/* ==========================================================================
   DEEPSPACE — index.html
   Layout : header (menu) / hero (title + download buttons) / footer
   Artwork: img/background.png
   Typeface: Oxanium (self-hosted variable woff2, see fonts/)
   ========================================================================== */

/* ---------- Oxanium webfont (self-hosted, variable 200-800) -------------- */
/* Local files -> no CDN request, no cache/network dependency. */
@font-face {
  font-family: "Oxanium";
  font-style: normal;
  font-weight: 200 800;
  font-display: swap;
  src: url("../fonts/Oxanium-Variable-latin-ext.woff2") format("woff2");
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7,
    U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F,
    U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F,
    U+A720-A7FF;
}

@font-face {
  font-family: "Oxanium";
  font-style: normal;
  font-weight: 200 800;
  font-display: swap;
  src: url("../fonts/Oxanium-Variable-latin.woff2") format("woff2");
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6,
    U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122,
    U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

/* ---------- Design tokens ------------------------------------------------ */
:root {
  color-scheme: dark;

  --font-main: "Oxanium", "Segoe UI", "Helvetica Neue", Arial, sans-serif;

  --color-text: #ffffff;
  --color-text-soft: rgba(255, 255, 255, 0.72);
  --color-text-muted: rgba(255, 255, 255, 0.55);
  --color-line: rgba(255, 255, 255, 0.55);
  --color-accent: #0a5cff;                 /* brand blue (logo_ar.png) */
  --color-accent-glow: rgba(10, 92, 255, 0.55);
  --color-space: #04060f;

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --duration: 220ms;

  --page-pad-x: clamp(1.15rem, 4vw, 4rem);
  --page-pad-y: clamp(1rem, 2.5vw, 2rem);
}

/* ---------- Reset -------------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body,
h1,
h2,
p,
ul {
  margin: 0;
}

ul {
  padding: 0;
  list-style: none;
}

img {
  max-width: 100%;
}

/* ---------- Page shell + background ------------------------------------- */
body {
  position: relative;
  isolation: isolate;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  min-height: 100svh;
  padding: var(--page-pad-y) var(--page-pad-x);
  background-color: var(--color-space);
  color: var(--color-text);
  font-family: var(--font-main);
  font-weight: 400;
  line-height: 1.4;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Background artwork, fixed so it never stretches on tall viewports. */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  background-color: var(--color-space);
  background-image: url("../img/background.png");
  background-repeat: no-repeat;
  background-position: center;
  background-size: cover;
}

/* Legibility overlay: darkens the header/footer edges, adds a vignette and a
   soft centre scrim so the copy stays readable over the bright spacecraft. */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    linear-gradient(180deg, rgba(4, 6, 15, 0.82) 0%, rgba(4, 6, 15, 0) 24%),
    linear-gradient(0deg, rgba(4, 6, 15, 0.78) 0%, rgba(4, 6, 15, 0) 22%),
    radial-gradient(58% 46% at 50% 50%, rgba(4, 6, 15, 0.42) 0%, rgba(4, 6, 15, 0) 72%),
    radial-gradient(125% 95% at 50% 52%, rgba(4, 6, 15, 0) 38%, rgba(4, 6, 15, 0.6) 100%);
}

/* ---------- Menu header -------------------------------------------------- */
/* Text-only menu: the items are centred in the top bar. */
.site-header {
  display: flex;
  justify-content: center;
  align-items: center;
}

.site-header__nav {
  --nav-gap: clamp(0.9rem, 2.2vw, 1.5rem);
  display: flex;
  justify-content: center;
}

.site-header__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: var(--nav-gap);
}

.nav-link {
  display: block;
  color: var(--color-text-soft);
  font-size: clamp(0.8rem, 1.8vw, 0.98rem);
  font-weight: 500;
  letter-spacing: 0.16em;
  text-decoration: none;
  white-space: nowrap;
  text-shadow: 0 1px 12px rgba(0, 0, 0, 0.7);
  transition:
    color var(--duration) var(--ease),
    text-shadow var(--duration) var(--ease);
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--color-text);
  text-shadow:
    0 0 0.6em var(--color-accent-glow),
    0 0 0.22em var(--color-accent),
    0 1px 12px rgba(0, 0, 0, 0.7);
}

.nav-link:focus-visible {
  outline: 2px solid var(--color-text);
  outline-offset: 4px;
}

.nav-link:active {
  color: var(--color-accent);
}

/* ---------- Hero --------------------------------------------------------- */
.hero {
  flex: 1 1 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: clamp(0.85rem, 2.1vh, 1.45rem);
  padding-block: clamp(2.5rem, 8vh, 5rem);
  text-align: center;
}

.hero__title {
  font-size: clamp(2.35rem, 8.5vw, 6.75rem);
  font-weight: 500;
  line-height: 0.95;
  letter-spacing: 0.06em;
  text-indent: 0.06em; /* optically re-centre tracked text */
  text-transform: uppercase;
  text-shadow:
    0 0 0.45em var(--color-accent-glow),
    0 0.06em 0.35em rgba(0, 0, 0, 0.65);
}

.hero__tagline {
  font-size: clamp(0.72rem, 1.9vw, 1.05rem);
  font-weight: 500;
  letter-spacing: 0.38em;
  text-indent: 0.38em;
  text-transform: uppercase;
  color: var(--color-text-soft);
  text-shadow: 0 1px 12px rgba(0, 0, 0, 0.6);
}

/* ---------- Download block ---------------------------------------------- */
.download {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: clamp(0.85rem, 2.4vh, 1.4rem);
  width: 100%; /* keep the button row wrapping inside the viewport */
  margin-top: clamp(1.75rem, 6vh, 3.5rem);
}

.download__title {
  display: flex;
  align-items: center;
  gap: clamp(0.7rem, 2vw, 1.15rem);
  font-size: clamp(0.7rem, 1.5vw, 0.85rem);
  font-weight: 500;
  letter-spacing: 0.45em;
  text-indent: 0.45em;
  text-transform: uppercase;
  color: var(--color-text-soft);
}

.download__title::before,
.download__title::after {
  content: "";
  width: clamp(1.5rem, 5vw, 3.25rem);
  height: 1px;
  background: linear-gradient(90deg, rgba(255, 255, 255, 0), var(--color-line));
}

.download__title::after {
  background: linear-gradient(90deg, var(--color-line), rgba(255, 255, 255, 0));
}

.download__list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  width: 100%;
  gap: clamp(0.5rem, 1.3vw, 0.9rem);
}

/* ---------- Download buttons -------------------------------------------- */
/* Text-only: no background, no border, no glass panel. Icon + label sit
   directly on the artwork and glow brand blue on hover or keyboard focus. */
.btn-line {
  display: inline-flex;
  align-items: center;
  gap: clamp(0.6rem, 1.4vw, 0.9rem);
  padding: clamp(0.75rem, 1.8vw, 1.05rem) clamp(0.95rem, 2.4vw, 1.55rem);
  border: 0;
  border-radius: 0;
  background-color: transparent;
  color: var(--color-text);
  font-family: inherit;
  font-size: clamp(0.85rem, 1.9vw, 1.15rem);
  font-weight: 500;
  letter-spacing: 0.16em;
  text-decoration: none;
  white-space: nowrap;
  text-shadow: 0 1px 12px rgba(0, 0, 0, 0.7);
  transition:
    color var(--duration) var(--ease),
    text-shadow var(--duration) var(--ease),
    transform var(--duration) var(--ease);
}

.btn-line__icon {
  display: block;
  width: clamp(1.35rem, 2.6vw, 1.75rem);
  height: clamp(1.35rem, 2.6vw, 1.75rem);
  object-fit: contain;
  filter: drop-shadow(0 1px 6px rgba(0, 0, 0, 0.65));
}

.btn-line__label {
  display: block;
}

.btn-line:hover,
.btn-line:focus-visible {
  color: var(--color-text);
  text-shadow:
    0 0 0.6em var(--color-accent-glow),
    0 0 0.22em var(--color-accent),
    0 1px 12px rgba(0, 0, 0, 0.7);
  transform: translateY(-1px);
}

.btn-line:hover .btn-line__icon,
.btn-line:focus-visible .btn-line__icon {
  filter: drop-shadow(0 0 8px var(--color-accent-glow));
}

.btn-line:focus-visible {
  outline: 2px solid var(--color-text);
  outline-offset: 3px;
}

.btn-line:active {
  transform: translateY(0) scale(0.985);
}

/* ---------- Footer ------------------------------------------------------- */
.site-footer {
  display: flex;
  justify-content: center;
  align-items: center;
  padding-top: clamp(0.5rem, 1.6vh, 1.15rem);
}

.site-footer__line {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: clamp(0.68rem, 1.15vw, 0.8rem);
  letter-spacing: 0.12em;
  color: var(--color-text-muted);
}

.site-footer__sep {
  color: rgba(255, 255, 255, 0.32);
}

.site-footer__link {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition:
    color var(--duration) var(--ease),
    border-color var(--duration) var(--ease);
}

.site-footer__link:hover {
  color: var(--color-text);
  border-bottom-color: rgba(255, 255, 255, 0.7);
}

.site-footer__link:focus-visible {
  outline: 2px solid var(--color-text);
  outline-offset: 3px;
}

/* ---------- Responsive tweaks ------------------------------------------- */
@media (max-width: 480px) {
  .site-header__nav {
    --nav-gap: 0.75rem;
  }

  .nav-link {
    letter-spacing: 0.1em;
  }

  .btn-line {
    letter-spacing: 0.12em;
  }
}

@media (max-height: 620px) and (orientation: landscape) {
  .hero {
    padding-block: 1.5rem;
  }

  .download {
    margin-top: 1rem;
  }

  .hero__title {
    font-size: clamp(1.8rem, 7.2vw, 3.6rem);
  }
}

/* ---------- Motion preferences ------------------------------------------ */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }

  .btn-line:hover,
  .btn-line:focus-visible,
  .btn-line:active {
    transform: none;
  }
}