/* ============================================================
   Cache-Cat website styles
   Dark, modern, fully responsive (mobile-first friendly)
   ============================================================ */

:root {
  --bg:        #0a0b10;
  --bg-2:      #0f111a;
  --bg-3:      #14172230;
  --surface:   #161a26;
  --surface-2: #1b2030;
  --border:    #262c3d;
  --border-2:  #323a52;
  --text:      #e7eaf3;
  --text-dim:  #9aa3bd;
  --text-mute: #6b7390;
  --brand:     #6c8cff;
  --brand-2:   #a06bff;
  --accent:    #2fe6c4;
  --accent-2:  #ffb84d;
  --grad:      linear-gradient(120deg, #6c8cff 0%, #a06bff 50%, #2fe6c4 100%);
  --radius:    16px;
  --radius-sm: 10px;
  --maxw:      1160px;
  --shadow:    0 20px 50px -20px rgba(0,0,0,.6);
  --font:      'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --mono:      'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, Consolas, monospace;
}

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

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  overflow-x: hidden;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}
.container.narrow { max-width: 820px; }

a { color: inherit; text-decoration: none; }

code {
  font-family: var(--mono);
  font-size: .88em;
  background: var(--surface-2);
  border: 1px solid var(--border);
  padding: 1px 6px;
  border-radius: 6px;
  color: var(--accent);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 999px;
  font-weight: 600;
  font-size: .95rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform .15s ease, box-shadow .2s ease, background .2s ease, border-color .2s ease;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn-primary {
  background: var(--grad);
  color: #0a0b10;
  font-weight: 700;
  box-shadow: 0 10px 30px -10px rgba(108,140,255,.6);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 16px 40px -12px rgba(108,140,255,.7); }
.btn-ghost {
  background: var(--bg-3);
  border-color: var(--border-2);
  color: var(--text);
}
.btn-ghost:hover { border-color: var(--brand); background: var(--surface-2); }
.btn-lg { padding: 16px 32px; font-size: 1.05rem; }

/* ---------- Nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  background: rgba(10,11,16,.72);
  border-bottom: 1px solid transparent;
  transition: border-color .3s ease, background .3s ease;
}
.nav.scrolled { border-bottom-color: var(--border); background: rgba(10,11,16,.9); }
.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 9px;
  font-weight: 800;
  font-size: 1.18rem;
  letter-spacing: -.02em;
}
.brand-mark { font-size: 1.4rem; line-height: 1; }
.brand-text {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.nav-links {
  display: flex;
  gap: 28px;
  margin-left: auto;
  margin-right: 8px;
}
.nav-links a {
  color: var(--text-dim);
  font-weight: 500;
  font-size: .94rem;
  position: relative;
  transition: color .2s ease;
}
.nav-links a:hover { color: var(--text); }
.nav-links a::after {
  content: '';
  position: absolute;
  left: 0; bottom: -6px;
  width: 0; height: 2px;
  background: var(--grad);
  transition: width .25s ease;
  border-radius: 2px;
}
.nav-links a:hover::after { width: 100%; }
.nav-actions { display: flex; align-items: center; gap: 12px; }
.lang-toggle {
  background: var(--bg-3);
  border: 1px solid var(--border-2);
  color: var(--text-dim);
  border-radius: 999px;
  padding: 8px 14px;
  font-weight: 600;
  font-size: .85rem;
  cursor: pointer;
  font-family: var(--font);
  transition: border-color .2s, color .2s;
}
.lang-toggle:hover { border-color: var(--brand); color: var(--text); }
.gh-link { padding: 9px 16px; font-size: .9rem; }
.nav-burger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}
.nav-burger span {
  width: 24px; height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform .25s ease, opacity .25s ease;
}
.nav-burger[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-burger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-burger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  padding: 110px 0 90px;
  text-align: center;
  overflow: hidden;
}
.hero-glow {
  position: absolute;
  top: -200px; left: 50%;
  transform: translateX(-50%);
  width: 900px; height: 700px;
  background: radial-gradient(circle at 50% 40%, rgba(108,140,255,.28), rgba(160,107,255,.14) 35%, transparent 65%);
  filter: blur(40px);
  pointer-events: none;
  z-index: 0;
}
.hero-inner { position: relative; z-index: 1; }
.badge {
  display: inline-block;
  background: var(--bg-3);
  border: 1px solid var(--border-2);
  color: var(--accent);
  border-radius: 999px;
  padding: 7px 16px;
  font-size: .82rem;
  font-weight: 600;
  margin-bottom: 26px;
  letter-spacing: .01em;
}
.hero-title {
  font-size: clamp(2.3rem, 6.5vw, 4.4rem);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -.03em;
  margin-bottom: 22px;
}
.hero-title span { display: block; }
.grad {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-sub {
  max-width: 660px;
  margin: 0 auto 36px;
  color: var(--text-dim);
  font-size: clamp(1rem, 2.4vw, 1.18rem);
}
.hero-cta {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 64px;
}
.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  max-width: 880px;
  margin: 0 auto;
}
.stat {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 14px;
  transition: transform .2s ease, border-color .2s ease;
}
.stat:hover { transform: translateY(-4px); border-color: var(--border-2); }
.stat-num {
  font-size: clamp(1.6rem, 4vw, 2.3rem);
  font-weight: 800;
  letter-spacing: -.02em;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.stat-num .unit { font-size: .55em; }
.stat-label { color: var(--text-mute); font-size: .82rem; margin-top: 6px; }

/* ---------- Intro / VS ---------- */
.intro { padding: 36px 24px 80px; }
.intro-lead {
  max-width: 820px;
  margin: 0 auto 48px;
  text-align: center;
  font-size: clamp(1.05rem, 2.6vw, 1.35rem);
  color: var(--text);
  font-weight: 500;
  line-height: 1.6;
}
.vs-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}
.vs-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px 24px;
  transition: transform .2s ease, border-color .2s ease;
}
.vs-card:hover { transform: translateY(-4px); border-color: var(--brand); }
.vs-card h3 { font-size: 1.05rem; margin-bottom: 10px; color: var(--brand); }
.vs-card p { color: var(--text-dim); font-size: .95rem; }

/* ---------- Sections ---------- */
.section { padding: 90px 0; }
.section-alt { background: var(--bg-2); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.section-head {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 56px;
}
.eyebrow {
  display: inline-block;
  text-transform: uppercase;
  letter-spacing: .14em;
  font-size: .76rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 14px;
}
.section-head h2 {
  font-size: clamp(1.8rem, 4.5vw, 2.7rem);
  font-weight: 800;
  letter-spacing: -.02em;
  line-height: 1.15;
  margin-bottom: 16px;
}
.section-head p { color: var(--text-dim); font-size: 1.05rem; }

/* ---------- Features ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.feature-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px 26px;
  transition: transform .2s ease, border-color .2s ease, box-shadow .2s ease;
  position: relative;
  overflow: hidden;
}
.feature-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--grad);
  opacity: 0;
  transition: opacity .25s ease;
  z-index: 0;
  mix-blend-mode: overlay;
}
.feature-card:hover { transform: translateY(-6px); border-color: var(--border-2); box-shadow: var(--shadow); }
.feature-card > * { position: relative; z-index: 1; }
.f-icon {
  font-size: 2rem;
  width: 56px; height: 56px;
  display: flex; align-items: center; justify-content: center;
  background: var(--bg-3);
  border: 1px solid var(--border-2);
  border-radius: 14px;
  margin-bottom: 18px;
}
.feature-card h3 { font-size: 1.15rem; margin-bottom: 10px; letter-spacing: -.01em; }
.feature-card p { color: var(--text-dim); font-size: .94rem; }

/* ---------- Use cases ---------- */
.usecase-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}
.usecase {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px 28px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  position: relative;
  transition: transform .2s ease, border-color .2s ease;
}
.usecase:hover { transform: translateY(-4px); border-color: var(--brand); }
.uc-num {
  font-family: var(--mono);
  font-size: 1.6rem;
  font-weight: 700;
  color: transparent;
  -webkit-text-stroke: 1px var(--border-2);
  letter-spacing: .04em;
}
.usecase h3 { font-size: 1.2rem; }
.usecase p { color: var(--text-dim); font-size: .96rem; }

/* ---------- Split (consistency) ---------- */
.split {
  display: grid;
  grid-template-columns: 1.1fr .9fr;
  gap: 56px;
  align-items: center;
}
.split-text h2 {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -.02em;
  margin-bottom: 18px;
}
.split-text > p { color: var(--text-dim); font-size: 1.05rem; margin-bottom: 22px; }
.split-text strong { color: var(--text); }
.check-list { list-style: none; display: flex; flex-direction: column; gap: 14px; }
.check-list li {
  position: relative;
  padding-left: 32px;
  color: var(--text-dim);
  font-size: .98rem;
}
.check-list li::before {
  content: '✓';
  position: absolute;
  left: 0; top: 0;
  width: 22px; height: 22px;
  display: flex; align-items: center; justify-content: center;
  background: var(--bg-3);
  border: 1px solid var(--accent);
  color: var(--accent);
  border-radius: 50%;
  font-size: .72rem;
  font-weight: 700;
}
.check-list strong { color: var(--text); }

/* cluster diagram */
.split-visual { display: flex; justify-content: center; }
.cluster-diagram {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px 32px;
  width: 100%;
  max-width: 380px;
  text-align: center;
  position: relative;
}
.node {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  background: var(--surface-2);
  border: 1px solid var(--border-2);
  border-radius: 14px;
  padding: 18px 26px;
  position: relative;
}
.node-tag { font-size: .68rem; font-weight: 700; letter-spacing: .1em; color: var(--text-mute); }
.node-dot { width: 14px; height: 14px; border-radius: 50%; background: var(--text-mute); }
.node.leader { border-color: var(--brand); box-shadow: 0 0 0 4px rgba(108,140,255,.12); margin-bottom: 36px; }
.node.leader .node-tag { color: var(--brand); }
.node.leader .node-dot { background: var(--brand); box-shadow: 0 0 14px var(--brand); animation: pulse 2s infinite; }
.node-row { display: flex; gap: 18px; justify-content: center; }
.node.follower .node-dot { background: var(--accent); }
.diagram-caption { margin-top: 28px; font-size: .82rem; color: var(--text-mute); }
@keyframes pulse {
  0%,100% { opacity: 1; }
  50% { opacity: .4; }
}
/* connector lines */
.node.leader::after {
  content: '';
  position: absolute;
  bottom: -36px; left: 50%;
  width: 2px; height: 36px;
  background: linear-gradient(var(--brand), transparent);
  transform: translateX(-50%);
}

/* ---------- Deep dives ---------- */
.deep-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.deep {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color .2s ease;
}
.deep:hover { border-color: var(--border-2); }
.deep summary {
  cursor: pointer;
  padding: 22px 24px;
  font-weight: 600;
  font-size: 1.05rem;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.deep summary::-webkit-details-marker { display: none; }
.deep summary::after {
  content: '+';
  font-size: 1.4rem;
  font-weight: 400;
  color: var(--brand);
  transition: transform .25s ease;
}
.deep[open] summary::after { transform: rotate(45deg); }
.deep-body { padding: 0 24px 24px; }
.deep-body p { color: var(--text-dim); font-size: .94rem; margin-bottom: 12px; }
.deep-body p:last-child { margin-bottom: 0; }
.road-list { list-style: none; display: flex; flex-direction: column; gap: 10px; }
.road-list li {
  color: var(--text-dim);
  font-size: .94rem;
  padding-left: 24px;
  position: relative;
}
.road-list li::before {
  content: '→';
  position: absolute; left: 0;
  color: var(--accent-2);
  font-weight: 700;
}

/* ---------- FAQ ---------- */
.faq-list { display: flex; flex-direction: column; gap: 12px; }
.faq {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}
.faq summary {
  cursor: pointer;
  padding: 20px 22px;
  font-weight: 600;
  font-size: 1.02rem;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: '⌄';
  font-size: 1.2rem;
  color: var(--brand);
  transition: transform .25s ease;
}
.faq[open] summary::after { transform: rotate(180deg); }
.faq p { padding: 0 22px 20px; color: var(--text-dim); font-size: .96rem; }

/* ---------- CTA ---------- */
.cta-final {
  text-align: center;
  padding: 100px 24px;
  position: relative;
  background: radial-gradient(circle at 50% 120%, rgba(108,140,255,.22), transparent 60%);
}
.cta-final h2 {
  font-size: clamp(1.9rem, 5vw, 3rem);
  font-weight: 800;
  letter-spacing: -.02em;
  margin-bottom: 16px;
}
.cta-final p { color: var(--text-dim); font-size: 1.1rem; margin-bottom: 32px; }

/* ---------- Footer ---------- */
.footer { border-top: 1px solid var(--border); background: var(--bg-2); padding: 50px 0 40px; }
.footer-inner { display: flex; flex-direction: column; align-items: center; gap: 18px; text-align: center; }
.footer-brand { display: flex; align-items: center; gap: 9px; font-weight: 800; font-size: 1.15rem; }
.footer-note { color: var(--text-mute); font-size: .88rem; max-width: 560px; }
.footer-links { display: flex; gap: 26px; flex-wrap: wrap; justify-content: center; }
.footer-links a { color: var(--text-dim); font-size: .9rem; transition: color .2s ease; }
.footer-links a:hover { color: var(--brand); }

/* ---------- Reveal animation ---------- */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 980px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .vs-grid { grid-template-columns: 1fr; }
  .deep-grid { grid-template-columns: 1fr; }
  .split { grid-template-columns: 1fr; gap: 40px; }
  .split-visual { order: -1; }
}

@media (max-width: 760px) {
  .nav-links {
    position: fixed;
    top: 61px; left: 0; right: 0;
    flex-direction: column;
    gap: 0;
    background: rgba(12,14,22,.98);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--border);
    padding: 8px 0;
    transform: translateY(-12px);
    opacity: 0;
    pointer-events: none;
    transition: transform .25s ease, opacity .25s ease;
    margin: 0;
  }
  .nav-links.open { transform: none; opacity: 1; pointer-events: auto; }
  .nav-links a {
    padding: 14px 24px;
    width: 100%;
    border-bottom: 1px solid var(--border);
  }
  .nav-links a:last-child { border-bottom: none; }
  .nav-links a::after { display: none; }
  .nav-burger { display: flex; }
  .gh-link span { display: none; }
  .gh-link { padding: 9px; }

  .hero { padding: 70px 0 60px; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
  .feature-grid { grid-template-columns: 1fr; }
  .usecase-grid { grid-template-columns: 1fr; }
  .section { padding: 64px 0; }
  .hero-cta { flex-direction: column; align-items: stretch; }
  .hero-cta .btn { justify-content: center; }
}

@media (max-width: 420px) {
  .container { padding: 0 18px; }
  .hero-stats { grid-template-columns: 1fr 1fr; gap: 12px; }
  .stat { padding: 18px 10px; }
  .brand-text { font-size: 1.05rem; }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
  .reveal { opacity: 1; transform: none; }
}