/* ===============================
   INTERVAL PULSE 3.1
   Institutional Typography System
================================== */

@font-face {
  font-family: 'InterVar';
  src: url('../fonts/InterVariable.woff2') format('woff2');
  font-weight: 100 900;
  font-display: swap;
}

/* RESET */

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: 'InterVar', sans-serif;
  font-feature-settings: "liga" 1, "kern" 1;
  background:
    radial-gradient(circle at 50% 42%, #ffffff 0%, #f3f4f6 55%, #e9ebef 100%);
  color: #0f0f10;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* =====================================
   ATMOSPHERIC FIELD
===================================== */

.field {
  position: fixed;
  inset: 0;
  background:
    radial-gradient(circle at 50% 45%,
      rgba(0,0,0,0.035),
      transparent 60%);
  pointer-events: none;
}

/* =====================================
   GRID — LARGE SCALE
===================================== */

.grid {
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(0,0,0,0.01) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,0,0,0.01) 1px, transparent 1px);
  background-size: 420px 420px;
  pointer-events: none;
}

/* =====================================
   AXIS — DOES NOT CUT BRAND
===================================== */

.axis {
  position: fixed;
  top: 160px;
  bottom: 0;
  left: 50%;
  width: 1px;
  background: linear-gradient(
    to bottom,
    rgba(0,0,0,0.25),
    rgba(0,0,0,0.08)
  );
  transform: translateX(-50%);
  pointer-events: none;
  opacity: 0.45;
  transition: opacity 1.2s cubic-bezier(0.65, 0, 0.35, 1);
}

body.sound-active .axis {
  opacity: 0.9;
}

/* =====================================
   BRAND — MONOLITHIC
===================================== */

.brand {
  position: fixed;
  top: 52px;
  left: 50%;
  transform: translateX(-50%);
  font-size: clamp(28px, 3.5vw, 64px);
  font-weight: 240;
  letter-spacing: clamp(0.12em, 0.3vw, 0.18em);
  text-align: center;
  line-height: 1.1;
}


/* =====================================
   STAGE
===================================== */

.stage {
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

/* =====================================
   SYMBOL
===================================== */

.symbol {
  display: flex;
  align-items: center;
  gap: clamp(60px, 8vw, 160px);
}

.line {
  width: clamp(240px, 34vw, 620px);
  height: 1px;
  background: #0f0f10;
}

.core {
  width: clamp(48px, 6vw, 160px);
  height: clamp(48px, 6vw, 160px);
  border-radius: 50%;
  background: #0f0f10;
  animation: breathe 24s infinite cubic-bezier(0.65, 0, 0.35, 1);
}

@keyframes breathe {
  0%   { transform: scale(0.94); }
  50%  { transform: scale(1.08); }
  100% { transform: scale(0.94); }
}

/* =====================================
   PORTAL — ENTRY COMMAND
===================================== */

.portal {
  margin-top: 120px;
  font-size: clamp(16px, 1.2vw, 20px);
  font-weight: 500;
  letter-spacing: 0.55em;
  cursor: pointer;
  opacity: 0.55;
  transition:
    opacity 0.4s ease,
    letter-spacing 0.6s cubic-bezier(0.65,0,0.35,1);
}

.portal:hover {
  opacity: 1;
  letter-spacing: 0.65em;
}

/* =====================================
   CONTROLS
===================================== */

.controls {
  position: fixed;
  bottom: 48px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 80px;
}

.controls button {
  background: none;
  border: none;
  font-size: 13px;
  font-weight: 400;
  letter-spacing: 0.45em;
  cursor: pointer;
  opacity: 0.55;
  transition: opacity 0.3s ease;
}

.controls button:hover {
  opacity: 1;
}

/* =====================================
   RESPONSIVE TUNING
===================================== */

@media (max-width: 768px) {

  .brand {
    font-size: clamp(22px, 6vw, 42px);
    letter-spacing: 0.1em;
  }

  .axis {
    top: 120px;
  }

  .symbol {
    gap: 40px;
  }

  .controls {
    gap: 40px;
    bottom: 36px;
  }

  .portal {
    margin-top: 80px;
  }
}