*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --navy:    #0A1628; --surface: #0F2040; --elevated: #162847;
  --dim:     #1E3A5F; --bright:  #2E5C8A;
  --cyan:    #00D4FF; --pri: #E8F4FD; --sec: #7BA7C4; --muted: #4A6A85;
  --green:   #00C896; --amber: #F59E0B; --red: #EF4444;
  --l0: #EF4444; --l1: #F97316; --l2: #F59E0B; --l3: #00D4FF; --l4: #00C896;
}
html { scroll-behavior: smooth; }
body { background: var(--navy); color: var(--pri); font-family: 'Inter', system-ui, sans-serif; line-height: 1.6; -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
/* NAV */
#nav { position: fixed; top: 0; left: 0; right: 0; z-index: 100; height: 56px; background: rgba(10,22,40,0.96); backdrop-filter: blur(12px); border-bottom: 1px solid var(--dim); display: flex; align-items: center; justify-content: space-between; padding: 0 32px; gap: 20px; }
.nav-logo { display: flex; align-items: center; gap: 10px; white-space: nowrap; }
.nav-logo-mark { font-size: 16px; color: var(--cyan); font-weight: 800; }
.nav-logo-text { font-size: 11px; color: var(--muted); font-weight: 500; letter-spacing: 0.03em; }
.nav-links { display: flex; gap: 24px; align-items: center; flex: 1; justify-content: center; }
.nav-links a { font-size: 13px; color: var(--sec); font-weight: 500; transition: color .15s; padding: 4px 0; border-bottom: 2px solid transparent; }
.nav-links a:hover, .nav-links a.active { color: var(--pri); border-bottom-color: var(--cyan); }
.nav-right { display: flex; align-items: center; gap: 14px; white-space: nowrap; }
.nav-atom { font-size: 12px; color: var(--muted); }
.nav-atom:hover { color: var(--sec); }
.btn-nav { background: var(--cyan); color: #0A1628; font-weight: 700; font-size: 12px; padding: 7px 16px; border-radius: 6px; transition: opacity .15s; }
.btn-nav:hover { opacity: .85; }
/* LAYOUT */
.page-body { padding-top: 56px; }
section { padding: 88px 24px; }
.section-alt { background: var(--surface); }
.container { max-width: 1100px; margin: 0 auto; }
.kicker { font-size: 10px; font-weight: 700; letter-spacing: 0.16em; color: var(--cyan); text-transform: uppercase; margin-bottom: 12px; }
.section-h2 { font-size: clamp(28px, 4.5vw, 48px); font-weight: 800; color: var(--pri); letter-spacing: -0.025em; line-height: 1.1; margin-bottom: 16px; }
.section-lead { font-size: 16px; color: var(--sec); line-height: 1.75; max-width: 700px; }
/* BUTTONS */
.btn-primary { display: inline-block; background: var(--cyan); color: #0A1628; font-weight: 700; font-size: 14px; padding: 13px 28px; border-radius: 8px; transition: opacity .15s; }
.btn-primary:hover { opacity: .87; }
.btn-secondary { display: inline-block; background: transparent; color: var(--pri); font-weight: 600; font-size: 14px; padding: 12px 28px; border-radius: 8px; border: 1px solid var(--dim); transition: border-color .15s, background .15s; }
.btn-secondary:hover { border-color: var(--bright); background: var(--elevated); }
.btn-ghost { display: inline-block; font-size: 13px; color: var(--cyan); font-weight: 600; }
.btn-ghost:hover { text-decoration: underline; }
/* CARDS */
.card { background: var(--elevated); border: 1px solid var(--dim); border-radius: 12px; padding: 24px; }
.card-hover { transition: border-color .15s; }
.card-hover:hover { border-color: var(--bright); }
/* LEVEL BADGES */
.level-pill { display: inline-block; padding: 3px 10px; border-radius: 12px; font-weight: 700; font-size: 11px; letter-spacing: 0.04em; }
.lp-0 { background: rgba(239,68,68,.15); color: #EF4444; }
.lp-1 { background: rgba(249,115,22,.15); color: #F97316; }
.lp-2 { background: rgba(245,158,11,.15); color: #F59E0B; }
.lp-3 { background: rgba(0,212,255,.12); color: #00D4FF; }
.lp-4 { background: rgba(0,200,150,.12); color: #00C896; }
/* CODE */
pre, code { font-family: 'JetBrains Mono', 'Fira Mono', monospace; }
.code-block { background: var(--navy); border: 1px solid var(--dim); border-radius: 8px; padding: 20px 24px; overflow-x: auto; }
.code-block code { font-size: 13px; color: var(--sec); line-height: 1.7; }
/* TABLES */
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: 13px; }
th { padding: 10px 14px; font-size: 10px; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); border-bottom: 1px solid var(--dim); text-align: left; }
td { padding: 13px 14px; border-bottom: 1px solid rgba(30,58,95,0.4); color: var(--sec); }
tr:hover td { background: var(--elevated); }
.mono { font-family: 'JetBrains Mono', monospace; }
/* FOOTER */
footer { background: var(--surface); border-top: 1px solid var(--dim); padding: 56px 32px 32px; }
.footer-grid { max-width: 1100px; margin: 0 auto; display: grid; grid-template-columns: repeat(4, 1fr); gap: 40px; margin-bottom: 40px; }
.footer-col-label { font-size: 10px; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); margin-bottom: 16px; }
.footer-col a { display: block; font-size: 13px; color: var(--sec); margin-bottom: 9px; }
.footer-col a:hover { color: var(--pri); }
.footer-bar { max-width: 1100px; margin: 0 auto; border-top: 1px solid var(--dim); padding-top: 24px; text-align: center; font-size: 12px; color: var(--muted); line-height: 2; }
.footer-bar a { color: var(--muted); }
.footer-bar a:hover { color: var(--sec); }
/* SCROLLBAR */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--navy); }
::-webkit-scrollbar-thumb { background: var(--dim); border-radius: 3px; }
/* RESPONSIVE */
@media (max-width: 768px) {
  #nav { padding: 0 16px; }
  .nav-links { display: none; }
  .nav-logo-text { display: none; }
  section { padding: 64px 16px; }
  .footer-grid { grid-template-columns: repeat(2, 1fr); gap: 28px; }
}
@media (max-width: 480px) {
  .footer-grid { grid-template-columns: 1fr; }
}