/* ────────────────────────────────────────────
   DESIGN TOKENS — shared with iso3200.net
   ──────────────────────────────────────────── */
:root {
  --bg:           #1e104e;
  --bg-mid:       #452e5a;
  --bg-card:      #261447;
  --bg-input:     #1a0d40;
  --accent:       #ff653f;
  --gold:         #ffc85c;
  --text:         #e8e0f8;
  --text-muted:   #9b8ab8;
  --border:       rgba(255, 200, 92, 0.10);
  --border-input: rgba(232, 224, 248, 0.22);
  --warning:      #ff8f6b;

  --glow-sm:  0 0 10px rgba(255, 101, 63, 0.45), 0 0 4px rgba(255, 101, 63, 0.6);

  --font-head: 'Black Han Sans', 'Impact', sans-serif;
  --font-body: 'Space Mono', 'Courier New', monospace;

  --container: 720px;
  --nav-h:     64px;
  --pin-gap:   12px;
}

/* Focus scrolling keeps fields clear of the pinned result; set from JS. */
html { scroll-padding-bottom: var(--pinned-h, 0px); }

/* ────────────────────────────────────────────
   RESET & BASE
   ──────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: var(--font-body);
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--text);
  background-color: var(--bg);
  background-image:
    radial-gradient(ellipse at 82% 8%,  rgba(69, 46, 90, 0.95) 0%, transparent 52%),
    radial-gradient(ellipse at 18% 92%, rgba(69, 46, 90, 0.80) 0%, transparent 48%);
  background-attachment: fixed;
  min-height: 100vh;
}

a { color: var(--gold); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--accent); }

p { margin-bottom: 1rem; }
p:last-child { margin-bottom: 0; }

h1, h2 {
  font-family: var(--font-head);
  font-weight: normal;
  line-height: 1.0;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

[hidden] { display: none !important; }

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 1rem;
}

/* ────────────────────────────────────────────
   NAVIGATION
   ──────────────────────────────────────────── */
.site-nav {
  position: sticky;
  top: 0;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  background: rgba(30, 16, 78, 0.88);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
}
.site-nav .container {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.nav-logo {
  font-family: var(--font-head);
  font-size: 1.45rem;
  color: var(--text);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.nav-logo span { color: var(--accent); }
.nav-app {
  font-size: 0.62rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-muted);
}

/* ────────────────────────────────────────────
   PAGE HEAD
   ──────────────────────────────────────────── */
.page-head { padding: 3rem 0 2rem; }
.eyebrow {
  font-size: 0.62rem;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.6rem;
}
.eyebrow::before { content: '▶ '; font-size: 0.42rem; vertical-align: middle; }
.page-head h1 {
  font-size: clamp(2.2rem, 7vw, 3.4rem);
  margin-bottom: 1rem;
}
.lede { color: var(--text-muted); max-width: 34em; }

/* ────────────────────────────────────────────
   PANELS & FIELDS
   ──────────────────────────────────────────── */
.mixer { display: grid; gap: 1.25rem; }

.panel {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-top: 2px solid rgba(69, 46, 90, 0.8);
  padding: 1.5rem;
}
.panel h2 {
  font-size: 1.3rem;
  margin-bottom: 1rem;
}
.panel-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
}
.hint {
  color: var(--text-muted);
  font-size: 0.75rem;
  margin: -0.5rem 0 1rem;
}

.row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.field { display: block; min-width: 0; }
.field-label {
  display: block;
  font-size: 0.62rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.35rem;
}

.input-unit {
  display: flex;
  align-items: stretch;
  background: var(--bg-input);
  border: 1px solid var(--border-input);
  transition: border-color 0.2s, box-shadow 0.2s;
}
.input-unit:focus-within {
  border-color: var(--gold);
  box-shadow: 0 0 14px rgba(255, 200, 92, 0.15);
}
.input-unit:has(.is-invalid) { border-color: var(--accent); }

.input-unit input {
  flex: 1;
  min-width: 0;
  width: 100%;
  background: transparent;
  border: 0;
  outline: 0;
  color: var(--text);
  font-family: var(--font-body);
  font-size: 1.1rem;
  padding: 0.6rem 0.75rem;
}
.unit {
  display: flex;
  align-items: center;
  padding: 0 0.75rem;
  color: var(--text-muted);
  font-size: 0.8rem;
}

/* ────────────────────────────────────────────
   PARTS LIST
   ──────────────────────────────────────────── */
.parts {
  list-style: none;
  display: grid;
  gap: 1rem;
  margin-bottom: 1.25rem;
}
.part {
  display: grid;
  grid-template-columns: 1fr 1fr 2.5rem;
  grid-template-areas:
    "head    head head"
    "vol     temp remove"
    "derived .    .";
  gap: 0.35rem 1rem;
  align-items: end;
}
.part-head {
  grid-area: head;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.part-name {
  font-size: 0.7rem;
  color: var(--gold);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.part .field:nth-of-type(1) { grid-area: vol; }
.part .field:nth-of-type(2) { grid-area: temp; }
.part-derived {
  grid-area: derived;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.mode-toggle {
  display: inline-flex;
  border: 1px solid var(--border-input);
}
.mode-toggle button {
  background: transparent;
  border: 0;
  color: var(--text-muted);
  font-family: var(--font-body);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  padding: 0.4rem 0.8rem;
  cursor: pointer;
  transition: color 0.2s, background 0.2s;
}
.mode-toggle button + button { border-left: 1px solid var(--border-input); }
.mode-toggle button:hover { color: var(--gold); }
.mode-toggle button[aria-pressed="true"] {
  background: rgba(255, 200, 92, 0.12);
  color: var(--gold);
}

.unit-prefix { padding-right: 0; }

.btn-remove {
  grid-area: remove;
  height: 2.75rem;
  background: transparent;
  border: 1px solid var(--border-input);
  color: var(--text-muted);
  font-size: 1.3rem;
  line-height: 1;
  cursor: pointer;
  transition: color 0.2s, border-color 0.2s;
}
.btn-remove:hover { color: var(--accent); border-color: var(--accent); }

/* ────────────────────────────────────────────
   BUTTONS
   ──────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-body);
  font-size: 0.68rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  padding: 0.8rem 1.4rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: color 0.2s, border-color 0.2s, box-shadow 0.2s;
}
.btn-outline {
  background: transparent;
  color: var(--text);
  border-color: var(--border-input);
}
.btn-outline:hover {
  color: var(--gold);
  border-color: var(--gold);
  box-shadow: 0 0 18px rgba(255, 200, 92, 0.18);
}

/* ────────────────────────────────────────────
   RESULT
   ──────────────────────────────────────────── */
/* Pinned just above the bottom of the window until scrolled to its place. */
.panel-result {
  border-top-color: var(--accent);
  position: sticky;
  bottom: var(--pin-gap);
  z-index: 10;
  transition: box-shadow 0.25s;
}
.panel-result.is-pinned {
  box-shadow: 0 -10px 36px rgba(0, 0, 0, 0.55), 0 0 22px rgba(255, 101, 63, 0.15);
}

.result {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.25rem 1rem;
}
.result-figure { display: flex; align-items: baseline; gap: 0.75rem; }
.result-value {
  font-family: var(--font-head);
  font-size: clamp(1.8rem, 6vw, 2.4rem);
  line-height: 1.1;
  color: var(--text);
}
.result-label { color: var(--text-muted); }
.result-main .result-value {
  font-size: clamp(2.6rem, 10vw, 3.6rem);
  color: var(--gold);
  text-shadow: 0 0 22px rgba(255, 200, 92, 0.25);
}
.result.is-warning .result-main .result-value {
  color: var(--warning);
  text-shadow: none;
}

.message {
  margin-top: 1rem;
  padding-left: 0.75rem;
  border-left: 2px solid var(--text-muted);
  color: var(--text-muted);
  font-size: 0.8rem;
}
.message-warning { border-left-color: var(--accent); color: var(--warning); }

/* ────────────────────────────────────────────
   SPLIT BETWEEN TWO SOURCES
   ──────────────────────────────────────────── */
.split summary {
  cursor: pointer;
  list-style: none;
  font-size: 0.68rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text);
  transition: color 0.2s;
}
.split summary::-webkit-details-marker { display: none; }
.split summary::before {
  content: '▶';
  display: inline-block;
  margin-right: 0.6rem;
  font-size: 0.5rem;
  color: var(--accent);
  vertical-align: middle;
  transition: transform 0.2s;
}
.split[open] summary::before { transform: rotate(90deg); }
.split summary:hover { color: var(--gold); }
.split[open] summary { margin-bottom: 1rem; }

.split-result {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.25rem 1rem;
  margin-top: 1.25rem;
}
.split-figure { display: flex; align-items: baseline; gap: 0.5rem; }
.split-value {
  font-family: var(--font-head);
  font-size: clamp(1.6rem, 6vw, 2.1rem);
  line-height: 1.1;
  color: var(--gold);
}
.split-plus { color: var(--text-muted); }
.split-result.is-warning .split-value { color: var(--text-muted); }

/* ────────────────────────────────────────────
   NOTES
   ──────────────────────────────────────────── */
.notes {
  margin-top: 3rem;
  color: var(--text-muted);
  font-size: 0.8rem;
}
.notes h2 {
  font-size: 1.1rem;
  color: var(--text);
  margin-bottom: 0.75rem;
}

/* ────────────────────────────────────────────
   FOOTER
   ──────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  margin-top: 4rem;
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}
.footer-logo {
  font-family: var(--font-head);
  font-size: 1.15rem;
  color: var(--text-muted);
  text-transform: uppercase;
}
.footer-logo span { color: var(--accent); }
.footer-copy {
  font-size: 0.68rem;
  color: var(--text-muted);
  letter-spacing: 0.04em;
}

@media (max-width: 420px) {
  .row { grid-template-columns: 1fr; }
  .panel { padding: 1.25rem 1rem; }
}