/* ============================================================
   base.css — GSV Sales Marketing Site
   Covers: variables, reset, layout, nav, buttons, animations
   ============================================================ */

/* ── CSS Variables ─────────────────────────────────────────── */
:root {
  --black:        #0d0d0d;
  --black-2:      #111111;
  --black-3:      #181818;
  --white:        #ffffff;
  --off-white:    #f7f7f7;
  --orange:       #f05a22;
  --orange-dark:  #d44e1a;
  --gray-1:       #888888;
  --gray-2:       #555555;
  --gray-3:       #333333;
  --gray-light:   #e4e4e4;

  --font:         'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --nav-h:        72px;
  --section-pad:  96px;
  --container:    1300px;
  --radius:       4px;
  --transition:   0.3s ease;
}

/* ── Reset ─────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html  { scroll-behavior: smooth; font-size: 16px; }
body  {
  font-family: var(--font);
  background:  var(--white);
  color:       var(--black);
  line-height: 1.6;
  overflow-x:  hidden;
  -webkit-font-smoothing: antialiased;
}
img   { max-width: 100%; display: block; }
a     { text-decoration: none; color: inherit; }
button{ cursor: pointer; border: none; background: none; font-family: var(--font); }
ul    { list-style: none; }

/* ── Layout ────────────────────────────────────────────────── */
.container {
  max-width: var(--container);
  margin:    0 auto;
  padding:   0 24px;
}

/* When container width fills viewport, ensure minimum side padding */
@media (max-width: 1348px) {
  .container {
    padding: 0 max(24px, 3vw);
  }
}

/* Section theme helpers */
.section-dark  { background: var(--black-2); padding: var(--section-pad) 0; }
.section-light { background: var(--white);   padding: var(--section-pad) 0; }
.section-accent{ background: var(--black);   padding: var(--section-pad) 0; position: relative; overflow: hidden; }

/* Shared section labels */
.section-label {
  display:       inline-flex;
  align-items:   center;
  gap:           8px;
  font-size:     11px;
  font-weight:   700;
  letter-spacing:0.14em;
  text-transform:uppercase;
  color:         var(--orange);
  margin-bottom: 14px;
}
.section-label--light { color: rgba(255,255,255,0.55); }

.section-headline {
  font-size:     clamp(28px, 4vw, 46px);
  font-weight:   800;
  line-height:   1.1;
  letter-spacing:-0.02em;
  color:         var(--white);
  margin-bottom: 18px;
}
.section-headline--dark { color: var(--black); }

.section-sub {
  font-size:     17px;
  color:         rgba(255,255,255,0.55);
  max-width:     540px;
  margin-bottom: 56px;
  line-height:   1.75;
}
.section-sub--dark { color: var(--gray-1); }

/* ── Buttons ───────────────────────────────────────────────── */
.btn {
  display:        inline-flex;
  align-items:    center;
  justify-content:center;
  gap:            6px;
  padding:        10px 20px;
  font-size:      14px;
  font-weight:    600;
  letter-spacing: 0.02em;
  border-radius:  var(--radius);
  transition:     color 0.35s ease, border-color 0.35s ease;
  white-space:    nowrap;
  position:       relative;
  overflow:       hidden;
  z-index:        1;
}

/* Swipe-up background effect */
.btn::before {
  content:    '';
  position:   absolute;
  bottom:     0;
  left:       0;
  right:      0;
  height:     0%;
  z-index:    -1;
  transition: height 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.btn:hover::before {
  height:     100%;
}
.btn--large { padding: 14px 28px; font-size: 15px; }

/* Variants */
.btn--primary {
  background:    var(--black);
  color:         var(--white);
  letter-spacing:0.06em;
  font-size:     12px;
}
.btn--primary::before { background: var(--gray-light); }
.btn--primary:hover { color: var(--black); }

.btn--dark { background: var(--black); color: var(--white); }
.btn--dark::before { background: var(--gray-light); }
.btn--dark:hover { color: var(--black); }

.btn--accent { background: var(--orange); color: var(--white); }
.btn--accent::before { background: var(--white); }
.btn--accent:hover { color: var(--black); }

.btn--white { background: var(--white); color: var(--black); }
.btn--white::before { background: var(--black); }
.btn--white:hover { color: var(--white); }

.btn--ghost-dark {
  border: 1.5px solid var(--gray-light);
  color:  var(--gray-2);
  background: transparent;
}
.btn--ghost-dark::before { background: var(--black); }
.btn--ghost-dark:hover { border-color: var(--black); color: var(--white); }

.btn--outline-dark {
  border: 1.5px solid var(--black);
  color:  var(--black);
  background: transparent;
}
.btn--outline-dark::before { background: var(--black); }
.btn--outline-dark:hover { color: var(--white); }

.btn--ghost-light {
  border: 1.5px solid rgba(255,255,255,0.2);
  color:  rgba(255,255,255,0.65);
  background: transparent;
}
.btn--ghost-light::before { background: var(--white); }
.btn--ghost-light:hover { border-color: var(--white); color: var(--black); }

/* ── Navigation ─────────────────────────────────────────────── */
.nav {
  position:      fixed;
  top:           0; left: 0; right: 0;
  z-index:       100;
  background:    var(--white);
  border-bottom: 1px solid var(--gray-light);
  /* Fade + slide for scroll-hide behavior */
  transition:    transform 0.38s ease, opacity 0.38s ease, box-shadow var(--transition);
}
.nav.scrolled   { box-shadow: 0 2px 24px rgba(0,0,0,0.07); }
/* Applied by JS when user scrolls down */
.nav--hidden    { transform: translateY(-100%); opacity: 0; pointer-events: none; }

.nav__inner {
  display:     flex;
  align-items: center;
  height:      var(--nav-h);
  gap:         32px;
}

.nav__logo {
  display:        flex;
  align-items:    center;
  gap:            10px;
  font-size:      18px;
  font-weight:    800;
  color:          var(--black);
  flex-shrink:    0;
  letter-spacing: -0.02em;
}

/* GET STARTED sits on the right edge */
.nav__actions {
  display:     flex;
  align-items: center;
  gap:         10px;
  margin-left: auto;
}

/* ── Footer ─────────────────────────────────────────────────── */
.footer {
  background: var(--black);
  border-top: 1px solid rgba(255,255,255,0.06);
  padding: 36px 0;
}

.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}

.footer__logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 15px;
  font-weight: 700;
  color: rgba(255,255,255,0.5);
}

.footer__links {
  display: flex;
  align-items: center;
  gap: 22px;
  flex-wrap: wrap;
}

.footer__links a {
  font-size: 13px;
  color: rgba(255,255,255,0.32);
  transition: color var(--transition);
}

.footer__links a:hover {
  color: rgba(255,255,255,0.65);
}

.footer__copy {
  font-size: 12px;
  color: rgba(255,255,255,0.22);
}

/* ── Scroll Animations ──────────────────────────────────────── */
.fade-in {
  opacity:   0;
  transform: translateY(22px);
  transition:opacity 0.75s ease, transform 0.75s ease;
}
.fade-in.visible { opacity: 1; transform: none; }

.reveal {
  opacity:   0;
  transform: translateY(28px);
  transition:opacity 0.65s ease, transform 0.65s ease;
}
.reveal.visible { opacity: 1; transform: none; }

/* Stagger siblings */
.reveal:nth-child(2) { transition-delay: 0.10s; }
.reveal:nth-child(3) { transition-delay: 0.20s; }
.reveal:nth-child(4) { transition-delay: 0.30s; }
.reveal:nth-child(5) { transition-delay: 0.15s; }
.reveal:nth-child(6) { transition-delay: 0.25s; }

/* ── Responsive ─────────────────────────────────────────────── */
@media (max-width: 1024px) {
  :root { --section-pad: 76px; }
  .container { padding: 0 32px; }
}

@media (max-width: 768px) {
  :root { --section-pad: 60px; }
  .container { padding: 0 24px; }
  .footer__inner { flex-direction: column; text-align: center; }
}