:root {
  color-scheme: dark;
  font-family: system-ui, -apple-system, "Hiragino Kaku Gothic ProN", "Noto Sans JP", sans-serif;
  background: #101b20;
  color: #e9f0e9;
}
* { box-sizing: border-box; }
body {
  min-height: 100vh; margin: 0;
  background: radial-gradient(circle at 50% 29%, #204044 0, #14272c 31%, #101b20 72%);
}
button, input { font: inherit; }
button { cursor: pointer; }
button:focus-visible, input:focus-visible { outline: 3px solid #b6e6b7; outline-offset: 4px; }
.player {
  width: min(100%, 760px); min-height: 100vh; margin: auto;
  padding: 30px clamp(20px, 6vw, 54px) 24px;
  display: flex; flex-direction: column;
}
.header { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.brand { font-size: 1.5rem; font-weight: 750; letter-spacing: -.07em; }
.brand span { color: #a5d9a8; font-weight: 400; }
.tag { color: #a9bdb8; font-size: .75rem; letter-spacing: .1em; }
.hero { text-align: center; padding: clamp(30px, 5vh, 54px) 0 38px; }
.eyebrow { margin: 0 0 14px; color: #a5d9a8; font-size: .7rem; letter-spacing: .28em; }
h1 { margin: 0; font-size: clamp(1.75rem, 5vw, 2.6rem); font-weight: 550; letter-spacing: .03em; }
h1 span { display: inline-block; }
.intro { margin: 14px 0 0; color: #b6c7c0; font-size: .93rem; line-height: 1.7; }
.dial {
  width: min(48vw, 220px); aspect-ratio: 1; margin: 28px auto 27px; padding: 12px;
  border: 1px solid #77ae9a88; border-radius: 50%;
  box-shadow: 0 0 48px #66c4a026, inset 0 0 28px #66c4a018;
}
.dial-inner {
  width: 100%; height: 100%; display: flex; align-items: center; justify-content: center; gap: 5px;
  border: 1px solid #78ae9a55; border-radius: 50%;
  background: radial-gradient(circle, #2e5554 0, #1a3638 68%, #173033 100%);
}
.frequency { font-size: clamp(3rem, 10vw, 4.6rem); font-weight: 300; font-variant-numeric: tabular-nums; letter-spacing: -.06em; }
.unit { margin-top: 2rem; color: #a9d4b6; font-size: 1rem; }
.playing .dial { box-shadow: 0 0 70px #78cba04d, inset 0 0 28px #66c4a018; }
.play {
  min-width: 210px; padding: 15px 30px; border: 0; border-radius: 100px;
  background: #b7e4b5; color: #10251e; font-size: 1rem; font-weight: 700;
  transition: background .2s, transform .2s;
}
.play:hover { background: #d5f3d0; transform: translateY(-2px); }
.play:disabled { cursor: wait; opacity: .7; }
.status { min-height: 1.5em; margin: 16px 0 0; color: #a9bdb8; font-size: .85rem; }
.controls { padding: 24px clamp(18px, 5vw, 36px); border: 1px solid #a6cab432; border-radius: 20px; background: #11242ac9; }
.control-row { display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.control-row h2, .control-row label { margin: 0; font-size: .96rem; font-weight: 600; }
.control-row p { margin: 5px 0 0; color: #a9bdb8; font-size: .75rem; }
.mode-buttons { display: flex; gap: 6px; padding: 4px; border: 1px solid #a6cab43a; border-radius: 12px; background: #0d1b20; }
.mode-buttons button { padding: 10px 13px; border: 0; border-radius: 8px; background: transparent; color: #b4c8bd; font-size: .8rem; white-space: nowrap; }
.mode-buttons button[aria-pressed="true"] { background: #a5d9a8; color: #10251e; font-weight: 700; }
.mode-description { margin: 15px 0 25px; color: #aac7ba; font-size: .78rem; }
.volume-row { border-top: 1px solid #a6cab42e; padding-top: 23px; }
.volume-row input { flex: 1; max-width: 330px; accent-color: #a5d9a8; }
.volume-row output { min-width: 3em; text-align: right; color: #b9d8c5; font-size: .85rem; font-variant-numeric: tabular-nums; }
footer { margin-top: auto; padding-top: 30px; color: #95aaa4; text-align: center; font-size: .74rem; line-height: 1.7; }
@media (max-width: 570px) {
  .hero { padding-top: 46px; }
  .mode-row { align-items: flex-start; flex-direction: column; gap: 14px; }
  .mode-buttons { width: 100%; }
  .mode-buttons button { flex: 1; }
  .dial { width: min(55vw, 220px); }
}
@media (prefers-reduced-motion: reduce) { .play { transition: none; } }