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

:root {
  --accent: #df002f;
  --accent-dark: #b20025;
  --ink: #252525;
  --muted: #5c5f6b;
  --line: #e3e5ea;
  --bg-soft: #f5f5f5;
}

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink);
  background: #fff;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
a:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.container { max-width: 980px; margin: 0 auto; padding: 0 1.25rem; }

/* Language switch: PT is the default; JS sets data-lang on <html>. */
html[data-lang="en"] [lang="pt"],
html[data-lang="pt"] [lang="en"] { display: none; }

/* Top bar */
.topbar { border-bottom: 1px solid var(--line); background: #fff; position: sticky; top: 0; z-index: 10; }
.topbar .container { display: flex; align-items: center; justify-content: space-between; gap: 1rem; min-height: 56px; }
.topbar nav { display: flex; align-items: center; gap: 1.25rem; font-size: .92rem; flex-wrap: wrap; }
.topbar nav a { color: var(--ink); }
.topbar nav a:hover { color: var(--accent); text-decoration: none; }
.brand { display: inline-flex; align-items: center; padding: .4rem 0; }
.brand img { display: block; height: 48px; width: auto; }

.lang-switch { display: inline-flex; border: 1px solid var(--line); border-radius: 6px; overflow: hidden; }
.lang-switch button {
  font: inherit; font-size: .8rem; font-weight: 600;
  padding: .2rem .6rem; border: 0; background: #fff; color: var(--muted); cursor: pointer;
}
.lang-switch button[aria-pressed="true"] { background: var(--accent); color: #fff; }

/* Hero */
.hero { background: var(--bg-soft); border-bottom: 1px solid var(--line); padding: 3rem 0 2.75rem; }
.eyebrow { font-size: .8rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--accent); margin-bottom: .4rem; }
.hero h1 { font-size: 2rem; line-height: 1.2; margin-bottom: .8rem; }
.hero p { color: var(--muted); max-width: 60ch; margin-bottom: 1.2rem; }

.btn-row { display: flex; flex-wrap: wrap; gap: .5rem; }
.btn {
  display: inline-block; padding: .4rem 1rem; border-radius: 6px;
  border: 1px solid var(--accent); font-size: .88rem; font-weight: 600;
  color: var(--accent); background: #fff;
}
.btn:hover { background: var(--accent); color: #fff; text-decoration: none; }
.btn-solid { background: var(--accent); color: #fff; }
.btn-solid:hover { background: var(--accent-dark); border-color: var(--accent-dark); }

/* Sections */
section { padding: 3rem 0; }
section h2 { font-size: 1.4rem; margin-bottom: .4rem; padding-bottom: .5rem; border-bottom: 2px solid var(--accent); display: inline-block; }
.section-intro { color: var(--muted); margin: .8rem 0 1.75rem; max-width: 70ch; }

/* Project cards */
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(290px, 1fr)); gap: 1.25rem; }
.card {
  display: flex; flex-direction: column; gap: .6rem;
  border: 1px solid var(--line); border-radius: 10px; padding: 1.25rem; background: #fff;
  transition: box-shadow .15s, border-color .15s;
}
.card:hover { box-shadow: 0 4px 18px rgba(26, 26, 46, .08); border-color: #cfd2da; }
.card h3 { font-size: 1.05rem; line-height: 1.35; }
.card h3 a { color: var(--ink); }
.card h3 a:hover { color: var(--accent); text-decoration: none; }
.card p { font-size: .92rem; color: var(--muted); flex: 1; }
.card p.authors { flex: none; font-size: .85rem; color: var(--ink); }
.meta { display: flex; flex-wrap: wrap; align-items: center; gap: .4rem; }
.tag {
  font-size: .72rem; font-weight: 700; letter-spacing: .03em;
  padding: .12rem .55rem; border-radius: 999px; background: #fbeaec; color: var(--accent-dark);
}
.tag-year { background: var(--bg-soft); color: var(--muted); }
.status { font-size: .72rem; font-weight: 700; padding: .12rem .55rem; border-radius: 999px; border: 1px solid var(--line); color: var(--ink); }
.links { display: flex; flex-wrap: wrap; gap: .4rem 1rem; font-size: .88rem; font-weight: 600; padding-top: .4rem; border-top: 1px solid var(--line); }

footer { border-top: 1px solid var(--line); padding: 1.5rem 0 2rem; font-size: .82rem; color: var(--muted); }

@media (max-width: 720px) {
  .hero h1 { font-size: 1.6rem; }
}