:root {
  --bg: #f9f9f9;
  --nav: #0f172a;
  --accent-1: #2563eb;
  --accent-2: #1d4ed8;
  --muted: #6b7280;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Inter", system-ui, -apple-system, "Segoe UI", Roboto,
    "Helvetica Neue", Arial;
  background: var(--bg);
  color: #111827;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

header {
  background: var(--nav);
  color: #fff;
  padding: 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
}

nav a {
  color: #fff;
  margin: 0 1rem;
  text-decoration: none;
  font-weight: 600;
  transition: color 0.25s;
}

nav a:hover {
  color: #60a5fa;
}

main {
  padding-top: 76px;
}

/* leave space for fixed header */

.page {
  min-height: 80vh;
  padding: 2rem;
  display: none;
  opacity: 0;
  transform: translate(40px, 40px);
  transition: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.page.active {
  display: block;
  opacity: 1;
  transform: translate(0, 0);
}

.hero {
  background: white;
  padding: 2rem;
  border-radius: 12px;
  max-width: 920px;
  margin: 1.5rem auto;
  box-shadow: 0 8px 30px rgba(2, 6, 23, 0.06);
}

/* spinner overlay */
.spinner-overlay {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.88);
  z-index: 2000;
  opacity: 0;
  pointer-events: none;
  visibility: hidden;
  transition: opacity 0.28s ease, visibility 0.28s ease;
}

.spinner-overlay.active {
  opacity: 1;
  visibility: visible;
  pointer-events: all;
}

/* E spinner container */
.spinner-e {
  width: 110px;
  height: 110px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 20px;
  background: linear-gradient(
    180deg,
    rgba(29, 78, 216, 0.06),
    rgba(37, 99, 235, 0.04)
  );
  box-shadow: 0 8px 30px rgba(13, 27, 63, 0.08),
    inset 0 1px 0 rgba(255, 255, 255, 0.6);
  transform-origin: center;
  animation: e-rotate 1.4s linear infinite;
}

/* make the SVG scale slightly in and out for breathing */
@keyframes e-rotate {
  0% {
    transform: rotate(0deg) scale(0.98);
  }

  50% {
    transform: rotate(12deg) scale(1.02);
  }

  100% {
    transform: rotate(0deg) scale(0.98);
  }
}

/* SVG styling */
.spinner-e svg {
  width: 72px;
  height: 72px;
  display: block;
}

/* stroke draw + fade */
.e-path {
  stroke: url(#gradE);
  stroke-width: 6;
  stroke-linecap: round;
  stroke-linejoin: round;
  fill: none;
  stroke-dasharray: 160;
  stroke-dashoffset: 160;
  animation: e-draw 1.2s ease forwards, e-fade 1.8s linear infinite 0.6s;
}

/* shimmer sweep (using pseudo-mask) */
.e-shimmer {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
  border-radius: 20px;
}

.e-shimmer::after {
  content: "";
  position: absolute;
  left: -60%;
  top: 0;
  width: 60%;
  height: 100%;
  background: linear-gradient(
    90deg,
    rgba(255, 255, 255, 0),
    rgba(255, 255, 255, 0.5),
    rgba(255, 255, 255, 0)
  );
  transform: skewX(-20deg);
  animation: shimmer 1.4s ease-in-out infinite 0.3s;
}

.e-path {
  stroke-dasharray: 200;
  stroke-dashoffset: 200;
  animation: draw 2s infinite linear;
}

@keyframes draw {
  to {
    stroke-dashoffset: 0;
  }
}

@keyframes shimmer {
  0% {
    left: -60%;
    opacity: 0;
  }

  40% {
    left: 30%;
    opacity: 1;
  }

  100% {
    left: 120%;
    opacity: 0;
  }
}

@keyframes e-draw {
  to {
    stroke-dashoffset: 0;
  }
}

/* subtle fade pulse on the stroke */
@keyframes e-fade {
  0% {
    opacity: 1;
  }

  50% {
    opacity: 0.85;
  }

  100% {
    opacity: 1;
  }
}

/* small label under the E */
.spinner-label {
  margin-top: 10px;
  color: var(--muted);
  font-size: 13px;
  text-align: center;
}

/* responsive */
@media (max-width: 420px) {
  .spinner-e {
    width: 88px;
    height: 88px;
    border-radius: 16px;
  }

  .spinner-e svg {
    width: 58px;
    height: 58px;
  }
}