/* ══════════════════════════════════════════════════════════
   CS-NET v4 — showcase site (dark tech theme)
   ══════════════════════════════════════════════════════════ */
:root {
  --bg: #070b14;
  --bg-2: #0b1220;
  --panel: #0e1730;
  --panel-2: #111c38;
  --line: rgba(122, 162, 247, 0.14);
  --line-strong: rgba(57, 181, 74, 0.35);
  --txt: #e6edf7;
  --muted: #8fa3c0;
  --green: #39b54a;
  --green-soft: #4cc95e;
  --amber: #fbac18;
  --cyan: #4cc9f0;
  --radius: 14px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
          "PingFang SC", "Microsoft YaHei", sans-serif;
  --mono: ui-monospace, "SF Mono", "Cascadia Code", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--txt);
  font-family: var(--font);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--green-soft); text-decoration: none; }
a:hover { text-decoration: underline; }
code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: rgba(57, 181, 74, 0.12);
  border: 1px solid var(--line-strong);
  border-radius: 5px;
  padding: 0.1em 0.35em;
  color: #9be8a6;
}
section[id] { scroll-margin-top: 72px; }

/* ── buttons ─────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  transition: transform 0.15s ease, box-shadow 0.2s ease, background 0.2s ease;
  cursor: pointer;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-lg { padding: 13px 26px; font-size: 1.02rem; }
.btn-primary {
  background: linear-gradient(135deg, var(--green) 0%, #2e9e41 100%);
  color: #04120a;
  box-shadow: 0 6px 24px rgba(57, 181, 74, 0.28);
}
.btn-primary:hover { box-shadow: 0 8px 32px rgba(57, 181, 74, 0.42); }
.btn-ghost {
  border-color: var(--line-strong);
  color: var(--txt);
  background: rgba(57, 181, 74, 0.06);
}
.btn-ghost:hover { background: rgba(57, 181, 74, 0.14); }

/* ── nav ─────────────────────────────────────────────── */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 50;
  background: rgba(7, 11, 20, 0.75);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s ease, background 0.2s ease;
}
.nav.scrolled { border-bottom-color: var(--line); background: rgba(7, 11, 20, 0.92); }
.nav-inner {
  max-width: 1080px; margin: 0 auto; padding: 12px 24px;
  display: flex; align-items: center; gap: 24px;
}
.brand { display: flex; align-items: center; gap: 10px; color: var(--txt); font-size: 1.15rem; }
.brand b { color: var(--green-soft); }
.brand em {
  font-style: normal; font-size: 0.7rem; font-weight: 700; letter-spacing: 0.06em;
  color: var(--amber); border: 1px solid rgba(251, 172, 24, 0.4); border-radius: 6px;
  padding: 1px 7px; margin-left: 2px;
}
.nav-links { display: flex; gap: 22px; margin-left: 12px; }
.nav-links a { color: var(--muted); font-size: 0.95rem; }
.nav-links a:hover { color: var(--txt); text-decoration: none; }
.nav-cta { margin-left: auto; display: flex; gap: 10px; align-items: center; }

/* ── language toggle ─────────────────────────────────── */
.lang-toggle {
  display: inline-flex; border: 1px solid var(--line-strong); border-radius: 999px;
  overflow: hidden; background: rgba(57, 181, 74, 0.06);
}
.lang-toggle button {
  background: transparent; border: 0; color: var(--muted);
  font-size: 0.78rem; font-weight: 700; padding: 5px 12px; cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease;
  font-family: var(--font);
}
.lang-toggle button:hover { color: var(--txt); }
.lang-toggle button.active { background: rgba(57, 181, 74, 0.20); color: var(--green-soft); }

/* ── hero ────────────────────────────────────────────── */
.hero { position: relative; overflow: hidden; padding: 150px 24px 80px; }
.hero-bg {
  position: absolute; inset: 0; pointer-events: none;
  background:
    radial-gradient(900px 480px at 75% -10%, rgba(57, 181, 74, 0.16), transparent 60%),
    radial-gradient(700px 420px at 12% 8%, rgba(76, 201, 240, 0.10), transparent 60%),
    radial-gradient(1px 1px at 20% 30%, rgba(255,255,255,0.25), transparent),
    radial-gradient(1px 1px at 40% 70%, rgba(255,255,255,0.18), transparent),
    radial-gradient(1px 1px at 70% 25%, rgba(255,255,255,0.22), transparent),
    radial-gradient(1px 1px at 88% 60%, rgba(255,255,255,0.16), transparent),
    linear-gradient(rgba(122,162,247,0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(122,162,247,0.05) 1px, transparent 1px);
  background-size: auto, auto, 180px 180px, 180px 180px, 180px 180px, 180px 180px, 44px 44px, 44px 44px;
  mask-image: radial-gradient(ellipse 90% 80% at 50% 0%, #000 30%, transparent 78%);
}
.hero-inner { position: relative; max-width: 860px; margin: 0 auto; text-align: center; }
.hero-badge {
  display: inline-block; font-size: 0.82rem; letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--green-soft); border: 1px solid var(--line-strong); border-radius: 999px;
  padding: 6px 16px; background: rgba(57, 181, 74, 0.08); margin-bottom: 26px;
}
.hero-badge b { color: var(--amber); }
.hero-title { font-size: clamp(2.1rem, 5.4vw, 3.4rem); line-height: 1.12; font-weight: 800; letter-spacing: -0.02em; }
.hero-title .grad {
  background: linear-gradient(92deg, var(--green-soft), var(--cyan) 60%, var(--amber));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-sub { margin: 26px auto 0; max-width: 720px; color: var(--muted); font-size: 1.08rem; }
.hero-sub b { color: var(--txt); }
.hero-cta { margin-top: 34px; display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.hero-stats {
  margin: 52px auto 0; display: flex; justify-content: center; gap: 14px; flex-wrap: wrap;
}
.stat {
  background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 14px 24px; min-width: 130px;
}
.stat b { display: block; font-size: 1.5rem; color: var(--green-soft); font-weight: 800; }
.stat span { font-size: 0.82rem; color: var(--muted); }

/* ── sections ────────────────────────────────────────── */
.section { padding: 84px 24px; }
.section-alt { background: var(--bg-2); border-block: 1px solid var(--line); }
.section-inner { max-width: 1080px; margin: 0 auto; }
.section-title {
  font-size: clamp(1.5rem, 3vw, 2rem); font-weight: 800; letter-spacing: -0.01em;
  text-align: center; margin-bottom: 10px;
}
.section-title::after {
  content: ""; display: block; width: 64px; height: 3px; margin: 14px auto 0;
  border-radius: 2px; background: linear-gradient(90deg, var(--green), var(--cyan));
}
.section-sub { text-align: center; color: var(--muted); max-width: 660px; margin: 8px auto 0; }
.section-sub a { color: var(--green-soft); }

/* ── gallery screenshots ─────────────────────────────── */
.gallery { margin-top: 40px; display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 20px; }
.shot { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.shot img {
  width: 100%; display: block; aspect-ratio: 2/1; object-fit: contain;
  background: var(--panel-2); border-bottom: 1px solid var(--line);
}
.shot figcaption { padding: 12px 16px; }
.shot figcaption b { display: block; font-size: 0.95rem; }
.shot figcaption span { font-size: 0.82rem; color: var(--muted); }

/* ── feature cards ───────────────────────────────────── */
.cards { margin-top: 42px; display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 20px; }
.card {
  background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px 24px; transition: transform 0.18s ease, border-color 0.18s ease;
}
.card:hover { transform: translateY(-3px); border-color: var(--line-strong); }
.card-icon {
  width: 48px; height: 48px; border-radius: 12px; display: flex; align-items: center; justify-content: center;
  color: var(--green-soft); background: rgba(57, 181, 74, 0.10); border: 1px solid var(--line-strong);
  margin-bottom: 16px;
}
.card h3 { font-size: 1.08rem; margin-bottom: 8px; }
.card p { color: var(--muted); font-size: 0.93rem; }

/* ── models ──────────────────────────────────────────── */
.model-grid { margin-top: 40px; display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 18px; }
.model {
  background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px 20px; position: relative;
}
.model-main { border-color: var(--line-strong); box-shadow: 0 0 34px rgba(57, 181, 74, 0.10); }
.model-tag {
  position: absolute; top: 14px; right: 14px; font-size: 0.68rem; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--amber); border: 1px solid rgba(251, 172, 24, 0.35);
  border-radius: 6px; padding: 2px 8px;
}
.model h3 { font-size: 1rem; font-family: var(--mono); color: var(--green-soft); margin-bottom: 10px; padding-right: 90px; }
.model ul { list-style: none; }
.model li { color: var(--muted); font-size: 0.88rem; padding: 3px 0 3px 18px; position: relative; }
.model li::before { content: "▸"; position: absolute; left: 0; color: var(--green); }
.model-cta { text-align: center; margin-top: 32px; }

/* ── code blocks ─────────────────────────────────────── */
.codeblock {
  margin: 22px auto 0; max-width: 780px; background: #0a0f1d;
  border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden;
}
.codebar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 8px 16px; background: rgba(122, 162, 247, 0.07); border-bottom: 1px solid var(--line);
  font-size: 0.8rem; color: var(--muted); letter-spacing: 0.03em;
}
.copy {
  font-size: 0.74rem; color: var(--muted); background: transparent; border: 1px solid var(--line);
  border-radius: 6px; padding: 3px 12px; cursor: pointer; transition: all 0.15s ease;
}
.copy:hover { color: var(--txt); border-color: var(--line-strong); }
.copy.copied { color: var(--green-soft); border-color: var(--line-strong); }
.codeblock pre {
  padding: 16px 18px; overflow-x: auto; font-size: 0.88rem;
  font-family: var(--mono); color: #b9d8c0; line-height: 1.6;
}
.codeblock code { background: none; border: none; padding: 0; color: inherit; }

/* ── docs ────────────────────────────────────────────── */
.doc-grid { margin-top: 40px; display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 14px; }
.doc {
  background: var(--panel); border: 1px solid var(--line); border-radius: 12px;
  padding: 16px 18px; color: var(--txt); font-weight: 600; display: block;
  transition: border-color 0.15s ease, transform 0.15s ease;
}
.doc:hover { border-color: var(--line-strong); transform: translateY(-2px); text-decoration: none; }
.doc span { display: block; font-weight: 400; font-size: 0.82rem; color: var(--muted); margin-top: 2px; }

/* ── footer ──────────────────────────────────────────── */
.footer { border-top: 1px solid var(--line); padding: 40px 24px; }
.footer-inner { max-width: 1080px; margin: 0 auto; display: flex; align-items: center; gap: 22px; flex-wrap: wrap; }
.footer-brand { display: flex; align-items: center; gap: 10px; font-weight: 700; }
.footer-links { display: flex; gap: 20px; margin-left: auto; }
.footer-links a { color: var(--muted); font-size: 0.9rem; }
.footer-links a:hover { color: var(--txt); }
.footer-meta { width: 100%; color: var(--muted); font-size: 0.82rem; margin-top: 14px; }

/* ── reveal animation ────────────────────────────────── */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity 0.6s ease, transform 0.6s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ── responsive ──────────────────────────────────────── */
@media (max-width: 760px) {
  .nav-links { display: none; }
  .nav-cta .btn-ghost { display: none; }
  .hero { padding-top: 120px; }
  .section { padding: 60px 18px; }
  .footer-links { margin-left: 0; }
}