/* ============================================================
   THIS FRAGILE SKY — landing page
   Concept: an NCDL field manual, printed on sun-bleached paper,
   about a beautiful world. NASA-technical bones, Nausicaa daylight —
   with an optional nightfall (dark) theme. Shared tokens drive both.
   ============================================================ */

:root{
  /* type roles */
  --wordmark: 'Poppins', system-ui, sans-serif;   /* stand-in for the book's Century-Gothic-style face */
  --head: 'Overpass', system-ui, sans-serif;       /* 60s NASA field-manual grotesque */
  --mono: 'Overpass Mono', ui-monospace, monospace;/* technical data + labels */
  --body: 'Montserrat', system-ui, sans-serif;

  /* palette — sun-bleached paper, clear sky blue, sun-faded strawberry */
  --paper:   #f4efe4;
  --paper-2: #ece4d4;
  --paper-3: #e3dac6;
  --ink:     #34404a;   /* soft slate, never pure black */
  --ink-soft:#6d7783;
  --steel:   #4f7d9e;   /* the book's title blue */
  --steel-deep:#3d6a8a;
  --sky:     #a9cbe0;
  --sky-pale:#cfe1ea;
  --berry:   #db5c6d;   /* sun-faded strawberry red */
  --berry-deep:#c2465a;
  --sage:    #90a074;
  --rule:    rgba(52,64,74,.16);
  --rule-soft:rgba(52,64,74,.09);

  /* hero sky */
  --sky-top:     #b6d4e4;
  --sky-mid:     #d2e2e8;
  --sky-horizon: #f2ead9;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:var(--body);
  font-size:17px;
  line-height:1.72;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
a{color:inherit;text-decoration:none}
img{max-width:100%}
.wrap{width:min(1180px,90vw);margin-inline:auto}
.visually-hidden{
  position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;
  clip:rect(0 0 0 0);white-space:nowrap;border:0;
}

/* ---------- shared type helpers ---------- */
.mono{font-family:var(--mono);font-weight:400}
.tag{
  font-family:var(--mono);text-transform:uppercase;letter-spacing:.22em;
  font-size:.68rem;color:var(--steel);font-weight:600;
}
.tag--berry{color:var(--berry)}
.h-face{
  font-family:var(--head);font-weight:700;text-transform:uppercase;
  letter-spacing:.005em;line-height:1;text-wrap:balance;color:var(--ink);
}

/* ---------- manual header bar ---------- */
.topstrip{
  position:fixed;top:0;left:0;right:0;z-index:50;
  background:color-mix(in srgb, var(--paper) 88%, transparent);
  border-bottom:1px solid var(--rule);
  backdrop-filter:blur(8px);
}
.topstrip .wrap{
  display:flex;align-items:center;justify-content:space-between;
  height:60px;
}
.brand{
  font-family:var(--wordmark);text-transform:uppercase;letter-spacing:.14em;
  font-size:.9rem;color:var(--steel);display:flex;align-items:center;gap:.05em;
}
.brand b{font-weight:600}
.brand i{font-weight:300;font-style:normal}
.nav{display:flex;align-items:center;gap:2rem}
.nav a{
  font-family:var(--head);text-transform:uppercase;letter-spacing:.14em;
  font-size:.74rem;font-weight:600;color:var(--ink-soft);
  padding:4px 0;border-bottom:2px solid transparent;transition:color .18s,border-color .18s;
}
.nav a:hover,.nav a:focus-visible{color:var(--ink);border-color:var(--berry)}
.nav a.active{color:var(--ink);border-color:var(--steel)}

/* ---------- hero / cover ---------- */
.hero{
  position:relative;min-height:100svh;display:flex;flex-direction:column;
  justify-content:center;align-items:center;text-align:center;overflow:hidden;
  padding:120px 0 80px;
  background:linear-gradient(180deg,var(--sky-top) 0%,var(--sky-mid) 46%,var(--sky-horizon) 100%);
}
#wind{position:absolute;inset:0;width:100%;height:100%;display:block;z-index:1}
/* warm sun glow, upper area */
.hero::before{
  content:"";position:absolute;top:-14%;right:-6%;width:60vw;height:60vw;z-index:0;
  background:radial-gradient(circle, rgba(247,231,196,.85) 0%, rgba(247,231,196,0) 60%);
  pointer-events:none;
}
.hero-inner{position:relative;z-index:3;width:min(1080px,92vw)}

.hero-meta{
  display:flex;justify-content:center;gap:1.6rem;flex-wrap:wrap;
  margin-bottom:2.4rem;color:var(--steel-deep);
}
.hero-meta span{font-family:var(--mono);font-size:.66rem;letter-spacing:.2em;text-transform:uppercase}
.hero-meta span b{color:var(--berry);font-weight:600}

.hero-cta{display:flex;flex-wrap:wrap;gap:14px;justify-content:center;margin-top:2.4rem}

.btn{
  font-family:var(--head);text-transform:uppercase;letter-spacing:.1em;
  font-size:.78rem;font-weight:700;padding:15px 30px;border-radius:2px;cursor:pointer;
  display:inline-flex;align-items:center;gap:.7ch;border:2px solid transparent;
  transition:transform .15s ease,background .2s,color .2s,border-color .2s;
}
.btn:hover{transform:translateY(-2px)}
.btn-primary{background:var(--berry);color:#fbf3ea}
.btn-primary:hover{background:var(--berry-deep)}
.btn-ghost{border-color:var(--steel);color:var(--steel-deep)}
.btn-ghost:hover{background:var(--steel);color:#f4efe4;border-color:var(--steel)}

/* theme toggle button (used in the top bar on every page) */
.theme-btn{
  display:inline-grid;place-items:center;width:34px;height:34px;flex:none;
  border:1px solid var(--rule);border-radius:50%;background:transparent;
  color:var(--ink-soft);cursor:pointer;transition:color .18s,border-color .18s;
}
.theme-btn:hover,.theme-btn:focus-visible{color:var(--ink);border-color:var(--steel)}
.theme-btn svg{width:16px;height:16px}

.scrollcue{
  position:absolute;left:50%;bottom:20px;transform:translateX(-50%);z-index:4;
  font-family:var(--mono);text-transform:uppercase;letter-spacing:.24em;
  font-size:.58rem;color:var(--steel-deep);display:flex;flex-direction:column;
  align-items:center;gap:8px;opacity:.8;
}
.scrollcue .bar{width:1px;height:30px;background:var(--steel-deep);opacity:.6;
  animation:cue 2.4s ease-in-out infinite;transform-origin:top}
@keyframes cue{0%,100%{transform:scaleY(.35)}50%{transform:scaleY(1)}}

/* ---------- section frame (manual sections) ---------- */
.band{padding:clamp(78px,11vh,140px) 0;position:relative}
.sec-head{
  display:grid;grid-template-columns:auto 1fr;gap:1.4rem;align-items:start;
  padding-bottom:1.6rem;margin-bottom:3rem;border-bottom:1px solid var(--rule);
}
.sec-no{
  font-family:var(--mono);font-size:.72rem;letter-spacing:.16em;color:var(--berry);
  text-transform:uppercase;font-weight:600;white-space:nowrap;padding-top:.55rem;
}
.sec-head h2{
  font-family:var(--head);font-weight:700;text-transform:uppercase;letter-spacing:.01em;
  font-size:clamp(1.8rem,4.6vw,3.3rem);line-height:1;margin:0;color:var(--ink);text-wrap:balance;
}
.sec-head .sub{
  grid-column:2;font-family:var(--mono);font-size:.72rem;color:var(--ink-soft);
  letter-spacing:.1em;margin-top:.7rem;text-transform:uppercase;
}

/* ---------- creed / opening line ---------- */
.creed{background:var(--paper-2);border-top:1px solid var(--rule);border-bottom:1px solid var(--rule)}
.creed .wrap{display:grid;grid-template-columns:1fr 1fr;gap:clamp(2rem,6vw,5rem);align-items:center}
.creed blockquote{
  margin:0;font-family:var(--head);font-weight:300;
  font-size:clamp(2rem,5.6vw,4.4rem);line-height:1.02;color:var(--steel);
  text-wrap:balance;letter-spacing:.005em;
}
.creed blockquote b{font-weight:600;color:var(--berry)}
.creed p{margin:0;color:var(--ink);max-width:52ch}
.creed p + p{margin-top:1.1rem}
.creed em{font-style:italic;color:var(--berry-deep);font-weight:500}

/* ---------- doctrine / tenets ---------- */
.tenet-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:0;border:1px solid var(--rule)}
.tenet{
  padding:2.4rem 2rem 2.8rem;display:flex;flex-direction:column;gap:.9rem;
  border-right:1px solid var(--rule);transition:background .25s;
}
.tenet:last-child{border-right:none}
.tenet:hover{background:var(--paper-2)}
.tenet .tcode{font-family:var(--mono);font-size:.7rem;letter-spacing:.14em;color:var(--sage);text-transform:uppercase;font-weight:600}
.tenet h3{
  font-family:var(--head);font-weight:700;text-transform:uppercase;letter-spacing:.01em;
  font-size:1.35rem;line-height:1.04;margin:.1rem 0 0;color:var(--ink);text-wrap:balance;
}
.tenet .rule{width:30px;height:3px;background:var(--berry);margin:.15rem 0 .35rem}
.tenet p{margin:0;color:var(--ink-soft);font-size:.96rem;line-height:1.62}

/* ---------- theater / setting ---------- */
.setting{background:var(--paper)}
.setting .wrap{max-width:64ch}
.setting .lede{
  font-family:var(--wordmark);font-weight:300;font-size:clamp(1.3rem,2.6vw,1.95rem);
  line-height:1.26;color:var(--steel-deep);margin:0 0 1.5rem;text-wrap:balance;
}
.setting p{color:var(--ink);margin:0 0 1.1rem;max-width:54ch}
.setting p strong{color:var(--berry-deep);font-weight:600}

/* ---------- field kit strip ---------- */
.kit{background:var(--paper-3);border-top:1px solid var(--rule);border-bottom:1px solid var(--rule)}
.kit .wrap{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:2.5rem}
.kit .khead{max-width:22ch}
.kit .khead .tag{margin-bottom:.7rem;display:block}
.kit .khead p{
  margin:0;font-family:var(--head);font-weight:700;text-transform:uppercase;
  font-size:clamp(1.3rem,3vw,2rem);line-height:1.02;color:var(--ink);text-wrap:balance;letter-spacing:.01em;
}
.kit ul{display:flex;flex-wrap:wrap;gap:.6rem;max-width:36ch;margin:0;padding:0}
.kit li{
  list-style:none;font-family:var(--mono);text-transform:uppercase;letter-spacing:.08em;
  font-size:.66rem;font-weight:400;color:var(--ink);
  border:1px solid var(--steel);border-radius:2px;padding:.5rem .8rem;background:transparent;
}

/* ---------- closer ---------- */
.closer{
  position:relative;text-align:center;overflow:hidden;
  background:linear-gradient(180deg,var(--sky-pale) 0%,var(--paper) 100%);
  border-top:1px solid var(--rule);
}
.closer .wrap{padding:clamp(90px,13vh,160px) 0}
.closer .tag{display:block;margin-bottom:1.2rem}
.closer h2{
  font-family:var(--head);font-weight:700;text-transform:uppercase;
  font-size:clamp(1.9rem,5.4vw,4rem);line-height:1.02;margin:0 auto;color:var(--ink);
  max-width:16ch;text-wrap:balance;letter-spacing:.01em;
}
.closer .hero-cta{margin-top:2.4rem}

/* ---------- footer / manual colophon ---------- */
footer{background:var(--ink);color:var(--paper)}
footer .wrap{padding:56px 0 40px;display:flex;flex-wrap:wrap;justify-content:space-between;gap:2rem;align-items:flex-start}
footer .fbrand{font-family:var(--wordmark);text-transform:uppercase;letter-spacing:.12em;font-size:1rem;color:var(--sky)}
footer .fbrand b{font-weight:600}
footer .fbrand i{font-weight:300;font-style:normal}
footer .fnote{color:rgba(244,239,228,.62);font-size:.82rem;max-width:40ch;margin:.7rem 0 0;line-height:1.6}
footer nav{display:flex;flex-direction:column;gap:.7rem}
footer nav a{font-family:var(--head);text-transform:uppercase;letter-spacing:.14em;font-size:.72rem;color:rgba(244,239,228,.66);font-weight:600}
footer nav a:hover{color:var(--paper)}
.colophon{
  width:100%;border-top:1px solid rgba(244,239,228,.14);margin-top:1rem;padding-top:1.4rem;
  font-family:var(--mono);color:rgba(244,239,228,.5);font-size:.68rem;letter-spacing:.08em;text-transform:uppercase;
}

/* ---------- scroll reveal ---------- */
.reveal{opacity:0;transform:translateY(20px);transition:opacity .7s ease,transform .7s ease}
.reveal.in{opacity:1;transform:none}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal{opacity:1;transform:none;transition:none}
  .scrollcue .bar{animation:none}
}

/* ---------- responsive ---------- */
@media (max-width:860px){
  .nav{gap:1.1rem}
  .nav a.hideable{display:none}
  .creed .wrap{grid-template-columns:1fr;gap:2rem}
  .tenet-grid{grid-template-columns:1fr}
  .tenet{border-right:none;border-bottom:1px solid var(--rule)}
  .tenet:last-child{border-bottom:none}
}
@media (max-width:560px){
  body{font-size:16px}
  .kit .wrap{gap:1.6rem}
}

/* ============================================================
   NIGHTFALL — the shared dark theme (drives every page).
   Applied when the OS prefers dark (and the viewer hasn't forced
   light), or when the toggle stamps data-theme="dark".
   ============================================================ */
:root[data-theme="dark"]{
  color-scheme:dark;
  --paper:#14191f; --paper-2:#1b222a; --paper-3:#222b34;
  --ink:#e7e3d9; --ink-soft:#9aa3ad;
  --steel:#7fb2d2; --steel-deep:#a6cee6;
  --sky:#8fb9d6; --sky-pale:#223140;
  --berry:#e87f8e; --berry-deep:#f0a0ab; --sage:#abbd91;
  --rule:rgba(231,228,219,.14); --rule-soft:rgba(231,228,219,.07);
  --sky-top:#0f1a24; --sky-mid:#17242f; --sky-horizon:#25333f;
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    color-scheme:dark;
    --paper:#14191f; --paper-2:#1b222a; --paper-3:#222b34;
    --ink:#e7e3d9; --ink-soft:#9aa3ad;
    --steel:#7fb2d2; --steel-deep:#a6cee6;
    --sky:#8fb9d6; --sky-pale:#223140;
    --berry:#e87f8e; --berry-deep:#f0a0ab; --sage:#abbd91;
    --rule:rgba(231,228,219,.14); --rule-soft:rgba(231,228,219,.07);
    --sky-top:#0f1a24; --sky-mid:#17242f; --sky-horizon:#25333f;
  }
}

/* landing-specific components with hardcoded colors need a night variant:
   the warm sun becomes a faint moon glow, and the footer stays a dark plate. */
:root[data-theme="dark"] .hero::before{
  background:radial-gradient(circle, rgba(190,210,230,.14) 0%, rgba(190,210,230,0) 60%);
}
:root[data-theme="dark"] footer{background:#0e1319;color:var(--ink)}
:root[data-theme="dark"] footer nav a:hover{color:var(--ink)}
:root[data-theme="dark"] .btn-ghost:hover{color:var(--paper)}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]) .hero::before{
    background:radial-gradient(circle, rgba(190,210,230,.14) 0%, rgba(190,210,230,0) 60%);
  }
  :root:not([data-theme="light"]) footer{background:#0e1319;color:var(--ink)}
  :root:not([data-theme="light"]) footer nav a:hover{color:var(--ink)}
  :root:not([data-theme="light"]) .btn-ghost:hover{color:var(--paper)}
}