:root {
  color-scheme: dark;
  --ink: #050707;
  --paper: #edf6f2;
  --muted: rgba(237, 246, 242, 0.62);
  --line: rgba(238, 248, 244, 0.14);
  --panel: rgba(8, 14, 14, 0.58);
  --aqua: #83f0ea;
  --coral: #ff9b8e;
  --lime: #d7ff7c;
  --warm: #f6e1c3;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-width: 320px;
  background: var(--ink);
  color: var(--paper);
  font-family:
    Inter, "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, BlinkMacSystemFont,
    "Segoe UI", sans-serif;
  letter-spacing: 0;
}

button,
input,
textarea {
  font: inherit;
}

.receiver {
  --tone: var(--aqua);
  --tone-soft: rgba(131, 240, 234, 0.24);
  isolation: isolate;
  position: relative;
  display: grid;
  min-height: 100svh;
  overflow: hidden;
  padding: clamp(20px, 3vw, 38px);
  grid-template-rows: auto 1fr auto auto;
  background:
    linear-gradient(110deg, rgba(3, 8, 8, 0.98), rgba(3, 7, 7, 0.46) 40%, rgba(3, 7, 7, 0.92)),
    #030505;
}

.receiver::before,
.receiver::after {
  content: "";
  inset: 0;
  position: absolute;
  pointer-events: none;
}

.receiver::before {
  z-index: -1;
  opacity: 0.24;
  background:
    radial-gradient(circle at 58% 44%, var(--tone-soft) 0 12%, transparent 34%),
    linear-gradient(120deg, transparent 18%, var(--tone-soft) 52%, transparent 78%);
  mix-blend-mode: screen;
  transition: opacity 760ms ease, filter 760ms ease;
}

.receiver::after {
  z-index: 2;
  opacity: 0;
  background:
    radial-gradient(circle at 58% 44%, rgba(255, 255, 255, 0.34), var(--tone-soft) 18%, transparent 42%),
    linear-gradient(100deg, transparent 28%, rgba(255, 255, 255, 0.18), transparent 58%);
}

.receiver.is-receiving::before {
  opacity: 0.72;
}

.receiver.has-signal::before {
  opacity: 0.62;
  filter: saturate(1.4);
}

.receiver.is-receiving::after {
  animation: signal-sweep 1100ms ease-out;
}

.receiver[data-tone="coral"] {
  --tone: var(--coral);
  --tone-soft: rgba(255, 155, 142, 0.26);
}

.receiver[data-tone="lime"] {
  --tone: var(--lime);
  --tone-soft: rgba(215, 255, 124, 0.22);
}

.receiver[data-tone="warm"] {
  --tone: var(--warm);
  --tone-soft: rgba(246, 225, 195, 0.24);
}

.receiver__art,
#signal-field,
.receiver__veil {
  inset: 0;
  position: absolute;
}

.receiver__art {
  z-index: -3;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: 58% center;
  opacity: 0.24;
  filter: blur(22px) saturate(0.92) contrast(1.08);
  transform: scale(1.12);
  transition: filter 900ms ease, transform 1200ms ease;
}

.receiver.has-signal .receiver__art {
  opacity: 0.3;
  filter: blur(18px) saturate(1.18) contrast(1.12) brightness(1.06);
  transform: scale(1.16);
}

.receiver[data-tone="coral"].has-signal .receiver__art {
  filter: blur(18px) saturate(1.32) contrast(1.14) brightness(1.08) hue-rotate(-8deg);
}

.receiver[data-tone="lime"].has-signal .receiver__art {
  filter: blur(18px) saturate(1.28) contrast(1.16) brightness(1.1) hue-rotate(12deg);
}

.receiver[data-tone="warm"].has-signal .receiver__art {
  filter: blur(18px) saturate(1.16) sepia(0.12) contrast(1.12) brightness(1.06);
}

.receiver.is-receiving .receiver__art {
  animation: retune-art 1100ms ease-out;
}

#signal-field {
  z-index: -2;
  width: 100%;
  height: 100%;
}

.receiver__veil {
  z-index: -1;
  background:
    radial-gradient(circle at 54% 42%, transparent 0 17%, rgba(4, 8, 8, 0.1) 30%, rgba(3, 5, 5, 0.72) 79%),
    linear-gradient(180deg, rgba(3, 4, 4, 0.18), rgba(3, 5, 5, 0.84));
  transition: background 900ms ease;
}

.receiver.has-signal .receiver__veil {
  background:
    radial-gradient(circle at 58% 44%, transparent 0 24%, rgba(4, 8, 8, 0.08) 38%, rgba(3, 5, 5, 0.62) 82%),
    linear-gradient(180deg, rgba(3, 4, 4, 0.08), rgba(3, 5, 5, 0.72));
}

.masthead {
  position: absolute;
  top: clamp(20px, 3vw, 38px);
  left: clamp(20px, 3vw, 38px);
  z-index: 10;
}

.masthead__mark {
  margin: 0;
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--muted);
  text-transform: uppercase;
}

.visualizer-console {
  position: fixed;
  bottom: clamp(20px, 4vh, 40px);
  left: 50%;
  transform: translateX(-50%);
  width: min(420px, 88%);
  z-index: 1000;
}

.console {
  border-top: none;
  padding-top: 0;
}

.console__entry {
  display: grid;
  grid-template-columns: 1fr 76px;
  gap: 8px;
  align-items: stretch;
}

input[type="text"],
button {
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 19px; /* 38px 高度的完美半圆圆角 */
}

input[type="text"] {
  height: 38px;
  padding: 0 16px;
  outline: none;
  background: rgba(8, 14, 14, 0.42);
  color: var(--paper);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  transition: border-color 220ms ease, box-shadow 220ms ease;
  width: 100%;
  font-size: 13px;
}

input[type="text"]::placeholder {
  color: rgba(237, 246, 242, 0.32);
}

input[type="text"]:focus {
  border-color: color-mix(in srgb, var(--tone) 58%, white 8%);
  box-shadow: 0 0 0 1px var(--tone-soft), 0 0 36px var(--tone-soft);
}

button {
  cursor: pointer;
  min-width: 0;
  color: #071010;
  background: var(--tone);
  font-weight: 700;
  font-size: 14px;
  box-shadow: 0 4px 12px var(--tone-soft);
  transition: transform 180ms ease, filter 180ms ease, box-shadow 180ms ease;
}

button:hover,
button:focus-visible {
  filter: brightness(1.08);
  transform: translateY(-1px);
}

button:disabled {
  cursor: wait;
  filter: saturate(0.72);
  opacity: 0.76;
  transform: none;
}

.echo-output {
  margin-top: 10px;
  text-align: center;
  pointer-events: none;
}

.echo-output p {
  margin: 0 0 6px 0;
  font-family: "Times New Roman", "Songti SC", "STSong", serif;
  font-size: 13px;
  line-height: 1.5;
  color: var(--paper);
  text-shadow: 0 0 12px rgba(255, 255, 255, 0.16);
}

.echo-output__meta {
  display: flex;
  justify-content: center;
  gap: 12px;
  font-size: 10px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.echo-output__meta span {
  color: var(--tone);
  transition: color 300ms ease;
}

@media (max-width: 760px) {
  .receiver__art {
    object-position: 63% center;
  }

  .visualizer-console {
    width: 90%;
    bottom: 16px;
  }

  .console__entry {
    grid-template-columns: 1fr 64px;
    gap: 6px;
  }

  input[type="text"],
  button {
    border-radius: 17px;
  }

  input[type="text"] {
    padding: 0 12px;
    height: 34px;
    font-size: 12px;
  }

  .echo-output p {
    font-size: 11px;
  }
}