:root {
  --bg: #0d1117;
  --bg-soft: #11161f;
  --panel: #161b26;
  --border: #262d3d;
  --text: #e6edf3;
  --muted: #9aa7b8;
  --accent: #4da3ff;
  --accent-2: #6ee7b7;
  --code-bg: #0a0e14;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  background:
    radial-gradient(900px 500px at 20% -10%, rgba(77, 163, 255, 0.12), transparent 60%),
    radial-gradient(700px 400px at 90% 0%, rgba(110, 231, 183, 0.07), transparent 60%),
    var(--bg);
  color: var(--text);
  line-height: 1.55;
}

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

.hero { padding: 72px 24px 24px; text-align: center; }

.hero-inner { max-width: 760px; margin: 0 auto; }

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  letter-spacing: 0.02em;
  margin-bottom: 28px;
}

.mark {
  display: inline-grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--accent), #7c5cff);
  color: #fff;
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.05em;
  box-shadow: 0 4px 18px rgba(77, 163, 255, 0.35);
}

.brand-name { font-size: 20px; }

h1 {
  font-size: clamp(30px, 5vw, 46px);
  line-height: 1.15;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.tagline {
  margin: 18px auto 30px;
  max-width: 620px;
  color: var(--muted);
  font-size: 17px;
}

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

.cta {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  padding: 13px 26px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 15px;
  transition: transform 0.12s ease, box-shadow 0.12s ease;
}

.btn:hover { text-decoration: none; transform: translateY(-1px); }

.btn-primary {
  background: linear-gradient(135deg, var(--accent), #7c5cff);
  color: #fff;
  box-shadow: 0 6px 22px rgba(77, 163, 255, 0.35);
}

.btn-primary:hover { box-shadow: 0 8px 28px rgba(77, 163, 255, 0.5); }

.btn-ghost {
  border: 1px solid var(--border);
  color: var(--text);
  background: var(--panel);
}

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

.btn-sub { font-weight: 400; font-size: 12px; opacity: 0.85; }

.hint { margin-top: 16px; font-size: 13px; color: var(--muted); }

/* --- app mock --- */

.app-mock {
  padding: 48px 24px 16px;
  display: flex;
  justify-content: center;
  perspective: 1200px;
}

.mock-win {
  width: min(860px, 100%);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  background: var(--panel);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.55);
  transform: rotateX(2deg);
}

.mock-titlebar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 14px;
  background: var(--bg-soft);
  border-bottom: 1px solid var(--border);
  font-size: 13px;
}

.mock-mark {
  display: grid;
  place-items: center;
  width: 22px;
  height: 22px;
  border-radius: 5px;
  background: linear-gradient(135deg, var(--accent), #7c5cff);
  color: #fff;
  font-size: 10px;
  font-weight: 700;
}

.mock-name { font-weight: 600; }

.mock-id {
  margin-left: auto;
  font-family: Consolas, "Cascadia Mono", monospace;
  font-size: 12px;
  color: var(--muted);
  background: var(--code-bg);
  border: 1px solid var(--border);
  padding: 2px 10px;
  border-radius: 999px;
}

.mock-controls { display: flex; gap: 7px; margin-left: 10px; }
.mock-controls i {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--border);
}
.mock-controls i:last-child { background: #c94f4f; }

.mock-body {
  display: grid;
  grid-template-columns: 46px 230px 1fr;
  min-height: 300px;
}

.mock-activity {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 18px;
  padding-top: 14px;
  background: var(--bg-soft);
  border-right: 1px solid var(--border);
}

.mock-activity svg {
  width: 22px;
  height: 22px;
  fill: none;
  stroke: var(--muted);
  stroke-width: 1.6;
  stroke-linejoin: round;
  stroke-linecap: round;
}

.mock-activity svg:first-child {
  stroke: var(--accent);
  filter: drop-shadow(0 0 6px rgba(77, 163, 255, 0.6));
}

.mock-side {
  padding: 14px;
  border-right: 1px solid var(--border);
  background: var(--panel);
}

.mock-side-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.mock-side-head h2 {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--muted);
}

.mock-plus {
  display: grid;
  place-items: center;
  width: 20px;
  height: 20px;
  border-radius: 5px;
  background: var(--accent);
  color: #fff;
  font-weight: 700;
  font-size: 14px;
}

.mock-pc {
  display: flex;
  gap: 9px;
  align-items: center;
  padding: 8px 9px;
  border-radius: 7px;
  font-size: 13px;
}

.mock-pc.on { background: rgba(77, 163, 255, 0.1); }

.mock-pc strong { display: block; font-weight: 600; font-size: 13px; }
.mock-pc small { color: var(--muted); font-size: 11px; }

.mock-dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--accent-2);
  box-shadow: 0 0 8px rgba(110, 231, 183, 0.7);
  flex: none;
}
.mock-dot.off { background: #4b5563; box-shadow: none; }
.mock-dot.pending { background: #f0b429; box-shadow: 0 0 8px rgba(240, 180, 41, 0.6); }

.mock-main { padding: 14px; }

.mock-crumb {
  font-size: 12px;
  color: var(--muted);
  margin-bottom: 12px;
}

.mock-crumb span { color: var(--border); padding: 0 4px; }

.mock-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: 10px;
}

.mock-item {
  border: 1px solid var(--border);
  border-radius: 9px;
  padding: 14px;
  background: var(--bg-soft);
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 13px;
}

.mock-item svg {
  width: 26px;
  height: 26px;
  fill: none;
  stroke: var(--accent-2);
  stroke-width: 1.5;
  stroke-linejoin: round;
  stroke-linecap: round;
}

.mock-item.file svg { stroke: var(--accent); }

.mock-item small { color: var(--muted); font-size: 11px; }

/* --- features / steps / footer --- */

.features, .steps {
  max-width: 980px;
  margin: 0 auto;
  padding: 70px 24px 0;
}

h2 {
  font-size: 26px;
  text-align: center;
  margin-bottom: 34px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.feature-grid article {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px 22px;
  background: var(--bg-soft);
}

.feature-grid h3 { font-size: 15px; margin-bottom: 8px; }
.feature-grid p { color: var(--muted); font-size: 14px; }

.steps ol {
  list-style: none;
  counter-reset: step;
  display: grid;
  gap: 14px;
}

.steps li {
  counter-increment: step;
  display: flex;
  gap: 16px;
  align-items: baseline;
  color: var(--muted);
  font-size: 15px;
}

.steps li::before {
  content: counter(step);
  flex: none;
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), #7c5cff);
  color: #fff;
  font-weight: 700;
  font-size: 14px;
}

code {
  font-family: Consolas, "Cascadia Mono", monospace;
  font-size: 13px;
  background: var(--code-bg);
  border: 1px solid var(--border);
  padding: 1px 7px;
  border-radius: 6px;
}

footer {
  margin-top: 80px;
  padding: 34px 24px 44px;
  text-align: center;
  border-top: 1px solid var(--border);
  color: var(--text);
}

footer .fine { margin-top: 6px; font-size: 13px; color: var(--muted); }

@media (max-width: 720px) {
  .mock-body { grid-template-columns: 40px 1fr; }
  .mock-side { display: none; }
  .mock-id { display: none; }
}