2645;
  --card-hover: #0e3159;
  --border: rgba(28, 203, 255, 0.18);
  --text: #ffffff;
  --muted: #a9bdd3;
  /* the logo file is drawn for light backgrounds */
  --logo-filter: invert(100%) hue-rotate(180deg) saturate(10);
}

:root.light-mode {
  --primary: #1565c0;
  --primary-strong: #0e4686;
  --on-primary: #ffffff;
  --bg: #f4f7fb;
  --card: #ffffff;
  --card-hover: #eef4fc;
  --border: rgba(21, 101, 192, 0.18);
  --text: #0b1b2e;
  --muted: #4a5d73;
  --logo-filter: none;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--text);
  font-family: 'Nunito', system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}

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

/* --- header --------------------------------------------------------------- */

.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 20px 24px 0;
}

.logo {
  display: block;
  height: 64px;
  width: auto;
  filter: var(--logo-filter);
}

#theme-toggle {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: transparent;
  color: var(--text);
  cursor: pointer;
}

#theme-toggle svg {
  width: 20px;
  height: 20px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
}

#theme-toggle .icon-moon,
.light-mode #theme-toggle .icon-sun {
  display: none;
}

.light-mode #theme-toggle .icon-moon {
  display: block;
}

/* --- intro and network cards ---------------------------------------------- */

main {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 24px;
}

.intro {
  max-width: 760px;
  margin: 24px auto 40px;
  text-align: center;
}

.intro h1 {
  margin: 0 0 12px;
  font-size: clamp(1.6rem, 3.2vw, 2.4rem);
  font-weight: 800;
  line-height: 1.2;
}

.intro p {
  margin: 0;
  color: var(--muted);
  font-size: 1.1rem;
  line-height: 1.5;
}

.chains {
  display: grid;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  gap: 16px;
}

.chain {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 20px 12px 16px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--card);
  transition: background 0.15s, transform 0.15s;
}

.chain:hover {
  background: var(--card-hover);
  transform: translateY(-2px);
}

.chain img {
  width: 72px;
  height: 72px;
  object-fit: contain;
}

.chain h2 {
  margin: 12px 0 14px;
  font-size: 1.05rem;
  font-weight: 700;
  text-align: center;
}

.links {
  display: flex;
  flex-direction: column;
  gap: 8px;
  width: 100%;
  margin-top: auto;
}

.button {
  display: block;
  padding: 8px 6px;
  border: 1px solid var(--primary);
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 700;
  text-align: center;
  text-decoration: none;
  white-space: nowrap;
  transition: background 0.15s, color 0.15s;
}

.button.primary {
  background: var(--primary);
  color: var(--on-primary);
}

.button.primary:hover {
  background: var(--primary-strong);
  border-color: var(--primary-strong);
  color: #ffffff;
}

.button.secondary {
  color: var(--primary);
}

.button.secondary:hover {
  background: var(--primary);
  color: var(--on-primary);
}

/* Jungle4: the testnet everyone builds on, in its own colours */
.button.jungle {
  --jungle-teal: #00cbab;
  --jungle-green: #016c2c;
  --button-bg: var(--card);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  border: 1.5px solid transparent;
  background:
    linear-gradient(var(--button-bg), var(--button-bg)) padding-box,
    linear-gradient(135deg, var(--jungle-teal), var(--jungle-green)) border-box;
  color: var(--jungle-teal);
}

.chain:hover .button.jungle {
  --button-bg: var(--card-hover);
}

.light-mode .button.jungle {
  color: #017a52;
}

.button.jungle img {
  width: 20px;
  height: 20px;
  padding: 2px;
  border-radius: 50%;
  background: #ffffff;
  object-fit: contain;
  transform-origin: 50% 90%;
}

.button.jungle:hover,
.light-mode .button.jungle:hover {
  background:
    linear-gradient(135deg, var(--jungle-teal), var(--jungle-green)) padding-box,
    linear-gradient(135deg, var(--jungle-teal), var(--jungle-green)) border-box;
  color: #ffffff;
  box-shadow: 0 0 14px rgba(0, 203, 171, 0.45);
}

.button.jungle:hover img {
  animation: jungle-sway 1.2s ease-in-out infinite;
}

@keyframes jungle-sway {
  0%, 100% { transform: rotate(0deg); }
  25% { transform: rotate(-12deg); }
  75% { transform: rotate(12deg); }
}

@media (prefers-reduced-motion: reduce) {
  .button.jungle:hover img {
    animation: none;
  }
}

.button:focus-visible,
#theme-toggle:focus-visible,
.social a:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* --- footer --------------------------------------------------------------- */

.bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 12px 28px;
  margin-top: 32px;
  padding: 20px 24px 24px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.95rem;
}

.credit {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  text-decoration: none;
}

.eosphere-logo {
  width: 28px;
  height: 28px;
}

.eosphere-wordmark {
  height: 20px;
  width: auto;
}

.wordmark-on-light,
.light-mode .wordmark-on-dark {
  display: none;
}

.light-mode .wordmark-on-light {
  display: inline;
}

.social {
  display: flex;
  gap: 16px;
}

.social a {
  display: grid;
  place-items: center;
  color: var(--muted);
}

.social a:hover {
  color: var(--primary);
}

.social svg {
  width: 22px;
  height: 22px;
}

.social .fill {
  fill: currentColor;
}

.origin {
  margin: 0;
  font-size: 0.85rem;
}

.origin a {
  color: var(--muted);
}

/* --- smaller screens ------------------------------------------------------ */

@media (max-width: 1100px) {
  .chains {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (max-width: 720px) {
  .top {
    padding: 16px 16px 0;
  }

  .logo {
    height: 48px;
  }

  main {
    padding: 0 16px;
  }

  .intro {
    margin: 24px auto;
  }

  .intro p {
    font-size: 1rem;
  }

  .chains {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
  }

  .chain img {
    width: 56px;
    height: 56px;
  }

  .bottom {
    flex-direction: column;
    gap: 12px;
  }

  .credit {
    flex-wrap: wrap;
    justify-content: center;
  }

  .credit span {
    flex-basis: 100%;
    text-align: center;
  }
}