/* ==========================================================================
   FUTUREE STUDY DESIGN SYSTEM — "Monochrome"
   Future of Online Learning — shared foundation
   Deep black/grey architecture + glass panels + white/grey accents
   ========================================================================== */

/* ---------- Tokens ---------- */
:root{
  /* Atmosphere */
  --void:        #060606;
  --bg-deep:     #0a0a0b;
  --bg-elevated: #0e0e10;
  --bg-card:     #131315;
  --line:        rgba(255,255,255,.10);
  --line-soft:   rgba(255,255,255,.05);
  --ink:         #f5f5f5;
  --ink-dim:     #a8a8ac;
  --ink-faint:   #6e6e73;

  /* Glass */
  --glass-bg:     rgba(255,255,255,.04);
  --glass-bg-hi:  rgba(255,255,255,.075);
  --glass-border: rgba(255,255,255,.13);

  /* Accent spectrum — black / white / grey family */
  --indigo:  #27272a;
  --violet:  #52525b;
  --magenta: #a1a1aa;
  --cyan:    #f4f4f5;
  --yellow:  #d4d4d8;
  --orange:  #71717a;

  /* Gradients */
  --g-primary: linear-gradient(135deg, var(--indigo) 0%, var(--violet) 52%, var(--cyan) 100%);
  --g-cool:    linear-gradient(135deg, var(--cyan) 0%, var(--violet) 100%);
  --g-warm:    linear-gradient(135deg, var(--orange) 0%, var(--yellow) 100%);
  --g-flux:    linear-gradient(120deg, var(--cyan) 0%, var(--violet) 45%, var(--magenta) 75%, var(--orange) 100%);
  --g-text:    linear-gradient(100deg, #f5f5f5 0%, #d4d4d8 30%, var(--violet) 55%, var(--cyan) 85%);

  /* Type */
  --f-display: "Outfit", "Geist", "Inter", sans-serif;
  --f-body: "Inter", "Geist", sans-serif;
  --f-mono: "JetBrains Mono", ui-monospace, Menlo, monospace;

  /* Shape / rhythm */
  --radius-sm: 10px;
  --radius-md: 18px;
  --radius-lg: 28px;
  --radius-xl: 40px;
  --container: 1280px;
  --gutter: clamp(1.25rem, 4vw, 3rem);

  /* Motion */
  --ease-out: cubic-bezier(.16,1,.3,1);
  --ease-spring: cubic-bezier(.34,1.56,.64,1);
  --dur-fast: .18s;
  --dur-med: .45s;
  --dur-slow: .9s;
}

/* ---------- Reset ---------- */
*, *::before, *::after{ box-sizing: border-box; margin:0; padding:0; }
html{ scroll-behavior:smooth; color-scheme: dark; }
@media (prefers-reduced-motion: reduce){
  html{ scroll-behavior:auto; }
  *, *::before, *::after{ animation-duration:.001ms !important; animation-iteration-count:1 !important; transition-duration:.001ms !important; scroll-behavior:auto !important; }
}
body{
  background: var(--void);
  color: var(--ink);
  font-family: var(--f-body);
  font-weight: 400;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  position: relative;
}
img, svg{ display:block; max-width:100%; }
a{ color:inherit; text-decoration:none; }
ul, ol{ list-style:none; }
button, input, textarea, select{ font: inherit; color: inherit; }
button{ cursor:pointer; background:none; border:none; }
h1,h2,h3,h4{ font-family: var(--f-display); line-height:1.08; letter-spacing:-.02em; font-weight:700; }
:focus-visible{ outline: 2px solid var(--cyan); outline-offset: 3px; border-radius: 4px; }

/* ---------- Atmosphere layers (grain + grid + blobs + spotlight) ---------- */
.bg-atmosphere{ position: fixed; inset:0; z-index:-3; overflow:hidden; background:
    radial-gradient(ellipse 90% 60% at 50% -10%, rgba(39,39,42,.16), transparent 60%),
    radial-gradient(ellipse 70% 50% at 100% 10%, rgba(161,161,170,.10), transparent 60%),
    var(--void);
}
.bg-grid{ position:fixed; inset:0; z-index:-2; pointer-events:none;
  background-image:
    linear-gradient(rgba(148,180,255,.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(148,180,255,.05) 1px, transparent 1px),
    linear-gradient(rgba(148,180,255,.09) 1px, transparent 1px),
    linear-gradient(90deg, rgba(148,180,255,.09) 1px, transparent 1px);
  background-size: 64px 64px, 64px 64px, 320px 320px, 320px 320px;
  mask-image: radial-gradient(ellipse 80% 65% at 50% 20%, black 0%, transparent 75%);
}
.bg-grain{ position:fixed; inset:0; z-index:-1; pointer-events:none; opacity:.05; mix-blend-mode:overlay;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}
.spotlight{ position:fixed; inset:0; z-index:-1; pointer-events:none; opacity:0; transition:opacity .6s var(--ease-out);
  background: radial-gradient(560px circle at var(--mx,50%) var(--my,30%), rgba(82,82,91,.14), transparent 70%);
}
.spotlight.is-active{ opacity:1; }

.blob-field{ position:absolute; inset:0; overflow:hidden; z-index:-1; pointer-events:none; }
.blob{ position:absolute; border-radius:50%; filter: blur(70px); opacity:.55; will-change: transform; }
.blob-1{ width:520px; height:520px; background:var(--indigo); top:-180px; left:-140px; animation: drift1 22s ease-in-out infinite; }
.blob-2{ width:420px; height:420px; background:var(--magenta); top:10%; right:-160px; animation: drift2 26s ease-in-out infinite; }
.blob-3{ width:380px; height:380px; background:var(--cyan); bottom:-160px; left:20%; animation: drift3 30s ease-in-out infinite; opacity:.35; }
.blob-4{ width:300px; height:300px; background:var(--orange); bottom:5%; right:10%; animation: drift1 18s ease-in-out infinite reverse; opacity:.3; }
@keyframes drift1{ 0%,100%{ transform: translate(0,0) scale(1); } 50%{ transform: translate(60px,40px) scale(1.12); } }
@keyframes drift2{ 0%,100%{ transform: translate(0,0) scale(1); } 50%{ transform: translate(-50px,60px) scale(.9); } }
@keyframes drift3{ 0%,100%{ transform: translate(0,0) scale(1); } 50%{ transform: translate(40px,-50px) scale(1.08); } }

.floaters{ position:absolute; inset:0; pointer-events:none; z-index:0; }
.floater{ position:absolute; opacity:.5; animation: float-y 7s ease-in-out infinite; }
@keyframes float-y{ 0%,100%{ transform: translateY(0) rotate(0deg); } 50%{ transform: translateY(-22px) rotate(8deg); } }

/* ---------- Container / layout helpers ---------- */
.container{ width:100%; max-width: var(--container); margin-inline:auto; padding-inline: var(--gutter); position:relative; }
.container-wide{ width:100%; max-width: 1440px; margin-inline:auto; padding-inline: var(--gutter); position:relative; }
section{ position:relative; }

/* ---------- Eyebrow / tags ---------- */
.eyebrow{ display:inline-flex; align-items:center; gap:.5em; font-family: var(--f-mono); font-size:.72rem; letter-spacing:.16em; text-transform:uppercase; color: var(--ink-dim);
  padding:.45em 1em; border:1px solid var(--glass-border); border-radius: 999px; background: var(--glass-bg); backdrop-filter: blur(12px); }
.eyebrow::before{ content:""; width:6px; height:6px; border-radius:50%; background: var(--g-primary); box-shadow: 0 0 12px var(--violet); }

/* ---------- Display headline / gradient text ---------- */
.grad-text{ background: var(--g-text); -webkit-background-clip:text; background-clip:text; color:transparent; }
.grad-text-warm{ background: var(--g-warm); -webkit-background-clip:text; background-clip:text; color:transparent; }
.grad-text-cool{ background: var(--g-cool); -webkit-background-clip:text; background-clip:text; color:transparent; }
.chroma{ text-shadow: 0 0 30px rgba(82,82,91,.35), 0 0 70px rgba(161,161,170,.18); }

/* ---------- Buttons ---------- */
.btn-gradient, .btn-outline, .btn-ghost{
  display:inline-flex; align-items:center; justify-content:center; gap:.6em;
  font-family: var(--f-display); font-weight:600; font-size:.95rem; letter-spacing:-.01em;
  padding:.95em 1.8em; border-radius:999px; white-space:nowrap;
  transition: transform var(--dur-fast) var(--ease-spring), box-shadow var(--dur-med) var(--ease-out), background var(--dur-med), border-color var(--dur-med);
}
.btn-gradient{ background: var(--g-primary); color:#fff; box-shadow: 0 1px 0 rgba(255,255,255,.25) inset, 0 12px 30px -8px rgba(82,82,91,.55); }
.btn-gradient:hover{ transform: translateY(-2px) scale(1.02); box-shadow: 0 1px 0 rgba(255,255,255,.3) inset, 0 18px 40px -8px rgba(161,161,170,.6); }
.btn-outline{ border:1px solid var(--glass-border); color: var(--ink); background: var(--glass-bg); backdrop-filter: blur(10px); }
.btn-outline:hover{ border-color: rgba(82,82,91,.5); background: rgba(82,82,91,.08); transform: translateY(-2px); }
.btn-ghost{ color: var(--ink-dim); padding:.6em .3em; }
.btn-ghost:hover{ color: var(--ink); }
.btn-sm{ padding:.6em 1.3em; font-size:.82rem; }

/* ---------- Glass panels & cards ---------- */
.glass{ background: var(--glass-bg); border:1px solid var(--glass-border); backdrop-filter: blur(18px) saturate(140%); -webkit-backdrop-filter: blur(18px) saturate(140%); border-radius: var(--radius-lg); }
.glass-hi{ background: var(--glass-bg-hi); }
.card{
  position:relative; background: linear-gradient(180deg, rgba(255,255,255,.05), rgba(255,255,255,.015));
  border:1px solid var(--glass-border); border-radius: var(--radius-md); padding: 1.9rem;
  box-shadow: 0 1px 0 rgba(255,255,255,.06) inset, 0 20px 50px -24px rgba(0,0,0,.7);
  transition: transform var(--dur-med) var(--ease-out), border-color var(--dur-med), box-shadow var(--dur-med);
}
.card::before{ content:""; position:absolute; inset:0; border-radius:inherit; padding:1px;
  background: linear-gradient(140deg, rgba(255,255,255,.16), transparent 30%, transparent 70%, rgba(255,255,255,.08));
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor; mask-composite: exclude; pointer-events:none;
}
.card:hover{ transform: translateY(-6px); border-color: rgba(82,82,91,.4); box-shadow: 0 1px 0 rgba(255,255,255,.08) inset, 0 30px 60px -20px rgba(39,39,42,.35); }
.card-accent-top{ position:absolute; top:0; left:1.4rem; right:1.4rem; height:2px; border-radius:2px; background: var(--g-primary); }

/* ---------- Chips / pills ---------- */
.chip{ display:inline-flex; align-items:center; gap:.4em; font-size:.76rem; font-weight:600; padding:.4em .9em; border-radius:999px; border:1px solid var(--glass-border); color: var(--ink-dim); background: var(--glass-bg); }
.chip.is-active{ color:#fff; border-color:transparent; background: var(--g-primary); }

/* ---------- Header ---------- */
.site-header{ position: sticky; top:0; z-index:100; padding: .9rem 0; transition: background var(--dur-med), border-color var(--dur-med), backdrop-filter var(--dur-med); border-bottom:1px solid transparent; }
.site-header.is-scrolled{ background: rgba(5,4,9,.72); backdrop-filter: blur(16px) saturate(140%); border-bottom-color: var(--line); }
.header-inner{ display:flex; align-items:center; justify-content:space-between; gap:1.5rem; }
.brand{ display:flex; align-items:center; gap:.5em; font-family: var(--f-display); font-weight:800; font-size:1.28rem; letter-spacing:-.02em; }
.brand-mark{ display:inline-grid; place-items:center; width:34px; height:34px; border-radius:10px; background: var(--g-primary); font-size:1rem; box-shadow: 0 6px 18px -4px rgba(82,82,91,.7); }
.main-nav{ display:flex; align-items:center; gap:2.1rem; }
.main-nav a{ position:relative; font-size:.92rem; font-weight:500; color: var(--ink-dim); padding:.3em 0; transition: color var(--dur-fast); }
.main-nav a::after{ content:""; position:absolute; left:0; right:100%; bottom:-4px; height:2px; background: var(--g-primary); border-radius:2px; transition: right var(--dur-med) var(--ease-out); }
.main-nav a:hover, .main-nav a.is-active{ color: var(--ink); }
.main-nav a:hover::after, .main-nav a.is-active::after{ right:0; }
.header-actions{ display:flex; align-items:center; gap:1rem; }
.nav-toggle{ display:none; width:38px; height:38px; border-radius:10px; border:1px solid var(--glass-border); background:var(--glass-bg); position:relative; }
.nav-toggle span, .nav-toggle span::before, .nav-toggle span::after{ content:""; position:absolute; left:9px; right:9px; height:2px; background: var(--ink); transition: transform .3s var(--ease-out), opacity .3s; }
.nav-toggle span{ top:18px; }
.nav-toggle span::before{ top:-7px; }
.nav-toggle span::after{ top:7px; }
.nav-toggle.is-open span{ background:transparent; }
.nav-toggle.is-open span::before{ transform: translateY(7px) rotate(45deg); }
.nav-toggle.is-open span::after{ transform: translateY(-7px) rotate(-45deg); }

@media (max-width: 880px){
  .main-nav{ position:fixed; inset: 64px 0 0 0; flex-direction:column; justify-content:flex-start; align-items:stretch; gap:0;
    background: rgba(6,5,12,.98); backdrop-filter: blur(20px); padding: 1rem var(--gutter) 2rem; transform: translateY(-8px); opacity:0; visibility:hidden; transition: all .35s var(--ease-out); border-top:1px solid var(--line); }
  .main-nav.is-open{ transform: translateY(0); opacity:1; visibility:visible; }
  .main-nav a{ padding: 1rem 0; border-bottom:1px solid var(--line-soft); font-size:1.1rem; }
  .header-actions .btn-gradient{ display:none; }
  .nav-toggle{ display:block; }
}

/* ---------- Footer ---------- */
.site-footer{ position:relative; border-top:1px solid var(--line); padding: 4.5rem 0 0; margin-top:6rem; background: linear-gradient(180deg, transparent, rgba(39,39,42,.05)); }
.footer-grid{ display:grid; grid-template-columns: 1.5fr 1fr 1fr 1.2fr; gap: 2.5rem; padding-bottom: 3rem; }
.footer-brand p{ color: var(--ink-faint); font-size:.92rem; margin-top:.9rem; max-width: 30ch; }
.footer-col h4{ font-family: var(--f-display); font-size:.85rem; letter-spacing:.06em; text-transform:uppercase; color: var(--ink-dim); margin-bottom:1.1rem; }
.footer-col ul{ display:flex; flex-direction:column; gap:.7rem; }
.footer-col a{ font-size:.9rem; color: var(--ink-faint); transition: color var(--dur-fast); }
.footer-col a:hover{ color: var(--cyan); }
.footer-newsletter{ display:flex; gap:.5rem; margin-top:.8rem; }
.footer-newsletter input{ flex:1; min-width:0; padding:.75em 1em; border-radius:10px; border:1px solid var(--glass-border); background: var(--glass-bg); font-size:.85rem; }
.footer-bar{ display:flex; align-items:center; justify-content:space-between; gap:1rem; flex-wrap:wrap; padding: 1.6rem 0; border-top:1px solid var(--line); font-size:.82rem; color: var(--ink-faint); }
.footer-bar a{ color: var(--ink-faint); }
.footer-bar a:hover{ color: var(--ink); }
.footer-legal-links{ display:flex; gap:1.4rem; flex-wrap:wrap; }
@media (max-width: 900px){ .footer-grid{ grid-template-columns: 1fr 1fr; } }
@media (max-width: 560px){ .footer-grid{ grid-template-columns: 1fr; } }

/* ---------- Success modal ---------- */
.success-modal{ position:fixed; inset:0; z-index:300; display:grid; place-items:center; padding:1.25rem; background:rgba(0,0,0,.68); opacity:0; visibility:hidden; transition:opacity var(--dur-med) var(--ease-out), visibility var(--dur-med); }
.success-modal.is-open{ opacity:1; visibility:visible; }
.success-modal-card{ position:relative; width:min(410px, calc(100vw - 2.5rem)); min-width:0; padding:2.5rem 2rem 1.8rem; overflow:hidden; text-align:center; background:linear-gradient(160deg, rgba(255,255,255,.12), rgba(255,255,255,.035)), var(--bg-card); border:1px solid var(--glass-border); border-radius:var(--radius-md); box-shadow:0 28px 80px rgba(0,0,0,.55), 0 1px 0 rgba(255,255,255,.14) inset; transform:translateY(18px) scale(.96); transition:transform var(--dur-med) var(--ease-spring); }
.success-modal.is-open .success-modal-card{ transform:translateY(0) scale(1); }
.success-modal-card::before{ content:""; position:absolute; left:15%; right:15%; top:0; height:2px; background:var(--g-warm); box-shadow:0 0 24px rgba(113,113,122,.8); }
.success-modal-close{ position:absolute; top:.75rem; right:.75rem; width:2rem; height:2rem; border:1px solid var(--glass-border); border-radius:50%; color:var(--ink-dim); font-size:1.25rem; line-height:1; transition:color var(--dur-fast), background var(--dur-fast); }
.success-modal-close:hover{ color:var(--ink); background:var(--glass-bg-hi); }
.success-modal-icon{ width:64px; height:64px; display:grid; place-items:center; margin:0 auto 1.25rem; border-radius:50%; background:var(--g-warm); color:#fff; box-shadow:0 10px 28px rgba(113,113,122,.35); }
.success-modal-icon svg{ width:30px; height:30px; }
.success-modal-card h2{ font-size:1.35rem; }
.success-modal-card p{ max-width:31ch; margin:.65rem auto 1.5rem; color:var(--ink-dim); font-size:.86rem; line-height:1.65; }
.success-modal-actions{ display:flex; justify-content:center; align-items:center; flex-wrap:wrap; gap:1rem; padding-top:1.1rem; border-top:1px solid var(--line); }
.success-modal-actions .btn-gradient, .success-modal-actions .btn-ghost{ font-size:.76rem; padding:.7em 1.15em; }
.success-confetti{ position:absolute; width:4px; height:4px; border-radius:1px; background:var(--orange); opacity:.7; transform:rotate(28deg); }
.success-confetti:nth-of-type(1){ top:18%; left:22%; }
.success-confetti:nth-of-type(2){ top:27%; right:20%; width:3px; height:7px; background:var(--cyan); transform:rotate(-35deg); }
.success-confetti:nth-of-type(3){ top:12%; right:32%; width:3px; height:3px; background:var(--magenta); }
.success-confetti:nth-of-type(4){ top:31%; left:31%; width:3px; height:6px; background:var(--yellow); transform:rotate(55deg); }
@media (max-width: 420px){
  .success-modal-card{ padding-inline:1.25rem; }
  .success-modal-actions{ gap:.5rem; }
}

/* ==========================================================================
   AD EMBED LAYOUT UTILITIES
   (creative styling for each ad unit lives in ads.css; these just place them)
   ========================================================================== */
.ad-rail{ display:flex; justify-content:center; }
.ad-rail--full{ width:100%; }
.ad-sticky{ position:sticky; top: 6.5rem; }

/* ---------- Scroll reveal ---------- */
/* Reveal-on-scroll only hides content once we know JS is running (html.js
   is added by an inline script in <head>, before first paint). If JS fails
   or is blocked, [data-reveal] elements are never hidden in the first place —
   content stays visible with no animation, instead of disappearing. */
.js [data-reveal]{ opacity:0; transform: translateY(28px); transition: opacity .8s var(--ease-out), transform .8s var(--ease-out); }
[data-reveal].in-view{ opacity:1; transform: translateY(0); }
[data-reveal="fade"]{ transform:none; }
.js [data-reveal="left"]{ transform: translateX(-32px); }
[data-reveal="left"].in-view{ transform: translateX(0); }
.js [data-reveal="right"]{ transform: translateX(32px); }
[data-reveal="right"].in-view{ transform: translateX(0); }
.js [data-reveal="scale"]{ transform: scale(.92); }
[data-reveal="scale"].in-view{ transform: scale(1); }

/* ---------- Back to top ---------- */
.back-to-top{ position:fixed; right:1.4rem; bottom:1.4rem; z-index:80; width:46px; height:46px; border-radius:50%;
  background: var(--g-primary); display:grid; place-items:center; box-shadow: 0 12px 30px -8px rgba(82,82,91,.6);
  opacity:0; visibility:hidden; transform: translateY(10px); transition: all var(--dur-med) var(--ease-out); }
.back-to-top.is-visible{ opacity:1; visibility:visible; transform:translateY(0); }

/* ---------- Utility ---------- */
.text-center{ text-align:center; }
.mx-auto{ margin-inline:auto; }
.mt-1{ margin-top:1rem; } .mt-2{ margin-top:2rem; } .mt-3{ margin-top:3rem; }
.mb-1{ margin-bottom:1rem; } .mb-2{ margin-bottom:2rem; } .mb-3{ margin-bottom:3rem; }
.sr-only{ position:absolute; width:1px; height:1px; overflow:hidden; clip:rect(0,0,0,0); white-space:nowrap; }
.section-pad{ padding: clamp(4rem, 9vw, 8rem) 0; }
.section-pad-sm{ padding: clamp(2.5rem, 5vw, 4.5rem) 0; }
.divider{ height:1px; background: linear-gradient(90deg, transparent, var(--line), transparent); }
.kicker{ font-family: var(--f-display); font-weight:700; font-size: clamp(1.9rem, 4vw, 2.9rem); letter-spacing:-.02em; }