:root {
  color-scheme: light;
  /* SF Pro family with system fallbacks; Noto Sans KR keeps Korean optically aligned */
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
    "Helvetica Neue", "Noto Sans KR", sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;

  /* Palette — premium minimalism */
  --charcoal: #1d1d1f;
  --black: #000000;
  --white: #ffffff;
  --snow: #f5f5f7;
  --light-gray: #e8e8ed;
  --aluminum: #86868b;
  --accent: #2997ff;
  --button-blue: #0071e3;
  --link-blue: #0066cc;
  --live: #1d8247;
  --standby: #86868b;
  --danger: #b3261e;

  color: var(--charcoal);
  background: var(--white);

  /* 4px base grid: 4 8 11 15 22 44 84 128 */
  --panel-border: var(--light-gray);
  --panel-bg: var(--white);
  --shadow: rgba(0, 0, 0, 0.22) 3px 5px 30px;
}

/* Dark theme — token overrides; resolved to an explicit data-theme by JS.
   Semantic hues are lifted for legibility but desaturated so they read calm,
   not neon, on the dark surface; only the primary CTA stays vivid. */
:root[data-theme="dark"] {
  color-scheme: dark;
  --charcoal: #f5f5f7;
  --black: #ffffff;
  --white: #1c1c1e;
  --snow: #0a0a0b;
  --light-gray: #38383a;
  --aluminum: #a1a1a6;
  --accent: #5aa9ff;
  --button-blue: #0a84ff;
  --link-blue: #6cb4ff;
  --live: #5fd98c;
  --standby: #a1a1a6;
  --danger: #ff6b61;
  --panel-border: #38383a;
  --shadow: rgba(0, 0, 0, 0.6) 3px 5px 30px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--snow);
  letter-spacing: -0.022em;
}

.page {
  min-height: 100vh;
  padding: 44px 22px;
}

.page-shell {
  width: min(100%, 980px);
  margin: 0 auto;
  display: grid;
  gap: 22px;
  align-content: start;
}

.panel {
  padding: 44px;
  border: 1px solid var(--panel-border);
  border-radius: 11px;
  background: var(--panel-bg);
}

.panel.is-active-panel {
  border-color: rgba(0, 0, 0, 0.16);
  box-shadow: var(--shadow);
}

.panel.is-complete {
  border-color: rgba(29, 130, 71, 0.28);
}

.hero-panel {
  display: flex;
  justify-content: space-between;
  gap: 22px;
  align-items: flex-start;
}

.eyebrow {
  margin: 0 0 11px;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--aluminum);
}

h1 {
  margin: 0 0 15px;
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.08;
}

h2 {
  margin: 0;
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

p {
  margin: 0;
  line-height: 1.47;
}

.lede {
  font-size: 1.0625rem;
  color: var(--charcoal);
}

.muted {
  color: var(--aluminum);
  font-size: 0.9375rem;
}

.section-head {
  display: flex;
  justify-content: space-between;
  gap: 15px;
  align-items: flex-start;
  margin-bottom: 22px;
}

.section-kicker {
  margin-bottom: 4px;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--aluminum);
}

.stack {
  display: grid;
}

.gap-sm {
  gap: 8px;
}

.gap-md {
  gap: 15px;
}

.action-row {
  display: flex;
  gap: 11px;
  align-items: center;
  flex-wrap: wrap;
}

/* Pill button — 980px radius, 44px minimum target */
.button {
  border: 0;
  border-radius: 980px;
  min-height: 44px;
  padding: 0 22px;
  font: inherit;
  font-size: 1.0625rem;
  font-weight: 400;
  letter-spacing: -0.022em;
  cursor: pointer;
  transition: background-color 0.2s ease, opacity 0.2s ease;
}

.button:disabled {
  cursor: not-allowed;
  opacity: 0.36;
}

.button-primary {
  color: var(--white);
  background: var(--button-blue);
}

.button-secondary {
  color: var(--link-blue);
  background: var(--light-gray);
}

.button-primary:hover:not(:disabled),
.button-secondary:hover:not(:disabled) {
  opacity: 0.85;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 15px;
  border-radius: 980px;
  background: var(--snow);
  color: var(--aluminum);
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 15px;
  border: 1px solid var(--light-gray);
  border-radius: 980px;
  background: var(--white);
  color: var(--charcoal);
  font: inherit;
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  cursor: pointer;
  transition: opacity 0.2s ease;
}

.theme-toggle:hover {
  opacity: 0.7;
}

.theme-toggle-icon {
  font-size: 1rem;
  line-height: 1;
}

.step-strip {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 4px;
}

.step-chip {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 0 15px;
  border: 1px solid var(--light-gray);
  border-radius: 980px;
  background: var(--white);
  color: var(--aluminum);
  font-size: 0.9375rem;
  font-weight: 400;
}

.step-chip-number {
  display: inline-grid;
  place-items: center;
  width: 22px;
  height: 22px;
  border-radius: 980px;
  background: var(--light-gray);
  color: var(--aluminum);
  font-size: 0.8125rem;
  font-weight: 600;
}

.step-chip.is-active {
  border-color: var(--charcoal);
  background: var(--charcoal);
  color: var(--white);
}

.step-chip.is-active .step-chip-number {
  background: var(--white);
  color: var(--charcoal);
}

.step-chip.is-complete {
  border-color: rgba(29, 130, 71, 0.3);
  background: rgba(29, 130, 71, 0.06);
  color: var(--live);
}

.step-chip.is-complete .step-chip-number {
  background: var(--live);
  color: var(--white);
}

.channel-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 11px;
}

.channel-grid-compact {
  margin-bottom: 0;
}

.channel-card {
  display: grid;
  gap: 11px;
  padding: 22px;
  border: 1px solid var(--light-gray);
  border-radius: 11px;
  background: var(--white);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.channel-card.is-selected {
  border-color: var(--charcoal);
  box-shadow: var(--shadow);
}

.channel-card.is-disabled {
  opacity: 0.4;
}

.channel-top {
  display: flex;
  justify-content: space-between;
  gap: 11px;
  align-items: center;
}

.channel-name {
  font-size: 1.0625rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.status-chip {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 4px 11px;
  border-radius: 980px;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.status-chip.is-live {
  color: var(--live);
  background: rgba(29, 130, 71, 0.1);
}

.status-chip.is-standby {
  color: var(--aluminum);
  background: var(--light-gray);
}

.status-board {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 11px;
  margin-bottom: 22px;
}

.status-card {
  display: grid;
  gap: 4px;
  padding: 22px;
  border-radius: 11px;
  background: var(--snow);
}

.status-card strong {
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.status-label {
  font-size: 0.8125rem;
  color: var(--aluminum);
}

.audio-player {
  width: 100%;
  margin-top: 4px;
}

.field {
  display: grid;
  gap: 8px;
}

.field span {
  font-size: 0.9375rem;
  font-weight: 600;
}

.field input {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--light-gray);
  border-radius: 11px;
  padding: 0 15px;
  font: inherit;
  font-size: 1.0625rem;
  background: var(--white);
  color: var(--charcoal);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.field input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(41, 151, 255, 0.25);
}

.error-text {
  margin: 0;
  padding: 15px 18px;
  border-radius: 11px;
  background: rgba(179, 38, 30, 0.08);
  color: var(--danger);
  font-weight: 600;
}

.step-note {
  padding: 15px 18px;
  border-radius: 11px;
  background: var(--snow);
}

.success-note {
  color: var(--live);
  background: rgba(29, 130, 71, 0.08);
  font-weight: 600;
}

.qr-layout {
  display: grid;
  grid-template-columns: minmax(180px, 240px) 1fr;
  gap: 22px;
  align-items: center;
}

.qr-frame {
  display: grid;
  place-items: center;
  min-height: 220px;
  border: 1px solid var(--light-gray);
  border-radius: 11px;
  background: var(--snow);
}

.qr-frame img {
  width: 100%;
  max-width: 220px;
  height: auto;
}

.event-log {
  display: grid;
  gap: 8px;
}

.event-row {
  padding: 15px 18px;
  border-radius: 11px;
  background: var(--snow);
}

.meter-block {
  display: grid;
  gap: 11px;
  margin-bottom: 22px;
}

.meter-header {
  display: flex;
  justify-content: space-between;
  gap: 15px;
  align-items: center;
  font-weight: 600;
}

.meter-track {
  width: 100%;
  height: 8px;
  border-radius: 980px;
  background: var(--light-gray);
  overflow: hidden;
}

.meter-bar {
  width: 0%;
  height: 100%;
  border-radius: 980px;
  background: var(--accent);
  transition: width 0.1s linear;
}

@media (max-width: 720px) {
  .page {
    padding: 22px 15px;
  }

  .panel {
    padding: 22px;
  }

  .hero-panel,
  .section-head {
    display: grid;
  }

  .step-strip {
    display: grid;
  }
}