/* =========================================================
   CRYPTCS — "Learn and Trade Crypto Like a Pro"
   Custom crypto/fintech design system
   ========================================================= */

:root {
  --bg: #070a12;
  --bg-2: #0c1120;
  --surface: #121a2c;
  --surface-2: #18233a;
  --ink: #e8edf7;
  --muted: #8a94ad;
  --cyan: #22d3ee;
  --cyan-soft: #0c2b33;
  --green: #16c784;
  --red: #ea3943;
  --gold: #f0b90b;
  --blue: #5b8cff;
  --blue-soft: #14233f;
  --border: #1e2740;
  --shadow-lg: 0 30px 80px rgba(0, 0, 0, 0.55);
  --radius: 18px;
  --radius-sm: 12px;
  --font-display: "Space Grotesk", "Segoe UI", system-ui, sans-serif;
  --font-sans: "Inter", "Segoe UI", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "Consolas", monospace;
  --container: 1180px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  color: var(--ink);
  background:
    radial-gradient(900px 520px at 90% -100px, rgba(34, 211, 238, 0.14), transparent 60%),
    radial-gradient(700px 480px at -60px 10%, rgba(91, 140, 255, 0.12), transparent 55%),
    var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul, ol { list-style: none; }

.container { max-width: var(--container); margin: 0 auto; padding: 0 24px; }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(7, 10, 18, 0.82);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 24px; padding: 16px 24px; }
.brand { display: flex; align-items: center; gap: 12px; font-family: var(--font-display); font-weight: 700; font-size: 1.3rem; letter-spacing: 0.01em; }
.brand-mark {
  width: 40px; height: 40px; border-radius: 11px;
  background: linear-gradient(135deg, var(--cyan), var(--blue));
  display: grid; place-items: center; color: #04121a;
  font-weight: 700; font-size: 1.1rem;
}
.brand span.accent { color: var(--cyan); }

.nav-toggle { display: none; background: none; border: none; color: var(--ink); font-size: 1.5rem; cursor: pointer; }
.main-nav ul { display: flex; align-items: center; gap: 4px; }
.main-nav a {
  display: inline-block; padding: 9px 16px; border-radius: 999px;
  font-size: 0.9rem; font-weight: 500; color: var(--muted); transition: 0.2s;
}
.main-nav a:hover, .main-nav a.active { color: var(--ink); background: var(--surface-2); }
.nav-cta { margin-left: 8px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 26px; border-radius: 999px; font-weight: 600; font-size: 0.92rem;
  border: none; cursor: pointer; transition: 0.2s;
}
.btn-primary { background: linear-gradient(135deg, var(--cyan), var(--blue)); color: #04121a; box-shadow: 0 10px 26px rgba(34, 211, 238, 0.25); }
.btn-primary:hover { transform: translateY(-2px); }
.btn-ghost { background: transparent; color: var(--ink); border: 1px solid var(--border); }
.btn-ghost:hover { border-color: var(--cyan); color: var(--cyan); }

/* ---------- Hero ---------- */
.hero { padding: 88px 0 72px; }
.hero .container { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 52px; align-items: center; }
.hero .eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 0.78rem; letter-spacing: 0.16em; text-transform: uppercase; color: var(--cyan);
  margin-bottom: 20px;
}
.hero .eyebrow::before { content: ""; width: 28px; height: 1px; background: var(--cyan); }
.hero h1 {
  font-family: var(--font-display); font-size: clamp(2.4rem, 5.5vw, 4rem);
  line-height: 1.06; font-weight: 700; letter-spacing: -0.02em;
}
.hero h1 em { font-style: normal; color: var(--cyan); }
.hero p.lead { margin: 22px 0 30px; font-size: 1.1rem; color: var(--muted); max-width: 520px; }
.hero .cta-row { display: flex; gap: 14px; flex-wrap: wrap; }
.hero .stats { display: flex; gap: 34px; margin-top: 44px; }
.hero .stat b { display: block; font-family: var(--font-display); font-size: 1.7rem; }
.hero .stat span { font-size: 0.82rem; color: var(--muted); }
.hero-visual {
  position: relative; border-radius: var(--radius); overflow: hidden;
  border: 1px solid var(--border); box-shadow: var(--shadow-lg);
  background: var(--surface);
}
.hero-visual img { width: 100%; aspect-ratio: 4/4.4; object-fit: cover; }

/* ---------- Ticker ---------- */
.ticker-band {
  background: var(--bg-2); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border);
  padding: 28px 0;
}
.ticker-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.ticker-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px; display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.ticker-card .pair { display: flex; align-items: center; gap: 12px; }
.ticker-card .coin {
  width: 42px; height: 42px; border-radius: 50%; display: grid; place-items: center;
  font-family: var(--font-display); font-weight: 700; color: #04121a;
}
.ticker-card .coin.btc { background: var(--gold); }
.ticker-card .coin.eth { background: #8c9fff; }
.ticker-card .coin.sol { background: var(--cyan); }
.ticker-card .sym { font-family: var(--font-display); font-weight: 600; }
.ticker-card .sub { font-size: 0.78rem; color: var(--muted); }
.ticker-card .price { text-align: right; }
.ticker-card .price b { font-family: var(--font-display); font-size: 1.2rem; }
.ticker-card .price .up { color: var(--green); font-size: 0.82rem; }

/* ---------- Section helpers ---------- */
.section { padding: 84px 0; }
.section-head { max-width: 640px; margin-bottom: 46px; }
.section-head .kicker { color: var(--cyan); font-size: 0.78rem; letter-spacing: 0.16em; text-transform: uppercase; margin-bottom: 12px; }
.section-head h2 { font-family: var(--font-display); font-size: clamp(1.9rem, 4vw, 2.8rem); line-height: 1.12; letter-spacing: -0.02em; }
.section-head p { color: var(--muted); margin-top: 14px; }

/* ---------- FAQ ---------- */
.faq-list { display: flex; flex-direction: column; gap: 14px; max-width: 780px; margin: 0 auto; }
.faq-item { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-sm); overflow: hidden; }
.faq-item summary {
  cursor: pointer; padding: 20px 24px; font-weight: 600; font-size: 1rem;
  display: flex; justify-content: space-between; align-items: center; list-style: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: "+"; font-size: 1.4rem; color: var(--cyan); }
.faq-item[open] summary::after { content: "–"; }
.faq-item p { padding: 0 24px 22px; color: var(--muted); font-size: 0.95rem; }

/* ---------- Blog grid ---------- */
.blog-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.post-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  overflow: hidden; transition: 0.25s; display: flex; flex-direction: column;
}
.post-card:hover { transform: translateY(-6px); border-color: var(--cyan); }
.post-card img { aspect-ratio: 16/10; object-fit: cover; }
.post-card .body { padding: 20px 22px 24px; display: flex; flex-direction: column; flex: 1; }
.post-card .tag { font-size: 0.72rem; color: var(--cyan); text-transform: uppercase; letter-spacing: 0.1em; margin-bottom: 8px; }
.post-card h3 { font-family: var(--font-display); font-size: 1.18rem; line-height: 1.3; margin-bottom: 10px; }
.post-card h3 a:hover { color: var(--cyan); }
.post-card p { font-size: 0.9rem; color: var(--muted); flex: 1; }
.post-card .date { font-size: 0.78rem; color: var(--muted); margin-top: 14px; }

/* ---------- CTA band ---------- */
.cta-band {
  background: linear-gradient(120deg, var(--cyan), var(--blue));
  color: #04121a; border-radius: var(--radius); padding: 52px 48px;
  display: flex; align-items: center; justify-content: space-between; gap: 28px; flex-wrap: wrap;
}
.cta-band h2 { font-family: var(--font-display); font-size: clamp(1.6rem, 3.5vw, 2.4rem); line-height: 1.15; }
.cta-band p { opacity: 0.85; margin-top: 8px; }
.cta-band .btn { background: #04121a; color: #fff; }

/* ---------- Page hero (subpages) ---------- */
.page-hero { padding: 72px 0 40px; text-align: center; }
.page-hero .kicker { color: var(--cyan); font-size: 0.78rem; letter-spacing: 0.16em; text-transform: uppercase; margin-bottom: 12px; }
.page-hero h1 { font-family: var(--font-display); font-size: clamp(2.2rem, 5vw, 3.4rem); letter-spacing: -0.02em; }
.page-hero p { max-width: 640px; margin: 18px auto 0; color: var(--muted); font-size: 1.05rem; }

/* ---------- Article layout ---------- */
.article-hero { padding: 56px 24px 8px; text-align: center; }
.article-hero .cat-badge {
  display: inline-block; background: var(--cyan-soft); color: var(--cyan);
  font-size: 0.72rem; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase;
  padding: 5px 14px; border-radius: 999px; margin-bottom: 16px;
}
.article-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 4.5vw, 3rem);
  line-height: 1.15; font-weight: 700; max-width: 820px; margin: 0 auto;
}
.article-hero .meta { margin-top: 18px; font-size: 0.9rem; color: var(--muted); }
.article-hero .meta a { color: var(--cyan); font-weight: 500; }
.article-hero .meta .dot { margin: 0 8px; color: var(--gold); }

.article-featured { max-width: 880px; margin: 28px auto 0; border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-lg); }
.article-featured img { width: 100%; aspect-ratio: 16/9; object-fit: cover; }

/* ---------- Article body (prose) ---------- */
.article-body { max-width: 780px; margin: 0 auto; padding: 44px 24px 24px; }
.article-body h2 {
  font-family: var(--font-display);
  font-size: 1.6rem; font-weight: 700; line-height: 1.25;
  margin: 44px 0 16px; color: var(--ink);
  padding-bottom: 10px; border-bottom: 1px solid var(--border);
}
.article-body h3 {
  font-family: var(--font-display);
  font-size: 1.22rem; font-weight: 600; line-height: 1.3;
  margin: 30px 0 12px; color: var(--ink);
}
.article-body p { margin: 0 0 16px; color: #b8c1d6; }
.article-body p strong { color: var(--ink); }
.article-body ul, .article-body ol { margin: 0 0 16px 22px; color: #b8c1d6; }
.article-body ul { list-style: disc; }
.article-body ol { list-style: decimal; }
.article-body li { margin: 6px 0; }
.article-body li strong { color: var(--ink); }
.article-body figure { margin: 24px 0; border-radius: var(--radius); overflow: hidden; border: 1px solid var(--border); }
.article-body figure img { width: 100%; height: auto; }

/* ---------- Tables ---------- */
.article-body table {
  width: 100%; border-collapse: collapse; margin: 22px 0; font-size: 0.9rem;
  background: var(--surface); border-radius: var(--radius-sm); overflow: hidden;
}
.article-body table th, .article-body table td {
  padding: 12px 14px; border: 1px solid var(--border); text-align: left; vertical-align: top;
}
.article-body table th { background: var(--surface-2); color: var(--ink); font-family: var(--font-display); font-weight: 600; }
.article-body table td { color: #b8c1d6; }
.article-body table td strong { color: var(--ink); }

/* ---------- Author box ---------- */
.author-box { max-width: 780px; margin: 0 auto 44px; padding: 0 24px; }
.author-box .inner {
  display: flex; gap: 18px; align-items: center;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 22px;
}
.author-box .avatar {
  width: 68px; height: 68px; border-radius: 50%;
  background: linear-gradient(135deg, var(--cyan), var(--blue));
  display: grid; place-items: center; color: #04121a;
  font-family: var(--font-display); font-size: 1.5rem; font-weight: 700; flex-shrink: 0;
}
.author-box h4 { font-family: var(--font-display); font-size: 1.15rem; margin-bottom: 4px; }
.author-box p { font-size: 0.88rem; color: var(--muted); }

/* ---------- Prose (static pages) ---------- */
.prose { max-width: 760px; margin: 0 auto; padding: 24px 24px 80px; }
.prose h2 { font-family: var(--font-display); font-size: 1.7rem; margin: 40px 0 14px; }
.prose p { color: var(--muted); margin: 0 0 16px; }
.prose ul { list-style: disc; margin: 0 0 16px 22px; color: var(--muted); }
.prose li { margin: 6px 0; }
.prose a { color: var(--cyan); }

/* ---------- Contact ---------- */
.contact-layout { display: grid; grid-template-columns: 0.9fr 1.1fr; gap: 40px; align-items: start; padding: 24px 0 80px; }
.contact-info { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 32px; }
.contact-info h3 { font-family: var(--font-display); font-size: 1.3rem; margin-bottom: 18px; }
.contact-info .line { margin: 14px 0; color: var(--muted); font-size: 0.95rem; }
.contact-info .line b { color: var(--ink); display: block; font-size: 0.9rem; }
.form-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 32px; }
.form-card label { display: block; font-size: 0.85rem; color: var(--muted); margin: 14px 0 6px; }
.form-card input, .form-card textarea {
  width: 100%; padding: 12px 14px; border-radius: 10px;
  border: 1px solid var(--border); background: var(--bg-2); color: var(--ink);
  font-family: inherit; font-size: 0.95rem;
}
.form-card input:focus, .form-card textarea:focus { outline: 2px solid var(--cyan); border-color: transparent; }
.form-card .btn { margin-top: 20px; width: 100%; justify-content: center; }

/* ---------- Footer ---------- */
.site-footer { border-top: 1px solid var(--border); background: var(--bg-2); margin-top: 40px; }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px; padding: 56px 24px 40px; }
.footer-col h4 { font-family: var(--font-display); font-size: 1rem; margin-bottom: 18px; color: var(--ink); }
.footer-col p { font-size: 0.9rem; color: var(--muted); margin-top: 12px; }
.footer-col ul li { margin: 10px 0; }
.footer-col ul a { font-size: 0.9rem; color: var(--muted); transition: 0.2s; }
.footer-col ul a:hover { color: var(--cyan); }
.footer-bottom { border-top: 1px solid var(--border); padding: 20px 24px; text-align: center; font-size: 0.8rem; color: var(--muted); }

/* ---------- Reveal ---------- */
[data-reveal] { opacity: 0; transform: translateY(22px); transition: opacity 0.6s ease, transform 0.6s ease; }
[data-reveal].revealed { opacity: 1; transform: none; }

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .hero .container { grid-template-columns: 1fr; }
  .hero-visual { max-width: 480px; }
  .ticker-grid { grid-template-columns: 1fr; }
  .blog-grid { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .contact-layout { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .nav-toggle { display: block; }
  .main-nav { position: fixed; inset: 0; background: var(--bg); padding: 84px 28px; transform: translateX(100%); transition: 0.3s; display: none; }
  .main-nav.open { display: block; transform: translateX(0); }
  .main-nav ul { flex-direction: column; align-items: flex-start; gap: 4px; }
  .main-nav a { font-size: 1.05rem; }
  .nav-cta { margin: 12px 0 0; }
  .blog-grid, .footer-grid { grid-template-columns: 1fr; }
  .hero .stats { gap: 24px; flex-wrap: wrap; }
  .cta-band { padding: 36px 28px; }
  .article-body table { font-size: 0.78rem; }
}