/* ── Google Font ─────────────────────────────────────────── */
@import url('https://fonts.googleapis.com/css2?family=Montserrat:wght@400;500&display=swap');
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500&display=swap');

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

html, body {
  height: 100%;
  width: 100%;
  overflow: auto;
}

body {
  font-family: 'Montserrat', sans-serif;
  background-color: #000;
}

/* ── Hero ────────────────────────────────────────────────── */
.hero {
  position: relative;
  width: 100%;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  
  /* ── Center content ──────────────────────────────────────── */
  z-index: 1;
  flex-direction: column;
  gap: calc(var(--logo-gap) * 2); /* half of GRADIBORD height */
}

.hero__bg {
  position: absolute;
  inset: 0;
  background: url('assets/img/background.png') center center / cover no-repeat;
  z-index: -1;
}

.hero__bg::after {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.35);
}

/* ── Logo composition ────────────────────────────────────── */
/*
  Nabla is positioned absolutely to the left of the brand logo.
  It is 2× the height of the brand logo and vertically centred
  on the brand logo's midpoint.
  Both logos share a common CSS custom property for the brand
  logo height so the 2× ratio is always maintained.
*/
:root {
  --brand-h: clamp(50px, 5vw, 110px);
  --logo-gap: calc(var(--brand-h) * 0.5);   /* half of GRADIBORD height */
  --btn-fs:   calc(var(--brand-h) * 0.2);  /* button font scales with logo */
  --caption-fs: calc(var(--brand-h) * 0.16); /* caption font scales with logo */
}

.logo-group {
  position: relative;     /* anchor for absolutely-positioned nabla */
  z-index: 1;
  display: inline-flex;   /* shrink-wrap to brand-logo width only */
  align-items: center;
}

/* Nabla is pulled out of the centered flow and floats to the left */
.nabla {
  position: absolute;
  right: 100%;
  margin-right: clamp(1rem, 2.5vw, 2rem);  /* mirrors the original gap */
  top: 50%;
  transform: translateY(-50%);
}

.nabla img {
  height: calc(var(--brand-h) * 2);
  width: auto;
  display: block;
}

.brand-logo img {
  height: var(--brand-h);
  width: auto;
  display: block;
}

/* ── Navigation buttons ──────────────────────────────── */
.nav-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: clamp(0.75rem, 4vw, 4.5rem);
    justify-content: center;
    align-items: flex-start; /* align multiple nav-items consistently */
}

/* Group each button with its caption */
.nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.35rem;
}

.nav-btn {
    display: inline-block;
    text-decoration: none;
    text-align: center;           /* always centre the label */
    color: #fff;
    letter-spacing: 0.18em;
    font-size: var(--btn-fs);
    font-weight: 500;
    text-transform: uppercase;
    padding: 0.65em 2em;
    border: 1.5px solid rgba(255, 255, 255, 0.75);
    background: rgba(255, 255, 255, 0.06);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    cursor: pointer;
    transition: background 0.25s ease, border-color 0.25s ease, color 0.25s ease;
    white-space: nowrap;
}

.nav-btn:hover,
.nav-btn:focus-visible {
  background: rgba(255, 255, 255, 0.8);
  border-color: #3a3a3a;
  color: #3a3a3a;
  outline: none;
}

/* ── "In Development" caption ────────────────────────────── */
.btn-caption {
  font-family: 'Montserrat', sans-serif;
  font-weight: 400;                /* Regular */
  font-size: var(--caption-fs);
  color: #D97925;
  letter-spacing: 0.08em;
  text-align: center;
  margin: 0; /* spacing controlled by .nav-item gap */
}

/* ── Footer ─────────────────────────────────────────────── */
footer {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1;
  padding: 2rem;
  text-align: center;
  color: #d4d4d4;
  font-size: 0.9rem;
}

/* ── Stacked logo: nabla moves above GRADIBORD when it would clip (≤ 768 px) ── */
@media (max-width: 768px) {
  :root {
    --brand-h: clamp(40px, 10vw, 80px);
    --logo-gap:    calc(var(--brand-h) * 0.5);
    --btn-fs:      calc(var(--brand-h) * 0.18);
    --caption-fs:  calc(var(--brand-h) * 0.13);
  }

  /* Nabla re-enters the flow and sits above GRADIBORD */
  .nabla {
    position: static;
    transform: none;
    margin-right: 0;
  }

  .logo-group {
    flex-direction: column;
    align-items: center;
    gap: var(--logo-gap);
  }
}

/* ── Mobile (≤ 600 px) ───────────────────────────────────── */
@media (max-width: 600px) {

  :root {
    --brand-h:    42px;
    --logo-gap:   calc(var(--brand-h) * 0.5);  /* = 21px */
    --btn-fs:     calc(var(--brand-h) * 0.18); /* ≈ 7.6px – floor below */
    --caption-fs: calc(var(--brand-h) * 0.13); /* ≈ 5.5px – floor below */
  }

  .hero {
    height: auto;
    min-height: 100svh;
    padding: 2.5rem 1.25rem 3rem;
  }

  /* Stack buttons vertically on phone */
  .nav-buttons {
    flex-direction: column;
    align-items: center;
    gap: var(--logo-gap);
  }

  .nav-btn {
    /* minimum readable size on small screens */
    font-size: max(var(--btn-fs), 0.75rem);
    min-width: 10em;
    width: auto;
    max-width: 280px;
    text-align: center;
  }

  .btn-caption {
    font-size: max(var(--caption-fs), 0.6rem);
  }
}

/* ── Sub page ──────────────────────────────────────── */
body.sub-page {
  overflow: auto;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

body.sub-page header {
  text-align: center;
  padding: 2rem;
}

body.sub-page header img {
  max-width: 300px;
  height: auto;
}

body.sub-page main {
  font-family: 'Inter', sans-serif;
  max-width: 800px;
  width: 100%;
  height: fit-content;
  margin: 0 auto;
  padding: 2rem; /* bottom padding keeps last item clear of footer */
  color: #fff;

  /* Glassmorphism-inspired styling */
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(5px);
  -webkit-backdrop-filter: blur(5px);
  border-radius: 20px;
  border: 1px solid rgba(255, 255, 255, 0.3);
  box-shadow: 
    0 8px 32px rgba(0, 0, 0, 0.1),
    inset 0 1px 0 rgba(255, 255, 255, 0.5),
    inset 0 -1px 0 rgba(255, 255, 255, 0.1),
    inset 0 0 0px 0px rgba(255, 255, 255, 0);

}

body.sub-page main h1 {
  text-align: center;
  padding-bottom: 2rem;
  font-size: 1.5em;
  letter-spacing: 0.1em;
  color: #fff;
}

body.sub-page main li {
  margin-bottom: 2rem;
}

body.sub-page main ol {
  margin-bottom: 4rem;
}

body.sub-page main img {
  display: flex;
  margin: 2rem auto 0 auto;
  max-width: 4em;
  height: auto;
}

/* Override the global fixed footer for this page */
body.sub-page footer {
  position: static;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 2rem;
  text-align: center;
  color: #d4d4d4;
  font-size: 0.9rem;

  margin-top: auto; /* push footer to bottom when content is short */
}