:root {
  --bg: #eef1f5;
  --ink: #17212e;
  --muted: #5d6a7b;
  --line: #d3dae3;
  --card: rgba(250, 251, 253, 0.84);
  --tide-glow: #0040ff;
  --font-ui: "Geist", ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "Geist Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0b0f14;
    --ink: #c3cedd;
    --muted: #8593a6;
    --line: #232c38;
    --card: rgba(13, 18, 25, 0.82);
    --tide-glow: #1aadff;
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --bg: #0b0f14;
  --ink: #c3cedd;
  --muted: #8593a6;
  --line: #232c38;
  --card: rgba(13, 18, 25, 0.82);
  --tide-glow: #1aadff;
  color-scheme: dark;
}

* { box-sizing: border-box; }

html, body { height: 100%; margin: 0; }

body {
  background: var(--bg);
  color: var(--ink);
  font: 14px/1.5 var(--font-ui);
}

.stage {
  position: relative;
  min-height: 100%;
  display: grid;
  place-items: center;
  padding-block: 48px;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
  font-family: var(--font-mono);
  color: var(--ink);
  overflow: hidden;
  cursor: crosshair;
}

.card {
  position: relative;
  z-index: 1;
  width: min(460px, 100%);
  display: grid;
  gap: 18px;
  padding: 22px 22px 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  font-family: var(--font-ui);
  cursor: default;
}

.card header { display: grid; gap: 4px; }

.card h1 {
  margin: 0;
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.01em;
  text-wrap: balance;
}

.card p { margin: 0; color: var(--muted); }

kbd {
  font: 12px var(--font-mono);
  padding: 1px 5px;
  border: 1px solid var(--line);
  border-radius: 4px;
}

.controls { display: grid; gap: 10px; }

.control {
  display: grid;
  grid-template-columns: 7.5em minmax(0, 1fr) 5.5em;
  align-items: center;
  gap: 12px;
}

.control label { font-size: 13px; }

.control output {
  font: 12px var(--font-mono);
  color: var(--muted);
  text-align: right;
  font-variant-numeric: tabular-nums;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--tide-glow);
}

.actions { display: flex; flex-wrap: wrap; gap: 8px; }

button {
  font: 500 13px var(--font-ui);
  color: var(--ink);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 7px 12px;
  cursor: pointer;
}

button:hover { border-color: var(--muted); }

button:focus-visible,
input:focus-visible {
  outline: 2px solid var(--tide-glow);
  outline-offset: 2px;
}

button.primary {
  background: var(--tide-glow);
  border-color: var(--tide-glow);
  color: #fff;
}

@media (max-width: 420px) {
  .control { grid-template-columns: 6.5em minmax(0, 1fr) 4.5em; gap: 8px; }
}