:root {
  --bg-0: #05060f;
  --bg-1: #0b0d1a;
  --bg-2: #12162a;
  --glass: rgba(255, 255, 255, 0.04);
  --glass-brd: rgba(255, 255, 255, 0.08);
  --text: #e8ecff;
  --text-dim: #8a90b8;
  --accent: #7cf9ff;
  --accent-2: #a56cff;
  --accent-3: #ff6cc7;
  --success: #6bff9e;
  --warn: #ffb86c;
  --danger: #ff6b6b;
  --radius: 14px;
  --shadow: 0 20px 60px rgba(0, 0, 0, 0.6);
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="light"] {
  --bg-0: #f5f6ff;
  --bg-1: #eef1ff;
  --bg-2: #dee3ff;
  --glass: rgba(255, 255, 255, 0.6);
  --glass-brd: rgba(0, 0, 0, 0.08);
  --text: #0b0d1a;
  --text-dim: #4a4f78;
  --shadow: 0 20px 60px rgba(100, 100, 200, 0.15);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html, body {
  height: 100%;
  font-family: 'SF Mono', 'JetBrains Mono', 'Menlo', 'Consolas', ui-monospace, monospace;
  color: var(--text);
  background: var(--bg-0);
  overflow-x: hidden;
  transition: background var(--transition), color var(--transition);
  -webkit-font-smoothing: antialiased;
}

body {
  background:
    radial-gradient(ellipse 80% 60% at 20% 0%, rgba(124, 249, 255, 0.12), transparent 50%),
    radial-gradient(ellipse 60% 50% at 80% 30%, rgba(165, 108, 255, 0.12), transparent 50%),
    radial-gradient(ellipse 70% 60% at 50% 100%, rgba(255, 108, 199, 0.08), transparent 50%),
    linear-gradient(180deg, var(--bg-0), var(--bg-1) 50%, var(--bg-2));
  min-height: 100vh;
  position: relative;
}

#particle-bg {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  z-index: 0;
  pointer-events: none;
  opacity: 0.6;
}

/* TOPBAR */
.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 2rem;
  backdrop-filter: blur(20px) saturate(1.4);
  -webkit-backdrop-filter: blur(20px) saturate(1.4);
  background: linear-gradient(180deg, rgba(5, 6, 15, 0.7), rgba(5, 6, 15, 0.3));
  border-bottom: 1px solid var(--glass-brd);
}

[data-theme="light"] .topbar {
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.7), rgba(255, 255, 255, 0.3));
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  font-size: 0.85rem;
}

.logo-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 12px var(--accent), 0 0 24px var(--accent);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.3); opacity: 0.7; }
}

.brand-text {
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.live-clock {
  font-variant-numeric: tabular-nums;
  font-size: 0.85rem;
  color: var(--text-dim);
  padding: 0.4rem 0.8rem;
  background: var(--glass);
  border: 1px solid var(--glass-brd);
  border-radius: 8px;
}

.btn-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--glass);
  border: 1px solid var(--glass-brd);
  color: var(--text);
  cursor: pointer;
  font-size: 1.1rem;
  transition: var(--transition);
}

.btn-icon:hover {
  background: rgba(255, 255, 255, 0.1);
  transform: rotate(15deg);
}

/* MAIN */
main {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
  display: grid;
  gap: 1.5rem;
}

/* HERO */
.hero {
  padding: 4rem 2rem 3rem;
  text-align: left;
}

.eyebrow {
  color: var(--accent);
  font-size: 0.8rem;
  letter-spacing: 0.2em;
  margin-bottom: 1rem;
  opacity: 0.8;
}

.hero-title {
  font-size: clamp(2rem, 6vw, 4.5rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: 1.5rem;
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
}

.hero-title em {
  font-style: italic;
  font-weight: 300;
  color: var(--text-dim);
}

.gradient-text {
  background: linear-gradient(90deg, var(--accent), var(--accent-2), var(--accent-3));
  background-size: 200% 100%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradient-shift 6s ease infinite;
}

@keyframes gradient-shift {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

.hero-sub {
  color: var(--text-dim);
  max-width: 620px;
  font-size: 1.05rem;
  line-height: 1.7;
  margin-bottom: 2rem;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1rem;
  margin-top: 2.5rem;
}

.stat {
  padding: 1rem 1.25rem;
  background: var(--glass);
  border: 1px solid var(--glass-brd);
  border-radius: var(--radius);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.stat-label {
  display: block;
  font-size: 0.7rem;
  letter-spacing: 0.15em;
  color: var(--text-dim);
  margin-bottom: 0.4rem;
}

.stat-value {
  display: block;
  font-size: 1.4rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--accent);
}

/* CARDS */
.card {
  padding: 2rem;
  background: var(--glass);
  border: 1px solid var(--glass-brd);
  border-radius: var(--radius);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: var(--shadow);
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s, transform 0.6s;
}

.card.revealed {
  opacity: 1;
  transform: translateY(0);
}

.card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.25rem;
  gap: 1rem;
  flex-wrap: wrap;
}

.card-head h2 {
  font-family: 'Inter', system-ui, sans-serif;
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.card-sub {
  color: var(--text-dim);
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.card-hint {
  font-size: 0.75rem;
  color: var(--text-dim);
  letter-spacing: 0.05em;
}

.btn-ghost {
  padding: 0.5rem 1rem;
  background: transparent;
  border: 1px solid var(--glass-brd);
  border-radius: 8px;
  color: var(--text);
  cursor: pointer;
  font-family: inherit;
  font-size: 0.8rem;
  transition: var(--transition);
}

.btn-ghost:hover {
  background: var(--glass);
  border-color: var(--accent);
  color: var(--accent);
}

.btn-primary {
  padding: 0.75rem 1.75rem;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  border: none;
  border-radius: 10px;
  color: #05060f;
  cursor: pointer;
  font-family: inherit;
  font-weight: 700;
  font-size: 0.9rem;
  letter-spacing: 0.05em;
  transition: var(--transition);
  box-shadow: 0 4px 20px rgba(124, 249, 255, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(124, 249, 255, 0.5);
}

.btn-primary:active { transform: translateY(0); }
.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }

/* QUOTE */
.quote-text {
  font-family: 'Inter', system-ui, sans-serif;
  font-size: clamp(1.2rem, 2.5vw, 1.7rem);
  font-weight: 300;
  line-height: 1.4;
  color: var(--text);
  margin: 1rem 0;
  font-style: italic;
  min-height: 3em;
}

.quote-author {
  color: var(--accent);
  font-size: 0.9rem;
  letter-spacing: 0.1em;
}

/* PALETTE */
.palette-swatches {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 0.75rem;
  margin-top: 1rem;
}

.swatch {
  aspect-ratio: 1.4;
  border-radius: 10px;
  display: flex;
  align-items: flex-end;
  padding: 0.75rem;
  color: rgba(0, 0, 0, 0.75);
  font-weight: 700;
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.swatch:hover { transform: translateY(-4px) scale(1.02); }
.swatch.copied::after {
  content: 'COPIED';
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  background: rgba(0, 0, 0, 0.7);
  color: white;
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  font-size: 0.65rem;
}

/* FORM */
.form-row {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 1rem;
  margin-bottom: 1rem;
}

@media (max-width: 500px) {
  .form-row { grid-template-columns: 1fr; }
}

#echo-form label {
  display: block;
  margin-bottom: 1rem;
}

#echo-form label span {
  display: block;
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--text-dim);
  margin-bottom: 0.4rem;
}

#echo-form input,
#echo-form textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid var(--glass-brd);
  border-radius: 10px;
  color: var(--text);
  font-family: inherit;
  font-size: 0.95rem;
  transition: var(--transition);
  resize: vertical;
}

[data-theme="light"] #echo-form input,
[data-theme="light"] #echo-form textarea {
  background: rgba(255, 255, 255, 0.7);
}

#echo-form input:focus,
#echo-form textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(124, 249, 255, 0.15);
}

#echo-form input:user-invalid,
#echo-form textarea:user-invalid {
  border-color: var(--danger);
}

.form-foot {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: 0.5rem;
}

.form-hint {
  font-size: 0.85rem;
  color: var(--text-dim);
}

.form-hint.error { color: var(--danger); }
.form-hint.ok { color: var(--success); }

.result {
  margin-top: 1.25rem;
  padding: 1rem;
  background: rgba(0, 0, 0, 0.4);
  border: 1px solid var(--glass-brd);
  border-radius: 10px;
  color: var(--accent);
  font-size: 0.85rem;
  white-space: pre-wrap;
  overflow-x: auto;
  animation: slide-in 0.3s ease;
}

@keyframes slide-in {
  from { opacity: 0; transform: translateY(-10px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* VITALS */
.badge {
  padding: 0.3rem 0.7rem;
  background: var(--glass);
  border: 1px solid var(--glass-brd);
  border-radius: 100px;
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: var(--success);
}

.badge.live { animation: badge-pulse 2s infinite; }

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

.vitals-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.25rem;
  margin-top: 0.5rem;
}

.vital {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.vital-label {
  font-size: 0.75rem;
  color: var(--text-dim);
  letter-spacing: 0.1em;
}

.bar {
  height: 8px;
  background: rgba(0, 0, 0, 0.4);
  border-radius: 4px;
  overflow: hidden;
  position: relative;
}

.bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  border-radius: 4px;
  width: 0%;
  transition: width 0.5s ease;
  box-shadow: 0 0 10px var(--accent);
}

.vital-detail {
  font-size: 0.8rem;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}

/* CANVAS */
#demo-canvas {
  width: 100%;
  height: 320px;
  border-radius: 10px;
  background: rgba(0, 0, 0, 0.4);
  border: 1px solid var(--glass-brd);
  display: block;
  cursor: crosshair;
}

/* FOOTER */
.footer {
  padding: 2rem;
  text-align: center;
  color: var(--text-dim);
  font-size: 0.8rem;
  border-top: 1px solid var(--glass-brd);
  margin-top: 2rem;
  position: relative;
  z-index: 1;
}

/* REDUCED MOTION */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  #particle-bg { display: none; }
}