/* Bitcoin Đà Nẵng - Reusable components */

/* Buttons */
.btn-primary,
.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.85rem 1.5rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 1rem;
  text-decoration: none;
  border: 2px solid transparent;
  transition: var(--transition);
  cursor: pointer;
}

.btn-primary {
  background: var(--color-gold);
  color: var(--color-black);
}
.btn-primary:hover {
  background: var(--color-gold-light);
  box-shadow: var(--shadow-gold);
  transform: translateY(-1px);
}

.btn-outline {
  border-color: var(--color-gold);
  color: var(--color-gold);
  background: transparent;
}
.btn-outline:hover {
  background: rgba(212, 175, 55, 0.08);
  color: var(--color-gold-light);
}

body.theme-light .btn-outline {
  border-color: var(--color-gold-dark);
  color: var(--color-gold-dark);
}
body.theme-light .btn-outline:hover {
  background: rgba(160, 124, 30, 0.08);
}

/* Cards */
.card {
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  transition: var(--transition);
}

body.theme-dark .card {
  background: var(--color-black-card);
  border: 1px solid rgba(212, 175, 55, 0.18);
}

body.theme-light .card {
  background: #fff;
  border: 1px solid var(--color-white-muted);
  box-shadow: 0 2px 12px rgba(0,0,0,0.04);
}

.card--gold-border {
  border: 2px solid var(--color-gold);
}

/* Sections */
.section {
  padding: clamp(3rem, 8vw, 6rem) 0;
}
.section + .section { border-top: 1px solid rgba(212, 175, 55, 0.08); }

/* Navigation */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}
body.theme-dark .nav { background: rgba(13, 13, 13, 0.82); border-bottom: 1px solid rgba(212, 175, 55, 0.1); }
body.theme-light .nav { background: rgba(250, 247, 240, 0.86); border-bottom: 1px solid var(--color-white-muted); }

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem var(--gutter);
  max-width: var(--max-width);
  margin: 0 auto;
}

.nav__logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-display);
  font-size: 1.35rem;
  text-decoration: none;
  color: inherit;
  font-weight: 600;
}
.nav__logo img { width: 36px; height: 36px; }

.nav__links {
  display: flex;
  gap: 1.6rem;
  list-style: none;
  padding: 0;
  margin: 0;
  align-items: center;
}
.nav__links a {
  text-decoration: none;
  font-weight: 500;
  font-size: 0.97rem;
  color: inherit;
  opacity: 0.85;
}
.nav__links a:hover { opacity: 1; color: var(--color-gold); }

.nav__right { display: flex; align-items: center; gap: 1rem; }

/* Language switcher */
.lang-switcher {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: transparent;
}
.lang-switcher button {
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  padding: 4px 8px;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: inherit;
  font-size: 0.85rem;
  opacity: 0.55;
  transition: var(--transition);
}
.lang-switcher button:hover { opacity: 1; }
.lang-switcher button.is-active {
  opacity: 1;
  border-color: var(--color-gold);
}
.lang-switcher .flag {
  width: 22px;
  height: 16px;
  display: inline-block;
  background-size: cover;
  background-position: center;
  border-radius: 2px;
  background-color: rgba(255,255,255,0.08);
}
.lang-switcher .flag--vn { background-image: url('/images/flag-vn.jpg'); }
.lang-switcher .flag--en { background-image: url('/images/flag-en.jpg'); }

/* Hamburger (mobile) */
.nav__toggle {
  display: none;
  background: transparent;
  border: 1px solid currentColor;
  border-radius: var(--radius-sm);
  padding: 0.45rem 0.6rem;
  color: inherit;
}

@media (max-width: 768px) {
  .nav__links {
    position: fixed;
    top: 0; right: 0;
    height: 100vh;
    width: 78vw;
    max-width: 320px;
    flex-direction: column;
    align-items: flex-start;
    padding: 5rem 1.75rem 2rem;
    gap: 1.25rem;
    transform: translateX(100%);
    transition: transform 0.3s ease;
  }
  body.theme-dark .nav__links { background: var(--color-black-soft); }
  body.theme-light .nav__links { background: #fff; }
  .nav__links.is-open { transform: translateX(0); box-shadow: -8px 0 32px rgba(0,0,0,0.25); }
  .nav__toggle { display: inline-flex; }
}

/* Footer */
.footer {
  padding: 3rem var(--gutter) 2rem;
  text-align: center;
  font-size: 0.9rem;
}
body.theme-dark .footer { background: var(--color-black-soft); color: var(--color-text-muted); border-top: 1px solid rgba(212, 175, 55, 0.1); }
body.theme-light .footer { background: var(--color-white-muted); color: #5a4f3a; }

.footer__partners {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem 2rem;
  justify-content: center;
  margin: 1.25rem 0;
}
.footer__partners a { text-decoration: none; font-weight: 600; color: var(--color-gold); }

.footer__small { font-size: 0.8rem; opacity: 0.75; margin-top: 1rem; }

/* Decorative gold rule */
.gold-rule {
  width: 60px; height: 2px;
  background: var(--color-gold);
  border: 0;
  margin: 1rem auto 1.5rem;
}

/* Tag chip */
.chip {
  display: inline-block;
  font-size: 0.8rem;
  padding: 0.25rem 0.65rem;
  border-radius: 999px;
  border: 1px solid var(--color-gold);
  color: var(--color-gold);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* Eyebrow caption - small uppercase gold label above section H2s.
   Used verbatim from the pencil mockups, e.g. "VỀ CHÚNG TÔI / ABOUT US". */
.eyebrow {
  display: inline-block;
  font-family: var(--font-body);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-gold);
  margin-bottom: 0.85rem;
}
body.theme-light .eyebrow { color: var(--color-gold-dark); }

/* Grid helpers */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}
.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}