/* Arx Systema portfolio — mobile first */
:root {
  --blue: #1F3D7A;
  --blue-dark: #162c58;
  --yellow: #E8A820;
  --yellow-dark: #c98f12;
  --ink: #1b2233;
  --muted: #566075;
  --bg: #f6f7fa;
  --card: #ffffff;
  --line: #dde2ec;
  --radius: 14px;
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 4.5rem; }
body { margin: 0; font-family: var(--font); color: var(--ink); background: var(--bg); line-height: 1.6; -webkit-text-size-adjust: 100%; }
img { max-width: 100%; height: auto; }
a { color: var(--blue); }
a:hover { color: var(--blue-dark); }
:focus-visible { outline: 3px solid var(--yellow); outline-offset: 2px; }

.wrap { width: 100%; max-width: 72rem; margin-inline: auto; padding-inline: 1.25rem; }
.skip { position: absolute; left: -999px; top: 0; background: var(--yellow); color: var(--blue-dark); padding: .6rem 1rem; z-index: 100; }
.skip:focus { left: 0; }

/* Header */
.site-header { position: sticky; top: 0; z-index: 50; background: var(--blue); color: #fff; box-shadow: 0 1px 0 rgba(255,255,255,.08); }
.bar { display: flex; align-items: center; justify-content: space-between; min-height: 3.5rem; flex-wrap: wrap; }
.brand { display: inline-flex; align-items: center; gap: .6rem; color: #fff; text-decoration: none; font-weight: 700; letter-spacing: .02em; }
.nav-toggle { background: transparent; color: #fff; border: 1px solid rgba(255,255,255,.45); border-radius: 8px; padding: .4rem .9rem; font: inherit; cursor: pointer; }
.nav { display: none; width: 100%; flex-direction: column; padding-block: .5rem 1rem; }
.nav.open { display: flex; }
.nav a { color: #fff; text-decoration: none; padding: .6rem 0; border-top: 1px solid rgba(255,255,255,.12); }
.nav a:hover { color: var(--yellow); }

/* Hero */
.hero { background: linear-gradient(160deg, var(--blue) 0%, var(--blue-dark) 100%); color: #fff; padding-block: 3.5rem 4rem; }
.eyebrow { margin: 0 0 .75rem; color: var(--yellow); font-weight: 700; text-transform: uppercase; letter-spacing: .12em; font-size: .8rem; }
.hero h1 { margin: 0 0 1rem; font-size: clamp(1.9rem, 6vw, 3rem); line-height: 1.15; max-width: 22ch; }
.lead { margin: 0 0 1.75rem; max-width: 46rem; font-size: 1.1rem; color: #e4e9f5; }

/* Buttons */
.actions { display: flex; flex-wrap: wrap; gap: .75rem; margin: 0; }
.btn { display: inline-block; padding: .75rem 1.25rem; border-radius: 10px; font-weight: 600; text-decoration: none; border: 2px solid transparent; }
.btn-primary { background: var(--yellow); color: var(--blue-dark); }
.btn-primary:hover { background: var(--yellow-dark); color: var(--blue-dark); }
.btn-ghost { border-color: rgba(255,255,255,.55); color: #fff; }
.btn-ghost:hover { background: rgba(255,255,255,.12); color: #fff; }
.btn-outline { border-color: var(--blue); color: var(--blue); }
.btn-outline:hover { background: var(--blue); color: #fff; }

/* Sections */
.section { padding-block: 3.5rem; }
.section h2 { margin: 0 0 .5rem; font-size: 1.7rem; color: var(--blue); }
.section h2::after { content: ""; display: block; width: 3rem; height: 4px; margin-top: .5rem; background: var(--yellow); border-radius: 2px; }
.section-intro { margin: 1rem 0 2rem; color: var(--muted); max-width: 46rem; }

/* Cards */
.cards { display: grid; gap: 1.5rem; }
.card { background: var(--card); border: 1px solid var(--line); border-top: 4px solid var(--blue); border-radius: var(--radius); padding: 1.5rem; display: flex; flex-direction: column; }
.card h3 { margin: 0; font-size: 1.3rem; color: var(--blue); }
.tag { margin: .2rem 0 1rem; color: var(--muted); font-size: .9rem; }
.card dl { margin: 0; }
.card dt { margin-top: .9rem; font-size: .75rem; font-weight: 700; text-transform: uppercase; letter-spacing: .08em; color: var(--blue); }
.card dd { margin: .15rem 0 0; }
.chips { list-style: none; padding: 0; margin: .25rem 0 0; display: flex; flex-wrap: wrap; gap: .4rem; }
.chips li { background: #eef1f8; color: var(--blue-dark); border-radius: 999px; padding: .15rem .7rem; font-size: .85rem; }
.cite { margin: 1.25rem 0 0; padding: .75rem 1rem; background: #fff8e6; border-left: 4px solid var(--yellow); border-radius: 6px; font-size: .92rem; }
.cite p { margin: 0; font-style: italic; }
.cite footer { margin-top: .25rem; font-size: .8rem; color: var(--muted); }
.links { display: flex; flex-wrap: wrap; gap: 1rem; margin: auto 0 0; padding-top: 1.25rem; font-weight: 600; }

/* Tools */
.section-dark { background: var(--blue); color: #fff; }
.section-dark h2 { color: #fff; }
.section-dark .section-intro { color: #d3dbee; }
.section-dark a { color: var(--yellow); }
.section-dark a:hover { color: #fff; }
.tools { display: grid; gap: 1.5rem; }
.tool { background: rgba(255,255,255,.07); border: 1px solid rgba(255,255,255,.18); border-radius: var(--radius); padding: 1.5rem; }
.tool h3 { margin: 0 0 .5rem; color: var(--yellow); font-size: 1.2rem; }
.tool p { margin: 0 0 .75rem; }
.meta { font-size: .85rem; color: #c3cde6; }
.tool .links { padding-top: .25rem; margin-top: 0; }

/* Contact & footer */
.contact { text-align: center; }
.contact h2::after { margin-inline: auto; }
.contact .actions { justify-content: center; margin-top: 1.5rem; }
.site-footer { background: var(--blue-dark); color: #d3dbee; padding-block: 1.75rem; font-size: .9rem; }
.site-footer p { margin: .2rem 0; }
.site-footer a { color: #fff; }

/* Tablet and up */
@media (min-width: 48rem) {
  .nav-toggle { display: none; }
  .nav, .nav.open { display: flex; flex-direction: row; width: auto; gap: 1.75rem; padding: 0; }
  .nav a { border-top: 0; padding: 0; }
  .hero { padding-block: 5.5rem 6rem; }
  .cards { grid-template-columns: repeat(2, 1fr); }
  .tools { grid-template-columns: repeat(3, 1fr); }
  .section { padding-block: 5rem; }
}

@media (min-width: 70rem) {
  .cards { grid-template-columns: repeat(3, 1fr); }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}