/* ========================== RESET ========================== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: "Inter", system-ui, -apple-system, BlinkMacSystemFont;
}

/* ========================== ROOT ========================== */
:root {
  --bg-dark: #05070d;
  --bg-mid: #0b1228;

  --royal-blue: #4f7cff;
  --royal-cyan: #22f2ff;
  --royal-pink: #ff3cac;

  --glass-light: rgba(255,255,255,0.14);
  --glass-dark: rgba(255,255,255,0.04);
}

/* ========================== BODY ========================== */
html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
}

body {
  background:
    radial-gradient(circle at top, #111c42, var(--bg-dark));
  color: white;
  perspective: 1400px;
}

/* ========================== ENERGY BACKGROUND ========================== */
.energy-field {
  position: fixed;
  inset: 0;
  background:
    radial-gradient(circle at 15% 25%, rgba(79,124,255,0.18), transparent 60%),
    radial-gradient(circle at 85% 60%, rgba(34,242,255,0.14), transparent 60%),
    radial-gradient(circle at 50% 95%, rgba(255,60,172,0.1), transparent 60%);
  animation: energyPulse 16s infinite alternate;
  z-index: -3;
}

@keyframes energyPulse {
  from { filter: hue-rotate(0deg); }
  to   { filter: hue-rotate(28deg); }
}

/* ========================== LIGHT SWEEP ========================== */
.lightning {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(120deg,
      transparent 45%,
      rgba(255,255,255,0.06) 50%,
      transparent 55%);
  animation: lightningMove 8s infinite;
  z-index: -2;
}

@keyframes lightningMove {
  from { transform: translateX(-130%); }
  to   { transform: translateX(130%); }
}

/* ========================== PARTICLES ========================== */
.particles {
  position: fixed;
  inset: 0;
  z-index: -1;
}

.particles span {
  position: absolute;
  width: 2px;
  height: 2px;
  background: var(--royal-cyan);
  opacity: 0.35;
  animation: drift linear infinite;
}

@keyframes drift {
  from { transform: translateY(110vh); }
  to   { transform: translateY(-110vh); }
}

/* ========================== SCENE ========================== */
.scene {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ========================== GLASS CARD ========================== */
.core {
  width: min(92%, 480px);
  padding: 52px 38px;
  background:
    linear-gradient(145deg, var(--glass-light), var(--glass-dark));
  backdrop-filter: blur(26px);
  border-radius: 30px;
  box-shadow:
    0 60px 160px rgba(0,0,0,0.8),
    inset 0 0 1px rgba(255,255,255,0.6);
  text-align: center;
  animation: coreEnter 1.9s ease forwards;
  transform-style: preserve-3d;
}

@keyframes coreEnter {
  from {
    opacity: 0;
    transform: translateY(90px) scale(0.94);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

/* ========================== LOGO ========================== */
.brand-logo {
  width: 180px;
  height: 180px;
  margin-bottom: 18px;
  filter:
    drop-shadow(0 0 14px rgba(79,124,255,0.9))
    drop-shadow(0 0 28px rgba(34,242,255,0.6));
}

/* ========================== TEXT ========================== */
.brand-name {
  font-size: clamp(2.1rem, 6vw, 2.7rem);
  font-weight: 900;
  letter-spacing: 2.5px;
  background:
    linear-gradient(90deg,
      var(--royal-blue),
      var(--royal-cyan),
      var(--royal-pink));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.subtitle {
  margin-top: 14px;
  font-size: 1.15rem;
  opacity: 0;
  animation: fadeIn 1.2s forwards;
  animation-delay: 1.1s;
}

.tagline {
  margin-top: 16px;
  font-size: 1rem;
  color: #c7d2fe;
  opacity: 0;
  animation: fadeIn 1.2s forwards;
  animation-delay: 1.9s;
}

/* ========================== PROGRESS ========================== */
.progress-shell {
  margin-top: 36px;
  height: 7px;
  background: rgba(255,255,255,0.2);
  border-radius: 10px;
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  width: 0;
  background:
    linear-gradient(90deg,
      var(--royal-blue),
      var(--royal-cyan),
      var(--royal-pink));
  animation: load 4s ease forwards;
  animation-delay: 2.6s;
}

@keyframes load {
  to { width: 100%; }
}

/* ========================== BUTTON ========================== */
.enter-btn {
  margin-top: 36px;
  width: 100%;
  padding: 16px;
  border-radius: 18px;
  border: none;
  background:
    linear-gradient(90deg,
      var(--royal-blue),
      var(--royal-cyan));
  color: white;
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  opacity: 0;
  animation: fadeIn 1s forwards;
  animation-delay: 4.3s;
  transition: transform .3s ease, box-shadow .3s ease;
}

.enter-btn:hover {
  transform: translateY(-3px) scale(1.04);
  box-shadow:
    0 24px 54px rgba(79,124,255,0.65),
    0 0 18px rgba(34,242,255,0.5);
}

/* ========================== FOOTER ========================== */
.footer {
  position: fixed;
  bottom: 18px;
  width: 100%;
  text-align: center;
  font-size: 0.85rem;
  opacity: 0.65;
}

/* ========================== COMMON ========================== */
@keyframes fadeIn {
  to { opacity: 1; }
}

/* ========================== MOBILE ========================== */
@media (max-width: 480px) {
  .core { padding: 38px 26px; }
  .subtitle { font-size: 1.05rem; }
}