:root {
  --bg: #0b0f17;
  --surface: #121826;
  --border: #1e293b;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --accent: #8b5cf6;
  --accent2: #22d3ee;
  --danger: #f87171;
  --radius: 14px;
  --font: "DM Sans", system-ui, -apple-system, sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

a {
  color: var(--accent2);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

.wrap {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

header.site {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(11, 15, 23, 0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

header.site .inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 0;
  gap: 1rem;
}

.logo {
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
  color: var(--text);
}
.logo span {
  color: var(--accent);
}

nav a {
  margin-left: 1.25rem;
  color: var(--muted);
  font-size: 0.95rem;
}
nav a:hover {
  color: var(--text);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.25rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  border: none;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s;
}
.btn:active {
  transform: scale(0.98);
}
.btn-primary {
  background: linear-gradient(135deg, var(--accent), #6366f1);
  color: #fff;
  box-shadow: 0 4px 24px rgba(139, 92, 246, 0.35);
}
.btn-primary:hover {
  box-shadow: 0 6px 28px rgba(139, 92, 246, 0.45);
  text-decoration: none;
}
.btn-ghost {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
}
.btn-ghost:hover {
  color: var(--text);
  border-color: var(--muted);
}

.hero {
  padding: 2.5rem 0 3rem;
}

.hero-grid {
  display: grid;
  gap: 2rem;
  align-items: center;
}
@media (min-width: 900px) {
  .hero-grid {
    grid-template-columns: 1fr 1.05fr;
  }
}

.hero h1 {
  font-size: clamp(2rem, 4vw, 2.75rem);
  line-height: 1.15;
  margin: 0 0 1rem;
  letter-spacing: -0.03em;
}

.hero .lead {
  color: var(--muted);
  font-size: 1.1rem;
  margin: 0 0 1.5rem;
  max-width: 36ch;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.hero-visual {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.45);
}
.hero-visual img,
.hero-visual svg {
  display: block;
  width: 100%;
  height: auto;
  vertical-align: middle;
}

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

section h2 {
  font-size: 1.65rem;
  margin: 0 0 1.25rem;
  letter-spacing: -0.02em;
}

.features {
  display: grid;
  gap: 1rem;
}
@media (min-width: 640px) {
  .features {
    grid-template-columns: repeat(3, 1fr);
  }
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.35rem;
}

.card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
}
.card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.reviews-layout {
  display: grid;
  gap: 2rem;
}
@media (min-width: 800px) {
  .reviews-layout {
    grid-template-columns: 1fr 1.1fr;
    align-items: start;
  }
}

.review-form label {
  display: block;
  font-size: 0.85rem;
  color: var(--muted);
  margin-bottom: 0.35rem;
}

.review-form input,
.review-form textarea,
.review-form select {
  width: 100%;
  padding: 0.65rem 0.85rem;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: #0f141c;
  color: var(--text);
  font-family: inherit;
  font-size: 1rem;
  margin-bottom: 1rem;
}

.review-form textarea {
  min-height: 120px;
  resize: vertical;
}

.review-form .hint {
  font-size: 0.8rem;
  color: var(--muted);
  margin: -0.5rem 0 1rem;
}

.review-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.review-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.15rem;
}

.review-item header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
}

.review-item .name {
  font-weight: 600;
}
.review-item .stars {
  color: #fbbf24;
  letter-spacing: 0.05em;
}
.review-item time {
  font-size: 0.8rem;
  color: var(--muted);
}
.review-item p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.empty-reviews {
  color: var(--muted);
  font-style: italic;
  padding: 1rem 0;
}

footer {
  padding: 2rem 0 3rem;
  color: var(--muted);
  font-size: 0.9rem;
  border-top: 1px solid var(--border);
}

footer a {
  color: var(--muted);
}
footer a:hover {
  color: var(--accent2);
}

.msg {
  padding: 0.65rem 1rem;
  border-radius: 10px;
  font-size: 0.9rem;
  margin-bottom: 1rem;
  display: none;
}
.msg.show {
  display: block;
}
.msg.ok {
  background: rgba(34, 211, 153, 0.12);
  border: 1px solid rgba(34, 211, 153, 0.35);
  color: #6ee7b7;
}
.msg.err {
  background: rgba(248, 113, 113, 0.1);
  border: 1px solid rgba(248, 113, 113, 0.35);
  color: var(--danger);
}

.examples-intro {
  color: var(--muted);
  margin: 0 0 1.75rem;
  max-width: 52rem;
  font-size: 0.98rem;
}

.example-scenario {
  margin-bottom: 2.25rem;
}
.example-scenario:last-child {
  margin-bottom: 0;
}

.example-scenario h3 {
  margin: 0 0 1rem;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
}

.dialog {
  border-radius: var(--radius);
  padding: 0.85rem 1.1rem;
  margin-bottom: 0.75rem;
  font-size: 0.95rem;
  line-height: 1.55;
  border: 1px solid var(--border);
}

.dialog-user {
  background: rgba(139, 92, 246, 0.12);
  border-color: rgba(139, 92, 246, 0.35);
}
.dialog-user .label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
  margin-bottom: 0.35rem;
  font-weight: 600;
}

.dialog-system,
.dialog-model {
  background: var(--surface);
}
.dialog-system .label,
.dialog-model .label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent2);
  margin-bottom: 0.35rem;
  font-weight: 600;
}

.dialog-model .label {
  color: var(--muted);
}

.system-steps {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--muted);
  font-size: 0.92rem;
}
.system-steps li {
  margin-bottom: 0.4rem;
}

.model-reply {
  margin: 0;
  color: var(--text);
  white-space: pre-wrap;
  font-size: 0.92rem;
}

.note-box {
  margin-top: 0.85rem;
  padding: 0.75rem 1rem;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: rgba(15, 20, 28, 0.6);
  font-size: 0.85rem;
  color: var(--muted);
}

.note-box strong {
  color: var(--text);
}