:root {
  --bg: #060a12;
  --bg-elevated: #0d1424;
  --bg-card: #111a2e;
  --border: rgba(255, 255, 255, 0.08);
  --text: #e8edf7;
  --text-muted: #8b9bb8;
  --accent: #00e5c7;
  --accent-dim: rgba(0, 229, 199, 0.15);
  --coral: #ff6b4a;
  --coral-dim: rgba(255, 107, 74, 0.15);
  --amber: #f5b942;
  --green: #3dd68c;
  --font-display: "Syne", system-ui, sans-serif;
  --font-body: "DM Sans", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, monospace;
  --radius: 14px;
  --shadow: 0 24px 80px rgba(0, 0, 0, 0.45);
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  overflow-x: hidden;
}

.bg-grid {
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, black, transparent);
  pointer-events: none;
  z-index: 0;
}

.bg-glow {
  position: fixed;
  width: 600px;
  height: 600px;
  border-radius: 50%;
  filter: blur(120px);
  opacity: 0.35;
  pointer-events: none;
  z-index: 0;
}
.bg-glow--a { top: -200px; left: -100px; background: #00e5c7; }
.bg-glow--b { top: 40%; right: -200px; background: #4f46e5; opacity: 0.2; }

.header, .main, .footer {
  position: relative;
  z-index: 1;
  max-width: 920px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 1.5rem;
  padding-bottom: 1rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  color: var(--text);
}
.logo__mark {
  width: 2rem;
  height: 2rem;
  color: var(--accent);
}
.logo__mark svg { width: 100%; height: 100%; }
.logo__text {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.03em;
}
.logo__text em {
  font-style: normal;
  color: var(--accent);
}

.header__nav {
  display: flex;
  gap: 1.5rem;
}
.header__nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.2s;
}
.header__nav a:hover { color: var(--accent); }

.hero {
  padding: 2.5rem 0 2rem;
  text-align: center;
}
.hero__eyebrow {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--accent);
  margin: 0 0 1rem;
}
.hero__title {
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 6vw, 3.4rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.04em;
  margin: 0 0 1rem;
}
.gradient-text {
  background: linear-gradient(135deg, var(--accent), #7dd3fc);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero__sub {
  color: var(--text-muted);
  max-width: 36rem;
  margin: 0 auto;
  font-size: 1.05rem;
}

.scanner { padding-bottom: 4rem; }

.scanner__panel {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  box-shadow: var(--shadow);
}

.scanner__toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.75rem;
}
.scanner__label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-muted);
}
.word-count {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.textarea-wrap {
  position: relative;
  border-radius: 10px;
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
}
.textarea-wrap:focus-within {
  border-color: rgba(0, 229, 199, 0.4);
  box-shadow: 0 0 0 3px var(--accent-dim);
}

textarea {
  display: block;
  width: 100%;
  min-height: 200px;
  padding: 1rem 1.1rem;
  border: none;
  background: transparent;
  color: var(--text);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.65;
  resize: vertical;
  outline: none;
}
textarea::placeholder { color: #5a6a85; }

.scan-line {
  position: absolute;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  opacity: 0;
  top: 0;
  pointer-events: none;
}
.scan-line.active {
  opacity: 1;
  animation: scan 1.8s ease-in-out infinite;
}
@keyframes scan {
  0% { top: 0; opacity: 0; }
  10% { opacity: 1; }
  90% { opacity: 1; }
  100% { top: 100%; opacity: 0; }
}

.scanner__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-top: 1rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.65rem 1.2rem;
  border-radius: 10px;
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: transform 0.15s, box-shadow 0.15s, background 0.15s;
}
.btn:active { transform: scale(0.98); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.btn--primary {
  background: linear-gradient(135deg, #00c9ad, #00e5c7);
  color: #042a24;
  box-shadow: 0 4px 24px rgba(0, 229, 199, 0.25);
}
.btn--primary:hover:not(:disabled) {
  box-shadow: 0 6px 32px rgba(0, 229, 199, 0.4);
}

.btn--secondary {
  background: var(--bg-elevated);
  color: var(--text);
  border: 1px solid var(--border);
}
.btn--secondary:hover:not(:disabled) {
  border-color: rgba(0, 229, 199, 0.35);
  background: var(--accent-dim);
}

.btn--ghost {
  background: transparent;
  color: var(--text-muted);
}
.btn--ghost:hover { color: var(--text); }

.scanner__hint {
  margin: 0.85rem 0 0;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.empty-state {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--text-muted);
}
.empty-state__icon {
  font-size: 2.5rem;
  opacity: 0.3;
  margin-bottom: 0.75rem;
}

.results { margin-top: 1.5rem; animation: fadeUp 0.5s ease; }
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.gauge-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1rem;
}

.gauge {
  position: relative;
  max-width: 280px;
  margin: 0 auto 1rem;
}
.gauge__svg { width: 100%; height: auto; display: block; }
.gauge__track {
  fill: none;
  stroke: rgba(255,255,255,0.08);
  stroke-width: 12;
  stroke-linecap: round;
}
.gauge__fill {
  fill: none;
  stroke: url(#gaugeGrad);
  stroke-width: 12;
  stroke-linecap: round;
  stroke-dasharray: 251.2;
  stroke-dashoffset: 251.2;
  transition: stroke-dashoffset 1s cubic-bezier(0.4, 0, 0.2, 1), stroke 0.3s;
}

.gauge__center {
  position: absolute;
  left: 50%;
  bottom: 8px;
  transform: translateX(-50%);
  text-align: center;
}
.gauge__pct {
  display: block;
  font-family: var(--font-display);
  font-size: 2.5rem;
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.04em;
}
.gauge__label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.verdict { text-align: center; margin-bottom: 1.25rem; }
.verdict__badge {
  display: inline-block;
  padding: 0.35rem 0.9rem;
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.5rem;
}
.verdict__badge--human { background: rgba(61, 214, 140, 0.15); color: var(--green); }
.verdict__badge--uncertain { background: rgba(245, 185, 66, 0.15); color: var(--amber); }
.verdict__badge--ai { background: var(--coral-dim); color: var(--coral); }
.verdict__copy { margin: 0; color: var(--text-muted); font-size: 0.95rem; }

.meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
}
.meta-pill {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.4rem 0.75rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}
.meta-pill strong {
  color: var(--text);
  font-family: var(--font-mono);
  font-weight: 500;
  margin-left: 0.25rem;
}

.deep-card, .signals-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  margin-bottom: 1rem;
}
.deep-card h3, .signals-card h3 {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  margin: 0 0 1rem;
  letter-spacing: -0.02em;
}

.deep-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}
@media (max-width: 500px) { .deep-grid { grid-template-columns: 1fr; } }

.deep-stat {
  background: var(--bg-elevated);
  border-radius: 10px;
  padding: 1rem;
  border: 1px solid var(--border);
}
.deep-stat__label {
  display: block;
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 0.35rem;
}
.deep-stat__value {
  font-family: var(--font-mono);
  font-size: 1.35rem;
  font-weight: 500;
}
.deep-stat__tag {
  display: inline-block;
  margin-top: 0.35rem;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 0.15rem 0.45rem;
  border-radius: 4px;
  background: rgba(255,255,255,0.06);
  color: var(--text-muted);
}

.deep-warning {
  margin: 1rem 0 0;
  font-size: 0.85rem;
  color: var(--amber);
}

.signals {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 0.6rem;
}

.signal {
  padding: 0.75rem 0.9rem;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  transition: border-color 0.2s, background 0.2s;
}
.signal--on {
  border-color: rgba(255, 107, 74, 0.45);
  background: var(--coral-dim);
}
.signal__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.25rem;
}
.signal__name {
  font-size: 0.85rem;
  font-weight: 600;
}
.signal__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: rgba(255,255,255,0.15);
  flex-shrink: 0;
}
.signal--on .signal__dot {
  background: var(--coral);
  box-shadow: 0 0 8px var(--coral);
}
.signal__detail {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin: 0;
  line-height: 1.4;
}

.disclaimer {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-align: center;
  padding: 0.5rem 1rem 2rem;
  border-top: 1px solid var(--border);
  margin-top: 0.5rem;
}

.how {
  padding: 3rem 0 4rem;
  border-top: 1px solid var(--border);
}

.seo {
  padding: 0 0 3rem;
  max-width: 40rem;
  margin: 0 auto;
}
.seo h2 {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 700;
  margin: 0 0 1rem;
  letter-spacing: -0.02em;
}
.seo p {
  color: var(--text-muted);
  font-size: 0.92rem;
  line-height: 1.65;
  margin: 0 0 1rem;
}
.seo p:last-child { margin-bottom: 0; }

.how h2 {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 800;
  text-align: center;
  margin: 0 0 2rem;
  letter-spacing: -0.03em;
}
.how__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
}
.how__card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}
.how__num {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--accent);
  letter-spacing: 0.1em;
}
.how__card h3 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  margin: 0.5rem 0;
}
.how__card p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.footer {
  padding: 2rem 1.25rem 3rem;
  text-align: center;
  border-top: 1px solid var(--border);
}
.footer p { margin: 0.25rem 0; color: var(--text-muted); font-size: 0.9rem; }
.footer__fine { font-size: 0.75rem !important; opacity: 0.7; }

.scanner.is-scanning .btn { pointer-events: none; }