body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  margin: 0;
  background: linear-gradient(
    0deg,
    #00b8a9,
    #009688,
    #00acc1,
    #00838f,
    #00c2cb,
    #26c6da,
    #00acc1
  );
  background-size: 100% 800%;
  color: #222;
  min-height: 100vh;
  overflow-x: hidden;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 2rem;
  animation: shimmer 20s linear infinite;
  position: relative;
}

@keyframes shimmer {
  0% {
    background-position: 0% 100%;
  }
  100% {
    background-position: 0% 0%;
  }
}

body::before {
  content: "";
  position: fixed;
  top: 10px;
  left: 10px;
  right: 10px;
  bottom: 10px;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-radius: 16px;
  background: linear-gradient(135deg, rgba(255,255,255,0.1), rgba(255,255,255,0));
  box-shadow:
    0 0 20px rgba(255, 255, 255, 0.2),
    inset 0 0 10px rgba(255, 255, 255, 0.1);
  pointer-events: none;
  z-index: 999;
}

.container {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 16px;
  box-shadow: 0 8px 32px rgba(0, 180, 216, 0.3);
  max-width: 700px;
  width: 100%;
  padding: 3rem 3rem 5rem 3rem;
  position: relative;
  overflow: hidden;
  animation: fadeIn 1.5s ease forwards;
  min-height: 140vh; /* give more vertical space */
  z-index: 1;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

header h1 {
  font-weight: 700;
  font-size: 2.5rem;
  margin-bottom: 0.3rem;
  letter-spacing: 0.04em;
  color: #ffffff;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
  animation: floaty 4s ease-in-out infinite;
}

@keyframes floaty {
  0% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
  100% { transform: translateY(0); }
}

header p {
  font-weight: 400;
  font-size: 1.2rem;
  color: #e2f7ff;
  margin-top: 0;
  text-shadow: 0 1px 1px rgba(0, 0, 0, 0.15);
}

.btn {
  display: inline-block;
  background: linear-gradient(135deg, rgba(108, 193, 255, 0.6), rgba(0, 91, 191, 0.7));
  color: white;
  text-decoration: none;
  padding: 0.75rem 1.5rem;
  border-radius: 24px;
  font-weight: 700;
  transition: all 0.35s ease;
  box-shadow: 0 4px 16px rgba(0, 191, 255, 0.5),
              inset 0 0 12px rgba(255, 255, 255, 0.2);
  margin-top: 1rem;
  position: relative;
  z-index: 2;
}

.btn:hover {
  background: linear-gradient(135deg, rgba(0, 91, 191, 0.85), rgba(108, 193, 255, 0.85));
  box-shadow: 0 6px 20px rgba(108, 193, 255, 0.7),
              inset 0 0 18px rgba(255, 255, 255, 0.3);
  transform: translateY(-2px) scale(1.03);
}

.contact {
  margin-top: 4rem;
  padding-bottom: 5rem; /* give more space at bottom */
  position: relative;
  z-index: 2;
}

.bubbles {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  overflow: visible;
  z-index: 0;
}

.bubble {
  position: absolute;
  bottom: 0;
  left: var(--x);
  width: calc(var(--size) * 0.7);
  height: calc(var(--size) * 0.7);
  background: radial-gradient(circle at 30% 30%, rgba(255, 255, 255, 0.7), rgba(255, 255, 255, 0));
  border-radius: 50%;
  filter: drop-shadow(0 0 8px rgba(255, 255, 255, 0.4));
  animation: floatUp 10s ease-in-out infinite;
  animation-delay: var(--delay);
  transform-origin: center bottom;
  opacity: 0.75;
}

@keyframes floatUp {
  0% {
    transform: translateY(0) scale(1);
    opacity: 0.6;
  }
  50% {
    transform: translateY(-50%) scale(1.05);
    opacity: 0.9;
  }
  100% {
    transform: translateY(-100%) scale(1.1);
    opacity: 0;
  }
}

@keyframes pop {
  0% {
    transform: scale(1);
    opacity: 1;
  }
  50% {
    transform: scale(1.5);
    opacity: 0.6;
  }
  100% {
    transform: scale(0);
    opacity: 0;
  }
}

#achievement-container {
  position: fixed;
  bottom: 20px;
  right: 20px;
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 10px;
  pointer-events: none;
}

.achievement-popup {
  pointer-events: auto;
  background: #c0c0c0;
  border: 3px solid #000080;
  box-shadow:
    inset 2px 2px 5px #ffffff,
    inset -2px -2px 5px #000080;
  padding: 14px 22px;
  border-radius: 4px;
  width: 280px;
  font-family: Tahoma, Geneva, Verdana, sans-serif;
  font-size: 14px;
  color: #000080;
  user-select: none;
  animation: slideInFade 0.4s ease forwards, fadeOut 4s ease forwards 3s;
}

.achievement-popup .popup-title {
  font-weight: bold;
  margin-bottom: 6px;
  text-shadow: 1px 1px 0 #fff;
}

.achievement-popup .popup-message {
  line-height: 1.3;
}

@keyframes slideInFade {
  0% {
    opacity: 0;
    transform: translateX(100%);
  }
  100% {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes fadeOut {
  0% { opacity: 1; }
  100% { opacity: 0; }
}