:root {
  color-scheme: dark;
  --bg: #01050b;
  --panel: rgba(2, 12, 24, 0.82);
  --panel-2: rgba(4, 18, 34, 0.78);
  --blue: #1fc7ff;
  --blue-soft: rgba(31, 199, 255, 0.18);
  --blue-line: rgba(31, 199, 255, 0.68);
  --text: #effbff;
  --muted: #7cc9e8;
  --glow: 0 0 18px rgba(31, 199, 255, 0.45), 0 0 44px rgba(31, 199, 255, 0.16);
}

* {
  box-sizing: border-box;
}

body {
  min-height: 100vh;
  margin: 0;
  background:
    linear-gradient(rgba(1, 5, 11, 0.6), rgba(1, 5, 11, 0.94)),
    url("https://images.unsplash.com/photo-1519501025264-65ba15a82390?auto=format&fit=crop&w=1400&q=80")
      center / cover fixed,
    var(--bg);
  color: var(--text);
  font-family: "Share Tech Mono", monospace;
  letter-spacing: 0;
}

button,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

.signal-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 20px;
}

.signal-window {
  width: min(760px, 100%);
  border: 1px solid var(--blue-line);
  background: var(--panel);
  box-shadow: var(--glow), inset 0 0 38px rgba(31, 199, 255, 0.08);
  backdrop-filter: blur(14px);
  clip-path: polygon(14px 0, calc(100% - 14px) 0, 100% 14px, 100% calc(100% - 14px), calc(100% - 14px) 100%, 14px 100%, 0 calc(100% - 14px), 0 14px);
  padding: 10px;
}

.window-bar,
.signal-card,
.command-line,
.bottom-nav {
  border: 1px solid var(--blue-line);
  background: rgba(0, 10, 22, 0.7);
  box-shadow: inset 0 0 20px rgba(31, 199, 255, 0.09);
}

.window-bar {
  min-height: 64px;
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr) auto 48px;
  gap: 10px;
  align-items: center;
  padding: 8px 12px;
  clip-path: polygon(10px 0, 100% 0, 100% calc(100% - 10px), calc(100% - 10px) 100%, 0 100%, 0 10px);
}

h1 {
  margin: 0;
  color: var(--blue);
  font-size: clamp(1.15rem, 4vw, 2rem);
  line-height: 1;
  text-transform: uppercase;
  text-shadow: 0 0 14px rgba(31, 199, 255, 0.72);
}

.window-bar strong {
  color: var(--blue);
  font-size: clamp(0.95rem, 3vw, 1.5rem);
  text-transform: uppercase;
}

.round-action,
.send-button,
.heart-button {
  border: 1px solid var(--blue-line);
  color: var(--text);
  background: rgba(255, 255, 255, 0.04);
  box-shadow: 0 0 16px rgba(31, 199, 255, 0.22);
}

.round-action,
.send-button {
  width: 44px;
  height: 44px;
  border-radius: 50%;
}

.feed {
  display: grid;
  gap: 12px;
  margin: 12px 0;
}

.signal-card {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr) 54px;
  gap: 14px;
  align-items: center;
  min-height: 130px;
  padding: 14px;
  clip-path: polygon(14px 0, 100% 0, 100% calc(100% - 14px), calc(100% - 14px) 100%, 0 100%, 0 14px);
}

.avatar {
  width: 72px;
  height: 72px;
  display: grid;
  place-items: center;
  border: 1px solid var(--blue);
  border-radius: 50%;
  color: var(--blue);
  font-size: 2rem;
  text-shadow: 0 0 12px var(--blue);
  background: radial-gradient(circle at 35% 30%, rgba(31, 199, 255, 0.28), rgba(1, 5, 11, 0.88) 64%);
}

.signal-head {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  color: var(--blue);
  text-transform: uppercase;
}

.signal-head strong {
  color: var(--text);
  font-size: clamp(1.35rem, 4vw, 2rem);
}

.signal-head span {
  flex: 0 0 auto;
  font-size: clamp(0.9rem, 3vw, 1.3rem);
}

.signal-card p {
  margin: 10px 0 0;
  color: var(--text);
  font-size: clamp(1.08rem, 3.5vw, 1.65rem);
  line-height: 1.32;
}

.heart-button {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  color: var(--blue);
  font-size: 2rem;
}

.heart-button.liked {
  color: var(--text);
  background: var(--blue-soft);
}

.divider {
  display: grid;
  place-items: center;
  height: 40px;
  margin-bottom: 12px;
  border: 1px solid var(--blue-line);
  color: var(--blue);
  font-size: 1.5rem;
  letter-spacing: 0.22em;
  background: rgba(0, 10, 22, 0.6);
}

.command-line {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 50px;
  gap: 10px;
  align-items: center;
  min-height: 74px;
  padding: 10px 12px;
  margin-bottom: 12px;
}

input {
  width: 100%;
  min-height: 52px;
  border: 0;
  outline: 0;
  color: var(--text);
  background: transparent;
  font-size: clamp(1.05rem, 4vw, 1.55rem);
}

input::placeholder {
  color: rgba(124, 201, 232, 0.68);
}

.bottom-nav {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 10px;
  padding: 10px;
}

.nav-button {
  min-width: 0;
  min-height: 98px;
  display: grid;
  place-items: center;
  gap: 5px;
  border: 1px solid var(--blue-line);
  color: var(--blue);
  background: rgba(31, 199, 255, 0.06);
  text-transform: uppercase;
  font-size: clamp(0.62rem, 2vw, 0.95rem);
}

.nav-button.active,
.nav-button:hover {
  color: var(--text);
  background: rgba(31, 199, 255, 0.16);
  box-shadow: inset 0 0 18px rgba(31, 199, 255, 0.16);
}

.nav-icon {
  font-size: clamp(1.6rem, 6vw, 2.5rem);
  line-height: 1;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 620px) {
  .signal-shell {
    padding: 10px;
    place-items: start center;
  }

  .window-bar {
    grid-template-columns: 40px minmax(0, 1fr) auto 40px;
    gap: 6px;
    padding: 8px;
  }

  .round-action,
  .send-button {
    width: 38px;
    height: 38px;
  }

  .signal-card {
    grid-template-columns: 58px minmax(0, 1fr) 44px;
    min-height: 116px;
    gap: 10px;
    padding: 12px;
  }

  .avatar {
    width: 58px;
    height: 58px;
    font-size: 1.5rem;
  }

  .heart-button {
    width: 40px;
    height: 40px;
    font-size: 1.55rem;
  }

  .bottom-nav {
    gap: 6px;
    padding: 8px;
  }

  .nav-button {
    min-height: 78px;
    padding: 5px 2px;
  }
}