:root {
  /* Switch states */
  --color-on:        #FF8C42;
  --color-off:       #1A1A2E;
  --color-glow:      #FFB347;

  /* Surface */
  --color-metal:     #8C8C8C;
  --color-metal-hi:  #B0B0B0;
  --color-metal-lo:  #5A5A5A;

  /* Typography */
  --font-counter:    'iA Writer Mono', monospace;
  --font-ui:         'iA Writer Quattro', sans-serif;

  /* Timing */
  --switch-duration: 200ms;
  --switch-easing:   cubic-bezier(0.34, 1.56, 0.64, 1);
  --glow-duration:   500ms;
  --cursor-lerp:     100ms;

  /* ---- Theme tokens (dark = OFF) ---- */
  --bg:              #1A1A1E;
  --text-primary:    #999;
  --text-secondary:  #666;
  --text-tertiary:   #444;
  --color-counter:   #D4D0C8;
  --counter-glow:    rgba(212, 208, 200, 0.08);
  --card-bg:         rgba(255, 255, 255, 0.03);
  --card-border:     rgba(255, 255, 255, 0.07);
  --code-bg:         rgba(255, 255, 255, 0.04);
  --code-border:     rgba(255, 255, 255, 0.07);
  --code-color:      #999;
  --endpoint-color:  #8FBCB8;
  --response-color:  #bbb;
  --copy-color:      #666;
  --copy-bg:         rgba(255, 255, 255, 0.06);
  --copy-border:     rgba(255, 255, 255, 0.08);
  --footer-border:   rgba(255, 255, 255, 0.06);
  --footer-color:    #444;
  --subscribe-bg:    linear-gradient(to bottom, transparent 0%, rgba(0,0,0,0.15) 10%, rgba(0,0,0,0.15) 100%);
  --online-dot:      #8FBCB8;
  --online-dot-glow: rgba(143, 188, 184, 0.3);
}

/* ============ App shell ============ */

.app {
  position: relative;
  width: 100%;
  min-height: 100%;
  /* Wall texture as image layers (transparent → shows through to bg-color) */
  background-image:
    repeating-linear-gradient(0deg,
      transparent 0px, transparent 2px,
      rgba(128, 128, 128, 0.018) 2px, rgba(128, 128, 128, 0.018) 2.5px),
    repeating-linear-gradient(87deg,
      transparent 0px, transparent 3px,
      rgba(128, 128, 128, 0.014) 3px, rgba(128, 128, 128, 0.014) 3.3px),
    repeating-linear-gradient(175deg,
      transparent 0px, transparent 8px,
      rgba(128, 128, 128, 0.008) 8px, rgba(128, 128, 128, 0.008) 12px);
  background-color: var(--bg);
  transition: background-color var(--glow-duration) ease, color var(--glow-duration) ease;
  cursor: default;
  user-select: none;
  -webkit-user-select: none;
}

/* Room vignette — simulates overhead light source */
.app::before {
  content: '';
  position: fixed;
  inset: 0;
  background: radial-gradient(
    ellipse 80% 70% at 50% 40%,
    transparent 0%,
    rgba(0, 0, 0, 0.18) 100%
  );
  pointer-events: none;
  z-index: 0;
  transition: opacity var(--glow-duration) ease;
}

.app.on::before {
  background: radial-gradient(
    ellipse 80% 70% at 50% 40%,
    transparent 0%,
    rgba(0, 0, 0, 0.06) 100%
  );
}

/* ---- Light mode (ON) ---- */
.app.on {
  --bg:              #F5F0EB;
  --text-primary:    #555;
  --text-secondary:  #888;
  --text-tertiary:   #bbb;
  --color-counter:   #222;
  --counter-glow:    rgba(0, 0, 0, 0.05);
  --card-bg:         rgba(0, 0, 0, 0.03);
  --card-border:     rgba(0, 0, 0, 0.08);
  --code-bg:         rgba(0, 0, 0, 0.04);
  --code-border:     rgba(0, 0, 0, 0.08);
  --code-color:      #444;
  --endpoint-color:  #0E7C6B;
  --response-color:  #333;
  --copy-color:      #777;
  --copy-bg:         rgba(0, 0, 0, 0.05);
  --copy-border:     rgba(0, 0, 0, 0.1);
  --footer-border:   rgba(0, 0, 0, 0.06);
  --footer-color:    #bbb;
  --subscribe-bg:    linear-gradient(to bottom, transparent 0%, rgba(0,0,0,0.03) 10%, rgba(0,0,0,0.03) 100%);
  --online-dot:      #22AA22;
  --online-dot-glow: rgba(34, 170, 34, 0.3);

  background-color: var(--bg);
}

.ambient-glow {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -60%);
  width: 800px;
  height: 800px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 179, 71, 0.10) 0%, transparent 70%);
  opacity: 0;
  transition: opacity var(--glow-duration) ease;
  pointer-events: none;
  z-index: 0;
}

.app.on .ambient-glow {
  background: radial-gradient(
    circle,
    rgba(255, 200, 100, 0.14) 0%,
    rgba(255, 170, 60, 0.05) 40%,
    transparent 70%
  );
  opacity: 1;
}

/* ============ Header ============ */

.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 28px;
  z-index: 10;
  pointer-events: none;
}

.header > * {
  pointer-events: auto;
}

.header-title {
  font-family: var(--font-ui);
  font-size: 0.75rem;
  font-weight: 400;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  transition: color var(--glow-duration) ease;
}

.header-online {
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-ui);
  font-size: 0.7rem;
  color: var(--text-secondary);
  transition: color var(--glow-duration) ease;
}

.online-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--online-dot);
  box-shadow: 0 0 6px var(--online-dot-glow);
  animation: pulse-dot 2s ease-in-out infinite;
  transition: background var(--glow-duration) ease, box-shadow var(--glow-duration) ease;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.online-count {
  color: var(--text-primary);
  transition: color var(--glow-duration) ease;
}

.online-label {
  color: var(--text-secondary);
  transition: color var(--glow-duration) ease;
}

/* ============ Hero (first screen) ============ */

.hero {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  min-height: 100dvh;
  gap: 48px;
  padding: 80px 20px 60px;
}

/* Counter */
.counter {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  opacity: 0.7;
  transition: opacity 0.3s ease;
}

.counter-value {
  font-family: var(--font-counter);
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-counter);
  letter-spacing: 0.05em;
  text-shadow: 0 0 10px var(--counter-glow);
  font-variant-numeric: tabular-nums;
  min-width: 3ch;
  text-align: center;
  transition: color var(--glow-duration) ease, text-shadow var(--glow-duration) ease;
}

.counter-label {
  font-family: var(--font-ui);
  font-size: 0.7rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.2em;
  transition: color var(--glow-duration) ease;
}

/* Scroll hint */
.scroll-hint {
  position: absolute;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  color: var(--text-tertiary);
  transition: color 0.3s ease;
  animation: hint-bob 2.5s ease-in-out infinite;
}

.scroll-hint:hover {
  color: var(--text-secondary);
}

.scroll-hint-text {
  font-family: var(--font-ui);
  font-size: 0.6rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
}

.scroll-hint-arrow {
  width: 14px;
  height: 10px;
}

@keyframes hint-bob {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(4px); }
}

/* ============ Subscribe section (below fold) ============ */

.subscribe {
  position: relative;
  z-index: 2;
  padding: 80px 20px 100px;
  background: var(--subscribe-bg);
  transition: background var(--glow-duration) ease;
}

.subscribe-inner {
  max-width: 640px;
  margin: 0 auto;
}

.subscribe-title {
  font-family: var(--font-ui);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-primary);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  margin-bottom: 8px;
  transition: color var(--glow-duration) ease;
}

.subscribe-desc {
  font-family: var(--font-ui);
  font-size: 0.7rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 40px;
  transition: color var(--glow-duration) ease;
}

/* API grid */
.api-grid {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.api-card {
  padding: 16px;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 8px;
  transition: background var(--glow-duration) ease, border-color var(--glow-duration) ease;
}

.api-label {
  display: block;
  font-family: var(--font-ui);
  font-size: 0.6rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 8px;
  transition: color var(--glow-duration) ease;
}

.api-code-row {
  position: relative;
}

.api-endpoint {
  display: block;
  width: 100%;
  padding: 10px 70px 10px 12px;
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: 4px;
  font-family: var(--font-counter);
  font-size: 0.75rem;
  color: var(--endpoint-color);
  word-break: break-all;
  transition: background var(--glow-duration) ease, border-color var(--glow-duration) ease, color var(--glow-duration) ease;
}

.api-response {
  padding: 10px 12px;
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: 4px;
  font-family: var(--font-counter);
  font-size: 0.7rem;
  color: var(--response-color);
  white-space: pre;
  margin: 0;
  transition: background var(--glow-duration) ease, border-color var(--glow-duration) ease, color var(--glow-duration) ease;
}

.api-code {
  display: block;
  width: 100%;
  padding: 10px 12px;
  padding-right: 70px;
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: 4px;
  font-family: var(--font-counter);
  font-size: 0.65rem;
  color: var(--code-color);
  white-space: pre;
  overflow-x: auto;
  margin: 0;
  line-height: 1.5;
  transition: background var(--glow-duration) ease, border-color var(--glow-duration) ease, color var(--glow-duration) ease;
}

.api-copy {
  position: absolute;
  top: 8px;
  right: 8px;
  padding: 4px 10px;
  font-family: var(--font-ui);
  font-size: 0.6rem;
  color: var(--copy-color);
  background: var(--copy-bg);
  border: 1px solid var(--copy-border);
  border-radius: 4px;
  cursor: pointer;
  transition: color 0.15s, background 0.15s;
}

.api-copy:hover {
  color: var(--text-primary);
  background: var(--card-bg);
}

.api-copy.copied {
  color: #33FF33;
  border-color: rgba(51, 255, 51, 0.2);
}

/* ============ Footer ============ */

.footer {
  padding: 40px 28px;
  text-align: center;
  border-top: 1px solid var(--footer-border);
  transition: border-color var(--glow-duration) ease;
}

.footer-text {
  font-family: var(--font-ui);
  font-size: 0.6rem;
  color: var(--footer-color);
  letter-spacing: 0.1em;
  transition: color var(--glow-duration) ease;
}

/* Allow text selection in subscribe section */
.subscribe {
  user-select: text;
  -webkit-user-select: text;
}

/* ============ Mobile ============ */

@media (max-width: 480px) {
  .header {
    padding: 14px 16px;
  }

  .header-title {
    font-size: 0.65rem;
  }

  .header-online {
    font-size: 0.6rem;
  }

  .subscribe {
    padding: 60px 16px 80px;
  }

  .api-card {
    padding: 12px;
  }

  .api-endpoint {
    font-size: 0.6rem;
    padding-right: 12px;
  }

  .api-copy {
    position: static;
    margin-top: 8px;
    display: inline-block;
  }
}