/* ── Design tokens ─────────────────────────────────────────── */
:root {
  --bg:           #07090f;
  --surface:      #0d1117;
  --card:         #111827;
  --card-hover:   #161f30;
  --border:       #1e2a3a;
  --border-light: #263145;
  --accent:       #818cf8;
  --accent-dark:  #6366f1;
  --accent-glow:  rgba(129, 140, 248, 0.12);
  --cyan:         #22d3ee;
  --green:        #34d399;
  --text:         #e2e8f0;
  --text-muted:   #94a3b8;
  --text-dim:     #64748b;
  --radius:       12px;
  --radius-sm:    8px;
  --nav-h:        60px;
}

/* ── Reset & base ──────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 16px);
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 1rem;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { display: block; max-width: 100%; }
a { color: var(--accent); text-decoration: none; }
a:hover { color: #fff; }
ul, ol { list-style: none; }
code {
  font-family: "Cascadia Code", "Fira Code", "Consolas", monospace;
  font-size: .85em;
  background: rgba(255,255,255,.06);
  padding: .1em .4em;
  border-radius: 4px;
}

.container {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ── Nav ───────────────────────────────────────────────────── */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-h);
  background: rgba(7, 9, 15, .85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color .3s;
}
.nav.scrolled { border-bottom-color: var(--border); }

.nav-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  letter-spacing: -.01em;
}
.nav-logo:hover { color: #fff; }
.nav-logo img { border-radius: 6px; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
}
.nav-links a {
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  font-size: .9rem;
  color: var(--text-muted);
  transition: color .2s, background .2s;
}
.nav-links a:hover { color: var(--text); background: rgba(255,255,255,.05); }
.nav-links a.active { color: var(--text); }

.btn-nav {
  padding: 6px 16px !important;
  border: 1px solid var(--border-light) !important;
  border-radius: var(--radius-sm) !important;
  color: var(--text) !important;
  font-size: .875rem !important;
}
.btn-nav:hover { border-color: var(--accent) !important; color: var(--accent) !important; background: var(--accent-glow) !important; }

/* ── Buttons ───────────────────────────────────────────────── */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  background: var(--accent-dark);
  color: #fff;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: .95rem;
  transition: background .2s, transform .15s;
}
.btn-primary:hover { background: var(--accent); color: #fff; transform: translateY(-1px); }
.btn-primary.btn-large { padding: 16px 40px; font-size: 1.05rem; }

.btn-ghost {
  display: inline-flex;
  align-items: center;
  padding: 12px 20px;
  color: var(--text-muted);
  border-radius: var(--radius-sm);
  font-size: .95rem;
  transition: color .2s;
}
.btn-ghost:hover { color: var(--text); }

.btn-outline-sm {
  display: inline-flex;
  align-items: center;
  padding: 8px 18px;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-size: .875rem;
  transition: border-color .2s, color .2s;
}
.btn-outline-sm:hover { border-color: var(--accent); color: var(--accent); }

/* ── Badge ─────────────────────────────────────────────────── */
.badge {
  display: inline-block;
  padding: 4px 12px;
  background: rgba(129, 140, 248, .1);
  border: 1px solid rgba(129, 140, 248, .25);
  border-radius: 999px;
  color: var(--accent);
  font-size: .8rem;
  font-weight: 500;
  letter-spacing: .01em;
  margin-bottom: 20px;
}

/* ── Hero ──────────────────────────────────────────────────── */
.hero {
  padding: 100px 0 80px;
  overflow: hidden;
}

.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-text h1 {
  font-size: clamp(2.4rem, 5vw, 3.6rem);
  font-weight: 800;
  letter-spacing: -.03em;
  line-height: 1.1;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #fff 40%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-sub {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 480px;
  margin-bottom: 36px;
  line-height: 1.7;
}

.hero-cta {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.hero-visual {
  display: flex;
  justify-content: center;
}

.screen-wrap {
  position: relative;
  padding: 12px;
  background: var(--card);
  border: 1px solid var(--border-light);
  border-radius: 16px;
  box-shadow:
    0 0 0 1px rgba(255,255,255,.04),
    0 40px 80px rgba(0,0,0,.6),
    0 0 80px var(--accent-glow);
}

.hero-img {
  max-height: 560px;
  width: auto;
  border-radius: 8px;
  display: block;
  margin: 0 auto;
}

/* ── Features ──────────────────────────────────────────────── */
.features {
  padding: 40px 0 80px;
  border-bottom: 1px solid var(--border);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.feature-card {
  padding: 28px 24px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color .2s;
}
.feature-card:hover { border-color: var(--border-light); }

.feature-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  margin-bottom: 16px;
  box-shadow: 0 0 8px var(--accent);
}

.feature-card h3 {
  font-size: .95rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text);
}

.feature-card p {
  font-size: .875rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ── Section shared ────────────────────────────────────────── */
.section { padding: 96px 0; }
.section-alt { background: var(--surface); }

.section-head {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 64px;
}
.section-head h2 {
  font-size: clamp(1.8rem, 3.5vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -.02em;
  margin-bottom: 12px;
}
.section-head p {
  color: var(--text-muted);
  font-size: 1.05rem;
  line-height: 1.7;
}

/* ── Panels grid ───────────────────────────────────────────── */
.panels-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.panel-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color .2s, transform .2s;
}
.panel-card:hover {
  border-color: var(--border-light);
  transform: translateY(-2px);
}

.panel-img-wrap {
  background: #0a0f1a;
  padding: 16px;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  min-height: 160px;
  border-bottom: 1px solid var(--border);
}
.panel-img-wrap img {
  max-height: 220px;
  width: auto;
  object-fit: contain;
}

.panel-body {
  padding: 20px 22px 22px;
}
.panel-body h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 8px;
}
.panel-body > p {
  font-size: .875rem;
  color: var(--text-muted);
  margin-bottom: 14px;
  line-height: 1.6;
}
.panel-body ul {
  display: flex;
  flex-direction: column;
  gap: 5px;
  margin-bottom: 14px;
}
.panel-body ul li {
  font-size: .82rem;
  color: var(--text-muted);
  padding-left: 14px;
  position: relative;
}
.panel-body ul li::before {
  content: "·";
  position: absolute;
  left: 0;
  color: var(--accent);
}

.source-tag {
  display: inline-block;
  padding: 2px 10px;
  background: rgba(129, 140, 248, .08);
  border: 1px solid rgba(129, 140, 248, .18);
  border-radius: 999px;
  font-size: .75rem;
  color: var(--accent);
  font-family: "Cascadia Code", monospace;
}

/* ── Dialogs ───────────────────────────────────────────────── */
.dialogs-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.dialog-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color .2s, transform .2s;
}
.dialog-card:hover {
  border-color: var(--border-light);
  transform: translateY(-2px);
}

.dialog-img-wrap {
  background: #0a0f1a;
  padding: 20px;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  border-bottom: 1px solid var(--border);
  min-height: 180px;
}
.dialog-img {
  max-height: 280px;
  width: auto;
  object-fit: contain;
  border-radius: 6px;
  box-shadow: 0 4px 20px rgba(0,0,0,.4);
}

.dialog-body {
  padding: 22px 24px 26px;
}
.dialog-body h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 10px;
}
.dialog-body > p {
  font-size: .875rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 14px;
}
.dialog-body ul {
  display: flex;
  flex-direction: column;
  gap: 5px;
}
.dialog-body ul li {
  font-size: .82rem;
  color: var(--text-muted);
  padding-left: 14px;
  position: relative;
}
.dialog-body ul li::before {
  content: "·";
  position: absolute;
  left: 0;
  color: var(--accent);
}

/* ── Download ──────────────────────────────────────────────── */
.download-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
  align-items: start;
}

.download-box {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
}
.download-box h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 20px;
  color: var(--text);
}

.req-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.req-list li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  font-size: .9rem;
  color: var(--text-muted);
}
.req-check {
  color: var(--green);
  font-weight: 700;
  flex-shrink: 0;
  margin-top: 1px;
}

.steps {
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.steps li {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}
.step-num {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  background: var(--accent-glow);
  border: 1px solid rgba(129, 140, 248, .3);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .8rem;
  font-weight: 700;
  color: var(--accent);
  margin-top: 2px;
}
.steps strong {
  display: block;
  font-size: .9rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 4px;
}
.steps p {
  font-size: .85rem;
  color: var(--text-muted);
  line-height: 1.55;
}

.download-cta {
  grid-column: 1 / -1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 40px;
  background: linear-gradient(135deg, rgba(99,102,241,.08) 0%, rgba(34,211,238,.05) 100%);
  border: 1px solid rgba(129,140,248,.2);
  border-radius: var(--radius);
  text-align: center;
}

.download-note {
  font-size: .85rem;
  color: var(--text-dim);
}
.download-note a { color: var(--text-muted); }
.download-note a:hover { color: var(--accent); }

/* ── Support ───────────────────────────────────────────────── */
.support-layout {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 28px;
  align-items: start;
}

.support-box {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
}
.support-box h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 20px;
}
.support-box > p {
  font-size: .9rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  line-height: 1.6;
}
.support-box .steps { margin-bottom: 28px; }

.diag-table-wrap {
  overflow-x: auto;
  margin-top: 24px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}
.diag-table {
  width: 100%;
  border-collapse: collapse;
  font-size: .82rem;
}
.diag-table th, .diag-table td {
  padding: 10px 14px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}
.diag-table th {
  background: rgba(255,255,255,.03);
  color: var(--text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: .04em;
  font-size: .75rem;
}
.diag-table td { color: var(--text-muted); }
.diag-table td:first-child { color: var(--text); }
.diag-table tr:last-child td { border-bottom: none; }
.diag-table tr:hover td { background: rgba(255,255,255,.02); }

.privacy-note {
  margin-top: 14px;
  font-size: .8rem;
  color: var(--text-dim);
  line-height: 1.6;
}

.channel-card {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 18px 20px;
  background: rgba(255,255,255,.03);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  color: var(--text);
  transition: border-color .2s, background .2s;
}
.channel-card:hover {
  border-color: var(--accent);
  background: var(--accent-glow);
  color: var(--text);
}
.channel-card svg { flex-shrink: 0; color: var(--text-muted); }
.channel-card:hover svg { color: var(--accent); }
.channel-card strong { display: block; font-size: .9rem; margin-bottom: 2px; }
.channel-card span:not(.arrow) { font-size: .8rem; color: var(--text-dim); }
.channel-card .arrow { margin-left: auto; color: var(--text-dim); font-size: 1.1rem; }

.tech-docs-link {
  margin-top: 24px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}
.tech-docs-link h3 { font-size: 1rem; margin-bottom: 8px; }
.tech-docs-link > p {
  font-size: .875rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 16px;
}

/* ── Footer ────────────────────────────────────────────────── */
.footer {
  border-top: 1px solid var(--border);
  padding: 32px 0;
  background: var(--surface);
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  font-size: .9rem;
  color: var(--text-muted);
}

.footer-links {
  display: flex;
  gap: 20px;
}
.footer-links a {
  font-size: .85rem;
  color: var(--text-dim);
}
.footer-links a:hover { color: var(--text-muted); }

.footer-copy {
  font-size: .8rem;
  color: var(--text-dim);
}

/* ── Responsive ────────────────────────────────────────────── */
@media (max-width: 1024px) {
  .panels-grid { grid-template-columns: repeat(2, 1fr); }
  .features-grid { grid-template-columns: repeat(2, 1fr); }
}

.signing-layout {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 28px;
  align-items: start;
}

.signing-box {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
}
.signing-box h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 20px;
}
.signing-box > p {
  font-size: .9rem;
  color: var(--text-muted);
  margin-bottom: 16px;
  line-height: 1.6;
}

@media (max-width: 860px) {
  .hero-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero-sub { margin-left: auto; margin-right: auto; }
  .hero-cta { justify-content: center; }
  .hero-visual { margin-top: 8px; }
  .hero-img { max-height: 400px; }

  .dialogs-grid { grid-template-columns: 1fr; }
  .download-layout { grid-template-columns: 1fr; }
  .support-layout { grid-template-columns: 1fr; }
  .signing-layout { grid-template-columns: 1fr; }
}

@media (max-width: 600px) {
  .nav-links li:not(:last-child) a { display: none; }
  .panels-grid { grid-template-columns: 1fr; }
  .features-grid { grid-template-columns: 1fr 1fr; }
  .hero { padding: 60px 0 40px; }
  .section { padding: 64px 0; }
  .download-cta { padding: 28px 20px; }
}

@media (max-width: 420px) {
  .features-grid { grid-template-columns: 1fr; }
}