/* ========================================================================== 
   GLOBAL DESIGN SYSTEM
   Desktop first · 1rem = 10px
   ========================================================================== */

:root {
  /* Typography
     Two-family system:
     - Georgia = headings / editorial hierarchy
     - Arial/Helvetica = body / UI / navigation */
  --font-heading: Georgia, 'Times New Roman', serif;
  --font-body: Arial, Helvetica, sans-serif;

  /* Backwards-compatible aliases */
  --font-serif: var(--font-heading);
  --font-sans: var(--font-body);

  /* Type scale */
  --text-small: 1.6rem;
  --text-body: 1.8rem;
  --text-card: 2rem;
  --heading-small: 3.2rem;
  --heading-section: 4rem;
  --heading-page: 5.8rem;
  --heading-hero: 6.4rem;

  /* Line heights */
  --line-body: 1.55;
  --line-heading: 1.1;

  /* Colours */
  --color-text: #333333;
  --color-text-soft: #666666;
  --color-white: #ffffff;
  --color-black: #000000;
  --color-contact-bg: #575757;

  /* Layout */
  --site-max-width: 140rem;
  --page-gutter: 4rem;
  --nav-gutter: 6rem;

  /* UI */
  --radius-small: 0.4rem;
  --radius-medium: 1rem;
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
}

/* ========================================================================== 
   RESET
   ========================================================================== */

html {
  font-size: 62.5%;
  box-sizing: border-box;
  scroll-behavior: smooth;
}

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

body {
  min-width: 32rem;
  font-family: var(--font-body);
  font-size: var(--text-body);
  line-height: var(--line-body);
  color: var(--color-text);
  background-color: var(--color-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* All semantic headings share one family.
   Individual pages only control size, weight and spacing. */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-heading);
  line-height: var(--line-heading);
}

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

button,
input,
textarea,
select {
  font: inherit;
}

a {
  color: inherit;
}

/* ========================================================================== 
   SHARED NAVIGATION
   Navigation stays sans-serif because it is interface text, not a heading.
   ========================================================================== */

.main-nav {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1000;
  width: 100%;
  padding: 3rem var(--nav-gutter);

  background: linear-gradient(
    to bottom,
    rgba(0, 0, 0, 1) 0%,
    rgba(0, 0, 0, 0.7) 50%,
    rgba(0, 0, 0, 0) 100%
  );
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: var(--site-max-width);
  margin: 0 auto;
}

.logo {
  color: var(--color-white) !important;
  font-family: var(--font-body);
  font-size: 2.2rem;
  font-weight: 400;
  line-height: 1.2;
  letter-spacing: 0.1rem;
  text-decoration: none;
  text-shadow: 0 0.1rem 0.2rem rgba(0, 0, 0, 0.2);
}

.nav-links {
  display: flex;
  gap: 3.5rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav-links a {
  display: inline-block;
  padding-bottom: 0.5rem;
  color: rgba(255, 255, 255, 0.82) !important;
  font-family: var(--font-body);
  font-size: var(--text-small);
  font-weight: 400;
  line-height: 1.2;
  text-decoration: none;
  text-shadow: 0 0.1rem 0.2rem rgba(0, 0, 0, 0.2);
  border-bottom: 0.1rem solid transparent;
  transition:
    color var(--transition-normal),
    border-color var(--transition-normal);
}

.nav-links a:hover,
.nav-links a.active,
.nav-links a[aria-current='page'] {
  color: var(--color-white) !important;
  border-bottom-color: var(--color-white);
}

.nav-links a:focus-visible,
.logo:focus-visible {
  outline: 0.2rem solid var(--color-white);
  outline-offset: 0.4rem;
}

/* ========================================================================== 
   SHARED BUTTON LANGUAGE
   Buttons are interface elements and therefore use the body/UI family.
   ========================================================================== */

.hero-btn,
.contact__button {
  font-family: var(--font-body);
  font-weight: 400;
  text-decoration: none;
  cursor: pointer;
  transition:
    background-color var(--transition-fast),
    color var(--transition-fast),
    opacity var(--transition-fast),
    border-color var(--transition-fast);
}