/* ── THEME TOKENS ── */
  :root.night {
    --bg: #06090C; --bg-soft: #0D1218; --bg-card: rgba(20,25,32,0.5);
    --ink-1: #F4F2EC; --ink-2: #A9ADB3; --ink-3: #6B7079; --ink-4: #3F444B;
    --accent: #7FE3C4; --accent-dim: #4A8F7B;
    --line: rgba(255,255,255,0.08); --grid-line: rgba(255,255,255,0.025);
    --vignette: rgba(6,9,12,0.85); --cursor-blend: screen;
    --fluid-tint-r: 0.498; --fluid-tint-g: 0.890; --fluid-tint-b: 0.768;
    --sphere-r: 0.498; --sphere-g: 0.890; --sphere-b: 0.768;
    --sphere-wire-opacity: 0.07; --fluid-display-mode: 0.0;
  }
  :root.day {
    --bg: #EDE6D6; --bg-soft: #E2D9C5; --bg-card: rgba(232,224,207,0.6);
    --ink-1: #1A1F1B; --ink-2: #4A4E48; --ink-3: #6F7268; --ink-4: #A8A498;
    --accent: #2D5F4E; --accent-dim: #1A3D32;
    --line: rgba(26,31,27,0.10); --grid-line: rgba(26,31,27,0.05);
    --vignette: rgba(237,230,214,0.5); --cursor-blend: multiply;
    --fluid-tint-r: 0.176; --fluid-tint-g: 0.373; --fluid-tint-b: 0.306;
    --sphere-r: 0.176; --sphere-g: 0.373; --sphere-b: 0.306;
    --sphere-wire-opacity: 0.18; --fluid-display-mode: 1.0;
  }

  *, *::before, *::after { box-sizing: border-box; }
  html, body {
    background: var(--bg); cursor: none;
    transition: background 1.4s cubic-bezier(0.2,0.8,0.2,1);
    overflow: hidden; height: 100%; margin: 0;
    scrollbar-width: none; -ms-overflow-style: none;
  }
  body { font-family: 'Inter', sans-serif; color: var(--ink-1); -webkit-font-smoothing: antialiased; }

  ::selection { background: var(--accent); color: var(--bg); }
  ::-webkit-scrollbar { width: 0; height: 0; }

  /* ── CURSOR ── */
  .cursor-dot {
    position: fixed; width: 6px; height: 6px; background: var(--accent);
    border-radius: 50%; pointer-events: none; z-index: 9999;
    transform: translate(-50%,-50%);
    transition: width .4s cubic-bezier(.2,.8,.2,1), height .4s cubic-bezier(.2,.8,.2,1), background 1.2s;
    mix-blend-mode: var(--cursor-blend);
  }
  .cursor-ring {
    position: fixed; width: 36px; height: 36px;
    border: 1px solid var(--accent); border-radius: 50%; opacity: .5;
    pointer-events: none; z-index: 9998; transform: translate(-50%,-50%);
    transition: width .5s cubic-bezier(.2,.8,.2,1), height .5s cubic-bezier(.2,.8,.2,1), border-color 1.2s;
  }
  .cursor-dot.hover { width: 14px; height: 14px; }
  .cursor-ring.hover { width: 64px; height: 64px; opacity: .9; }

  /* ── OVERLAYS ── */
  .grid-overlay {
    background-image: linear-gradient(var(--grid-line) 1px, transparent 1px),
                      linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
    background-size: 80px 80px;
    mask-image: radial-gradient(ellipse 90% 70% at 50% 40%, #000 20%, transparent 85%);
    -webkit-mask-image: radial-gradient(ellipse 90% 70% at 50% 40%, #000 20%, transparent 85%);
  }
  .vignette { background: radial-gradient(ellipse at center, transparent 30%, var(--vignette) 100%); }

  @keyframes scan {
    0%   { transform: translateY(-10vh); opacity: 0; }
    10%  { opacity: .45; } 90% { opacity: .45; }
    100% { transform: translateY(110vh); opacity: 0; }
  }
  .scan-line {
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--accent), transparent);
    animation: scan 24s linear infinite;
  }

  /* ── TYPOGRAPHY ── */
  .word { display: inline-block; white-space: nowrap; margin-right: .18em; }
  .word:last-child { margin-right: 0; }
  .char {
    display: inline-block; opacity: 0;
    transform: translateY(.4em) rotateX(-30deg); transform-origin: 50% 50% -20px;
    transition: opacity .7s cubic-bezier(.2,.8,.2,1), transform .9s cubic-bezier(.2,.8,.2,1);
  }
  .char.in { opacity: 1; transform: translateY(0) rotateX(0deg); }
  .fade-in {
    opacity: 0; transform: translateY(20px);
    transition: opacity 1.4s cubic-bezier(.2,.8,.2,1), transform 1.4s cubic-bezier(.2,.8,.2,1);
  }
  .fade-in.in { opacity: 1; transform: translateY(0); }

  .hero-headline {
    font-family: 'Inter', sans-serif; font-weight: 200;
    font-size: clamp(2.5rem, 8vw, 8rem); line-height: 1.0;
    letter-spacing: -.035em; color: var(--ink-1); margin: 0;
  }
  .hero-headline em { font-style: italic; font-weight: 300; color: var(--accent); }

  .pulse-dot {
    width: 6px; height: 6px; border-radius: 50%; background: var(--accent);
    animation: dot-pulse 2.2s ease-in-out infinite;
  }
  @keyframes dot-pulse {
    0%   { box-shadow: 0 0 0 0 color-mix(in srgb, var(--accent) 55%, transparent); }
    70%  { box-shadow: 0 0 0 10px color-mix(in srgb, var(--accent) 0%, transparent); }
    100% { box-shadow: 0 0 0 0 color-mix(in srgb, var(--accent) 0%, transparent); }
  }

  @keyframes pulse-down {
    0% { transform: translateY(-100%); opacity: 0; }
    50% { opacity: 1; }
    100% { transform: translateY(100%); opacity: 0; }
  }
  .scroll-pulse {
    width: 1px; height: 40px;
    background: linear-gradient(to bottom, transparent, var(--accent), transparent);
    animation: pulse-down 2.4s ease-in-out infinite;
  }

  /* ── THEME TOGGLE ── */
  .theme-toggle {
    width: 36px; height: 36px; border: 1px solid var(--line); border-radius: 50%;
    display: flex; align-items: center; justify-content: center; cursor: none;
    background: transparent; color: var(--ink-2); position: relative; overflow: hidden;
    transition: border-color .5s, transform .5s cubic-bezier(.2,.8,.2,1);
  }
  .theme-toggle:hover { border-color: var(--accent); color: var(--accent); transform: rotate(180deg); }
  .icon-stack { position: relative; width: 16px; height: 16px; }
  .icon-stack svg { position: absolute; inset: 0; transition: opacity .5s, transform .5s cubic-bezier(.2,.8,.2,1); }
  :root.night .icon-sun { opacity: 0; transform: scale(.5) rotate(-90deg); }
  :root.night .icon-moon { opacity: 1; transform: scale(1) rotate(0); }
  :root.day .icon-sun { opacity: 1; transform: scale(1) rotate(0); }
  :root.day .icon-moon { opacity: 0; transform: scale(.5) rotate(90deg); }

  /* ── SIGNAL CARD ── */
  .signal-card {
    border: 1px solid var(--line); background: transparent;
    transition: border-color .6s, background 1.4s, box-shadow .6s;
    padding: 2rem; border-radius: 6px;
  }
  .signal-card:hover {
    border-color: var(--accent);
    box-shadow: 0 0 0 1px color-mix(in srgb, var(--accent) 22%, transparent),
                0 12px 40px -12px color-mix(in srgb, var(--accent) 30%, transparent);
  }
  .signal-input {
    background: transparent;
    border: 1px solid var(--ink-4);
    color: var(--ink-1); transition: border-color .4s, box-shadow .4s, background .4s;
    flex: 1; padding: .875rem 1.1rem; font-family: 'JetBrains Mono', monospace; font-size: .875rem;
    border-radius: 4px;
  }
  .signal-input::placeholder { color: var(--ink-3); }
  .signal-input:focus {
    border-color: var(--accent); outline: none;
    background: color-mix(in srgb, var(--bg-soft) 85%, transparent);
    box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 16%, transparent);
  }
  .signal-button {
    border: 1px solid var(--accent); color: var(--accent); background: transparent;
    transition: all .4s cubic-bezier(.2,.8,.2,1); cursor: none;
    padding: .875rem 1.6rem; font-family: 'JetBrains Mono', monospace;
    font-size: .6875rem; letter-spacing: .2em; text-transform: uppercase; white-space: nowrap;
    border-radius: 4px; flex-shrink: 0;
  }
  .signal-button:hover {
    background: var(--accent); color: var(--bg); transform: translateY(-2px);
    box-shadow: 0 8px 24px -6px color-mix(in srgb, var(--accent) 55%, transparent);
  }

  @keyframes slow-rotate { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }
  .cipher-mark { animation: slow-rotate 60s linear infinite; }

  /* ── LAYOUT HELPERS ── */
  .fixed-full { position: fixed; inset: 0; width: 100%; height: 100%; }
  #fluid { z-index: 0; pointer-events: none; }
  #sphere { z-index: 10; pointer-events: none; }
  .content-layer { position: relative; z-index: 30; }
  .overlay-layer { position: fixed; inset: 0; z-index: 20; pointer-events: none; }
  .overlay-layer .grid-overlay { position: absolute; inset: 0; }
  .overlay-layer .scan-line { position: absolute; left: 0; right: 0; }
  .overlay-layer .vignette { position: absolute; inset: 0; }

  /* NAV */
  nav#nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 50;
    padding: 1.25rem 2.5rem; display: flex; justify-content: space-between; align-items: center;
    background: transparent;
  }
  .nav-logo { display: flex; align-items: center; gap: .75rem; }
  .nav-logo span { color: var(--ink-1); font-weight: 500; letter-spacing: -.02em; }
  .nav-right { display: flex; align-items: center; gap: 1.5rem; }
  .nav-link {
    font-family: 'JetBrains Mono', monospace; font-size: .6875rem;
    letter-spacing: .2em; text-transform: uppercase; color: var(--ink-2);
    text-decoration: none; transition: color .3s;
  }
  .nav-link:hover { color: var(--accent); }

  /* SECTIONS */
  .hero-section {
    position: relative; min-height: 100vh; min-height: 100svh;
    display: flex; align-items: center; justify-content: center;
    padding: 0 2.5rem;
  }
  .hero-inner { position: relative; max-width: 80rem; margin: 0 auto; width: 100%; text-align: center; }
  .hero-headline-wrap { margin-bottom: 3rem; }
  .hero-subline {
    font-family: 'JetBrains Mono', monospace; font-size: .75rem;
    letter-spacing: .3em; text-transform: uppercase; color: var(--accent);
    display: flex; align-items: center; justify-content: center; gap: .75rem;
  }
  .subline-bar { display: inline-block; width: 2rem; height: 1px; background: var(--accent-dim); }
  .scroll-hint-wrap {
    position: absolute; bottom: 2.5rem; left: 50%; transform: translateX(-50%);
    overflow: hidden; height: 2.5rem; border: none; background: transparent; padding: 0;
    cursor: none; transition: opacity .4s ease;
  }

  /* ── HERO SLIDE 3 — SIGNUP FORM (replaces subline when active) ── */
  .hero-form-wrap { display: none; max-width: 26rem; margin: 0 auto; }
  .hero-form-label {
    font-family: 'JetBrains Mono', monospace; font-size: .75rem;
    letter-spacing: .3em; text-transform: uppercase; color: var(--ink-3);
    display: flex; align-items: center; justify-content: center; gap: .75rem;
    margin-bottom: 1.5rem;
  }
  .signal-form { display: flex; flex-wrap: wrap; gap: .75rem; }
  .signal-success {
    display: none; color: var(--accent); font-family: 'JetBrains Mono', monospace;
    font-size: .875rem; letter-spacing: .1em; text-transform: uppercase;
    padding: .75rem 0; text-align: center;
  }

  /* FOOTER */
  footer {
    position: fixed; bottom: 0; left: 0; right: 0; z-index: 50;
    padding: 1.5rem 2.5rem;
    background: transparent;
  }
  .footer-spacer { height: 0; }
  .footer-inner { max-width: 80rem; margin: 0 auto; }
  .footer-top {
    display: grid; grid-template-columns: 1fr auto 1fr;
    align-items: center; gap: 1rem; margin-bottom: .9rem;
  }
  .footer-year {
    font-family: 'JetBrains Mono', monospace; font-size: .625rem;
    letter-spacing: .3em; text-transform: uppercase; color: var(--ink-4);
    justify-self: start;
  }
  .footer-socials { display: flex; align-items: center; gap: 1.25rem; justify-self: center; }
  .footer-social { color: var(--ink-4); text-decoration: none; transition: color .3s; display: flex; }
  .footer-social:hover { color: var(--accent); }
  .footer-brand {
    font-family: 'JetBrains Mono', monospace; font-size: .625rem;
    letter-spacing: .3em; text-transform: uppercase; color: var(--ink-4);
    justify-self: end;
  }
  .footer-bottom {
    border-top: 1px solid var(--line); padding-top: .9rem;
    display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: .75rem;
  }
  .footer-links { display: flex; align-items: center; gap: 1rem; }
  .footer-link {
    font-family: 'JetBrains Mono', monospace; font-size: .5625rem;
    letter-spacing: .2em; text-transform: uppercase; color: var(--ink-4); text-decoration: none;
    transition: color .3s;
  }
  .footer-link:hover { color: var(--accent); }
  .footer-sep { color: var(--ink-4); font-size: .5625rem; }
  .footer-copy {
    font-family: 'JetBrains Mono', monospace; font-size: .5625rem;
    letter-spacing: .15em; color: var(--ink-4);
  }

  /* ── RESPONSIVE ── */
  /* Touch/coarse-pointer devices (phones, tablets, touch laptops): kill the
     custom cursor regardless of screen width, since it never gets mousemove
     events and would otherwise sit frozen on-screen. */
  @media (hover: none), (pointer: coarse) {
    .cursor-dot, .cursor-ring { display: none; }
    body, .theme-toggle, .signal-button, .scroll-hint-wrap { cursor: auto; }
    a, button { cursor: pointer; }
  }
  @media (max-width: 1024px) {
    nav#nav { padding: 1.25rem 2rem; }
    .hero-section { padding: 0 2rem; }
  }
  @media (max-width: 768px) {
    .cursor-dot, .cursor-ring { display: none; }
    body, .theme-toggle, .signal-button, .scroll-hint-wrap { cursor: auto; }
    a, button { cursor: pointer; }
    nav#nav { padding: 1.25rem 1.5rem; }
    .hero-section { padding: 0 1.5rem; }
    .hero-headline-wrap { margin-bottom: 2rem; }
    .signal-input { min-width: 0; }
    .signal-button { padding: .875rem 1.1rem; font-size: .5625rem; letter-spacing: .12em; }
    .footer-top { grid-template-columns: 1fr; justify-items: center; gap: .75rem; text-align: center; }
    .footer-year, .footer-brand { justify-self: center; }
    .footer-bottom { flex-direction: column; gap: .6rem; text-align: center; }
    .footer-links { gap: .65rem; }
    .footer-link { font-size: .5rem; letter-spacing: .14em; }
  }
  @media (max-width: 420px) {
    .signal-button { padding: .75rem .8rem; font-size: .5rem; letter-spacing: .06em; }
  }
  /* Short/landscape viewports (phones in landscape, small laptop windows) */
  @media (max-height: 480px) {
    .hero-headline-wrap { margin-bottom: 1.25rem; }
    .hero-form-wrap { margin-top: .5rem; }
    .scroll-hint-wrap { bottom: 1rem; height: 1.5rem; }
  }
  /* Large / TV-class displays */
  @media (min-width: 1600px) {
    .hero-inner { max-width: 90rem; }
    nav#nav { padding: 1.75rem 3.5rem; }
    footer { padding: 2rem 3.5rem; }
  }

  @media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
      animation-duration: .01ms !important;
      animation-iteration-count: 1 !important;
      transition-duration: .01ms !important;
    }
  }