.icon-404 {
  display: flex;
  justify-content: center;
  align-items: center;
  margin-bottom: 18px;
  animation: icon-pop 1.1s cubic-bezier(.22,1,.36,1);
  filter: drop-shadow(0 4px 16px rgba(60,72,88,0.10));
}

@keyframes icon-pop {
  0% { transform: scale(0.7) rotate(-8deg); opacity: 0; }
  60% { transform: scale(1.1) rotate(3deg); opacity: 1; }
  100% { transform: scale(1) rotate(0); opacity: 1; }
}

body {
  min-height: 100vh;
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  background: linear-gradient(120deg, #f7f8fa 0%, #e3e6ea 100%) url('data:image/svg+xml,%3Csvg width="40" height="40" viewBox="0 0 40 40" fill="none" xmlns="http://www.w3.org/2000/svg"%3E%3Crect width="40" height="40" fill="%23f7f8fa"/%3E%3Ccircle cx="20" cy="20" r="1.5" fill="%23e3e6ea"/%3E%3C/svg%3E') repeat;
  font-family: 'Inter', 'Segoe UI', Arial, sans-serif;
  display: flex;
  align-items: center;
  justify-content: center;
}

.container {
  background: rgba(255,255,255,0.85);
  box-shadow: 0 12px 40px rgba(60,72,88,0.16), 0 2px 8px rgba(60,72,88,0.10);
  border-radius: 32px;
  padding: 56px 40px 44px 40px;
  max-width: 440px;
  width: 94vw;
  text-align: center;
  margin: 36px 0;
  backdrop-filter: blur(6px) saturate(1.2);
  border: 1.5px solid rgba(227,230,234,0.45);
  transition: box-shadow 0.25s;
}

.container:hover {
  box-shadow: 0 16px 56px rgba(60,72,88,0.22), 0 4px 16px rgba(60,72,88,0.12);
}

.oops-wrapper {
  display: flex;
  justify-content: center;
  align-items: flex-end;
  font-size: clamp(3.2rem, 10vw, 6rem);
  font-weight: 900;
  letter-spacing: 0.09em;
  color: #232946;
  margin-bottom: 18px;
  user-select: none;
  text-shadow: 0 4px 24px rgba(60,72,88,0.10);
}

.oops-letter, .oops-exclamation {
  opacity: 0;
  transform: translateY(-80px) scale(0.9);
  transition: opacity 0.3s, transform 0.6s cubic-bezier(.22,1,.36,1);
  display: inline-block;
  text-shadow: 0 2px 12px rgba(60,72,88,0.10);
}

.oops-letter.visible {
  opacity: 1;
  transform: translateY(0) scale(1.04);
  animation: letter-bounce 0.7s cubic-bezier(.22,1,.36,1);
}

@keyframes letter-bounce {
  0% { transform: translateY(-80px) scale(0.9); }
  60% { transform: translateY(10px) scale(1.08); }
  80% { transform: translateY(-4px) scale(1.02); }
  100% { transform: translateY(0) scale(1.04); }
}

.oops-exclamation {
  color: #f25f4c;
  margin-left: 0.1em;
  animation: exclamation-pulse 1.2s infinite alternate cubic-bezier(.68,-0.55,.27,1.55);
}

.oops-exclamation.visible {
  opacity: 1;
  transform: translateY(0) scale(1.13);
}

@keyframes exclamation-pulse {
  0% { transform: scale(1.13); filter: brightness(1); }
  100% { transform: scale(1.28); filter: brightness(1.2); }
}

.message {
  font-size: 1.18rem;
  color: #3d4250;
  margin-bottom: 36px;
  margin-top: 0;
  line-height: 1.6;
  font-weight: 500;
  letter-spacing: 0.01em;
}

.button-group {
  display: flex;
  gap: 18px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  background: linear-gradient(90deg, #232946 60%, #3b3f5c 100%);
  color: #fff;
  padding: 0.95em 2.4em;
  border: none;
  border-radius: 999px;
  font-size: 1.08rem;
  font-weight: 700;
  box-shadow: 0 2px 12px rgba(60,72,88,0.10);
  cursor: pointer;
  text-decoration: none;
  transition: background 0.18s, color 0.18s, box-shadow 0.18s, transform 0.18s;
  outline: none;
  letter-spacing: 0.01em;
}

.btn:hover, .btn:focus {
  background: linear-gradient(90deg, #f25f4c 60%, #ff8c6b 100%);
  color: #fff;
  box-shadow: 0 6px 24px rgba(242,95,76,0.13);
  transform: translateY(-2px) scale(1.04);
}

.btn-outline {
  background: #fff;
  color: #232946;
  border: 2.5px solid #232946;
  font-weight: 700;
}

.btn-outline:hover, .btn-outline:focus {
  background: #f7f8fa;
  color: #f25f4c;
  border-color: #f25f4c;
  box-shadow: 0 4px 16px rgba(242,95,76,0.10);
}

@media (max-width: 600px) {
  .container {
    padding: 28px 4vw 18px 4vw;
    max-width: 99vw;
    border-radius: 18px;
  }
  .icon-404 {
    margin-bottom: 10px;
  }
  .oops-wrapper {
    font-size: clamp(2.1rem, 14vw, 3.5rem);
    margin-bottom: 10px;
  }
  .message {
    font-size: 1.01rem;
    margin-bottom: 22px;
  }
  .btn {
    padding: 0.7em 1.2em;
    font-size: 0.98rem;
  }
  .button-group {
    gap: 10px;
  }
}