/* Shared presentation for the FX introduction series. */
:root{color-scheme:light;--bg:#f4efe4;--panel:#fffaf0;--ink:#1f1b16;--accent:#b4572f;--line:#d7c8ac}
*{box-sizing:border-box}body{margin:0;color:var(--ink);background:radial-gradient(circle at top left,#fff8df,transparent 35%),linear-gradient(160deg,var(--bg),#eadfc9);font:16px/1.85 system-ui,sans-serif}
main{max-width:1100px;margin:auto;padding:40px 20px 64px}.panel{padding:28px;margin:0 0 24px;background:var(--panel);border:1px solid var(--line);border-radius:24px;box-shadow:0 12px 32px #5a3e2810}
h1{font-size:clamp(1.9rem,5vw,3rem);line-height:1.35}h2{line-height:1.5;margin-top:0}h3{margin-bottom:8px}a{color:#85390f}nav{display:flex;flex-wrap:wrap;gap:18px;margin-bottom:24px}
.kicker{color:var(--accent);font-weight:700;letter-spacing:.12em}.formula{font:1.15rem/1.8 monospace;padding:18px;background:#f0e5d4;border-radius:12px}
pre{padding:18px;overflow:auto;background:#201e1a;color:#fff3df;border-radius:12px;font-size:.9rem;line-height:1.65}code{font-family:ui-monospace,monospace}
table{width:100%;border-collapse:collapse}td,th{text-align:left;border-bottom:1px solid var(--line);padding:10px}
iframe{display:block;width:100%;height:780px;border:1px solid var(--line);border-radius:14px;background:white}
.hint{border-left:4px solid var(--accent);padding-left:16px}.steps li{margin-bottom:10px}
@media(max-width:600px){main{padding:20px 10px}.panel{padding:18px;border-radius:16px}iframe{height:720px}}