:root {
  color-scheme: light dark;
  --bg: #f7f7f9;
  --panel: #ffffff;
  --panel-alt: #fbfbfd;
  --text: #15161a;
  --muted: #6a6b76;
  --border: #e3e4ea;
  --accent: #4f46e5;
  --accent-hover: #4338ca;
  --accent-fg: #ffffff;
  --danger: #c2183c;
  --ring: rgba(79, 70, 229, 0.35);
  --shadow: 0 1px 2px rgba(15, 16, 26, 0.05), 0 8px 24px rgba(15, 16, 26, 0.05);
  --radius: 14px;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e0f13;
    --panel: #16181e;
    --panel-alt: #1b1e25;
    --text: #e8e9ee;
    --muted: #9a9cab;
    --border: #282b34;
    --accent: #7c7cf5;
    --accent-hover: #8f8ef8;
    --accent-fg: #0e0f13;
    --danger: #ff7a90;
    --ring: rgba(124, 124, 245, 0.4);
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 12px 32px rgba(0, 0, 0, 0.35);
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: clamp(1.5rem, 4vw, 3.5rem) 1rem;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}

main {
  max-width: 46rem;
  margin: 0 auto;
  display: grid;
  gap: 1.25rem;
}

/* ------------------------------------------------------------- masthead */

.masthead {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.masthead-text { display: grid; gap: 0.4rem; }

h1 {
  margin: 0;
  font-size: clamp(1.35rem, 3.4vw, 1.75rem);
  font-weight: 620;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.sub {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
  max-width: 38rem;
}

/* --------------------------------------------------------------- buttons */

button {
  font: inherit;
  color: var(--text);
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.5rem 1.1rem;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, opacity 0.15s;
}

button:hover:not(:disabled) { border-color: var(--muted); }
button:disabled { opacity: 0.45; cursor: not-allowed; }

button.primary {
  background: var(--accent);
  border-color: transparent;
  color: var(--accent-fg);
  font-weight: 560;
}

button.primary:hover:not(:disabled) { background: var(--accent-hover); border-color: transparent; }

:where(button, input, select, textarea, a):focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.icon-button {
  flex: none;
  width: 2.5rem;
  height: 2.5rem;
  padding: 0;
  display: grid;
  place-items: center;
  border-radius: 999px;
  color: var(--muted);
}

.icon-button:hover { color: var(--text); }
.icon-button svg { width: 1.2rem; height: 1.2rem; }

/* -------------------------------------------------------------- status */

.statusbar { display: grid; gap: 0.5rem; }

#status {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
  font-family: var(--mono);
}

#status[data-error] { color: var(--danger); font-weight: 600; }

progress {
  appearance: none;
  width: 100%;
  height: 3px;
  border: none;
  border-radius: 999px;
  background: var(--border);
  overflow: hidden;
}

progress::-webkit-progress-bar { background: var(--border); }
progress::-webkit-progress-value { background: var(--accent); transition: width 0.2s; }
progress::-moz-progress-bar { background: var(--accent); }

/* --------------------------------------------------------------- cards */

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1rem;
  display: grid;
  gap: 0.75rem;
}

.field-label {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
}

textarea, input, select {
  font: inherit;
  color: var(--text);
  background: var(--panel-alt);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.55rem 0.7rem;
}

textarea {
  width: 100%;
  font-family: var(--mono);
  font-size: 0.95rem;
  resize: vertical;
}

.actions { display: flex; gap: 0.6rem; }

output {
  display: block;
  min-height: 9rem;
  white-space: pre-wrap;
  padding: 1rem 1.1rem;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  font-family: var(--mono);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* -------------------------------------------------------------- meters */

.meters {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(8.5rem, 1fr));
  gap: 0.6rem;
}

.meter {
  display: grid;
  gap: 0.2rem;
  padding: 0.6rem 0.75rem;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
}

.meter-label {
  font-size: 0.72rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--muted);
}

.meter-value {
  font-family: var(--mono);
  font-size: 0.92rem;
  overflow-wrap: anywhere;
}

/* ------------------------------------------------------------ citation */

.citation {
  color: var(--muted);
  font-size: 0.82rem;
  border-top: 1px solid var(--border);
  padding-top: 1rem;
}

.citation cite { font-style: italic; }
.citation a { color: inherit; text-decoration-color: var(--border); }
.citation a:hover { color: var(--text); }

/* -------------------------------------------------------------- dialog */

dialog {
  width: min(30rem, calc(100vw - 2rem));
  padding: 0;
  color: var(--text);
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

dialog::backdrop { background: rgba(10, 11, 16, 0.45); backdrop-filter: blur(2px); }

.settings-form { display: grid; gap: 1.1rem; padding: 1rem 1.25rem 1.25rem; }

.settings-head { display: flex; align-items: center; justify-content: space-between; }
.settings-head h2 { margin: 0; font-size: 1.05rem; font-weight: 620; }

fieldset {
  margin: 0;
  padding: 0;
  border: none;
  display: grid;
  gap: 0.7rem;
}

legend {
  padding: 0;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--muted);
}

.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(8rem, 1fr)); gap: 0.7rem; }

.settings-form label {
  display: grid;
  gap: 0.3rem;
  font-size: 0.88rem;
  color: var(--muted);
}

.settings-form input[type="number"], .settings-form select { width: 100%; }

.switch {
  grid-template-columns: auto 1fr;
  align-items: start;
  gap: 0.6rem;
  cursor: pointer;
}

.switch input { width: 1.05rem; height: 1.05rem; margin-top: 0.2rem; accent-color: var(--accent); }
.switch span { color: var(--text); display: grid; gap: 0.15rem; }
.switch small { color: var(--muted); font-size: 0.78rem; }
.switch input:disabled + span { opacity: 0.5; }

.settings-foot { display: flex; justify-content: flex-end; }

@media (max-width: 30rem) {
  .actions { flex-direction: column; }
  .actions button { width: 100%; }
}