/* ============================================================
   global.css — Antarctica Expedition Zodiac Landing
   1. Custom properties
   2. Reset & base
   3. Layout
   4. Header
   5. Footer
   6. Typography utilities
   7. Buttons
   8. Responsive (mobile-first → 768px)
   ============================================================ */

/* 1. Custom Properties */
:root {
  --color-navy:      #0a1628;
  --color-navy-mid:  #112240;
  --color-navy-light:#1a3456;
  --color-ice:       #f0f6fc;
  --color-ice-dark:  #e2edf8;
  --color-white:     #ffffff;
  --color-orange:    #e8520a;
  --color-orange-h:  #c94509;
  --color-text:      #1a2b3d;
  --color-muted:     #536b84;
  --color-border:    #d1dce8;
  --color-gold:      #f5c518;
  --color-silver:    #9eb0bf;
  --color-bronze:    #cd8b4a;
  --max-width:       860px;
  --radius:          6px;
  --radius-lg:       10px;
  --shadow:          0 2px 12px rgba(10,22,40,.10), 0 1px 3px rgba(10,22,40,.06);
  --shadow-md:       0 4px 20px rgba(10,22,40,.14), 0 2px 6px rgba(10,22,40,.08);
  --font:            -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --header-h:        60px;
}

/* 2. Reset & Base */
*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-white);
  margin: 0;
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: var(--color-orange);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

p { margin: 0 0 1rem; }
p:last-child { margin-bottom: 0; }

ul, ol { padding-left: 1.5rem; margin: 0 0 1rem; }

h1, h2, h3, h4 {
  margin: 0 0 1rem;
  line-height: 1.25;
  font-weight: 700;
  color: var(--color-navy);
}

h1 { font-size: 1.85rem; font-weight: 800; letter-spacing: -0.02em; }
h2 { font-size: 1.45rem; letter-spacing: -0.01em; }
h3 { font-size: 1.15rem; }
h4 { font-size: 1rem; }

/* 3. Layout */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.25rem;
}

.section {
  padding: 3rem 0;
}

.section--dark {
  background: var(--color-navy);
  color: var(--color-ice);
}

.section--dark h2,
.section--dark h3 {
  color: var(--color-white);
}

.section--ice {
  background: var(--color-ice);
}

/* 4. Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-navy);
  border-bottom: 1px solid var(--color-navy-mid);
  height: var(--header-h);
}

.site-header .container {
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.site-logo {
  display: flex;
  align-items: center;
  flex-shrink: 0;
  text-decoration: none;
}

.site-logo__img {
  height: 36px;
  width: auto;
  display: block;
  filter: brightness(0) invert(1);
}

.site-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: none;
  flex-direction: column;
  gap: 0;
  position: fixed;
  top: var(--header-h);
  left: 0;
  right: 0;
  background: var(--color-navy);
  border-bottom: 1px solid var(--color-navy-mid);
  padding: .75rem 0;
}

.site-nav.is-open ul {
  display: flex;
}

.site-nav a {
  display: block;
  padding: .65rem 1.25rem;
  color: rgba(255,255,255,.8);
  font-size: .9rem;
  font-weight: 500;
  text-decoration: none;
  transition: color .15s;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--color-orange);
  text-decoration: none;
}

.site-nav a.active {
  font-weight: 600;
}

.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  flex-shrink: 0;
}

.nav-toggle span {
  display: block;
  height: 2px;
  background: rgba(255,255,255,.85);
  border-radius: 2px;
  transition: transform .2s, opacity .2s;
}

.nav-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* 5. Footer */
.site-footer {
  background: var(--color-navy);
  color: rgba(255,255,255,.7);
  padding: 2.5rem 0 2rem;
}

.footer__grid {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.footer__tagline {
  font-size: .8rem;
  color: rgba(255,255,255,.45);
  margin-top: .4rem;
  margin-bottom: 0;
  letter-spacing: .04em;
  text-transform: uppercase;
  font-size: .7rem;
}

.footer__links {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem 1.5rem;
}

.footer__links a {
  color: rgba(255,255,255,.65);
  font-size: .875rem;
  text-decoration: none;
  transition: color .15s;
}

.footer__links a:hover {
  color: var(--color-orange);
  text-decoration: none;
}

.footer__copy {
  font-size: .8rem;
  color: rgba(255,255,255,.4);
  border-top: 1px solid rgba(255,255,255,.1);
  padding-top: 1.25rem;
  margin: 0;
}

/* 6. Typography utilities */
.section-label {
  display: block;
  font-size: .7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .12em;
  color: var(--color-orange);
  margin-bottom: .5rem;
}

.lead {
  font-size: 1.1rem;
  line-height: 1.65;
  color: var(--color-muted);
}

.text-muted { color: var(--color-muted); }

.callout {
  background: var(--color-ice);
  border-left: 3px solid var(--color-orange);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0;
}

.callout strong,
.callout h4 {
  color: var(--color-navy);
  font-size: .95rem;
  margin-bottom: .5rem;
}

.callout--dark {
  background: var(--color-navy-mid);
  border-left-color: var(--color-orange);
  color: rgba(255,255,255,.85);
}

.callout--dark strong,
.callout--dark h4 {
  color: var(--color-white);
}

/* 7. Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: .75rem 1.75rem;
  border-radius: var(--radius);
  font-size: .95rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  border: 2px solid transparent;
  transition: background .15s, color .15s, border-color .15s, transform .1s;
  line-height: 1;
}

.btn--orange {
  background: var(--color-orange);
  color: var(--color-white);
  border-color: var(--color-orange);
}

.btn--orange:hover {
  background: var(--color-orange-h);
  border-color: var(--color-orange-h);
  color: var(--color-white);
  text-decoration: none;
  transform: translateY(-1px);
}

.btn--outline {
  background: transparent;
  color: var(--color-orange);
  border-color: var(--color-orange);
}

.btn--outline:hover {
  background: var(--color-orange);
  color: var(--color-white);
  text-decoration: none;
}

/* 8. Responsive — Desktop at 768px */
@media (min-width: 768px) {
  h1 { font-size: 2.4rem; }
  h2 { font-size: 1.75rem; }
  h3 { font-size: 1.2rem; }

  .section { padding: 4rem 0; }

  /* Header desktop */
  .nav-toggle { display: none; }

  .site-nav ul {
    display: flex;
    flex-direction: row;
    position: static;
    background: none;
    border: none;
    padding: 0;
    gap: .25rem;
  }

  .site-nav a {
    padding: .4rem .7rem;
    border-radius: var(--radius);
    font-size: .875rem;
  }

  .site-nav a:hover {
    background: rgba(255,255,255,.08);
  }

  /* Footer desktop */
  .footer__grid {
    flex-direction: row;
    justify-content: space-between;
    align-items: flex-start;
  }
}