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

body {
  font-family: 'Courier New', Courier, monospace;
  background: radial-gradient(circle at center, #1a1a1a 0%, #000);
  color: #f0f0f0;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
}

.upload-box {
  background: rgba(30, 30, 30, 0.85);
  border: 2px solid #ccc;
  border-radius: 20px;
  box-shadow:
    0 0 15px #ccc,
    inset 0 0 40px rgba(255, 255, 255, 0.1);
  padding: 45px 50px;
  text-align: center;
  width: 100%;
  max-width: 420px;
  animation: glowPulse 2.5s infinite alternate;
  backdrop-filter: blur(6px);
}

.upload-box h1 {
  font-size: 2.25rem;
  margin-bottom: 30px;
  color: #fff;
  text-shadow:
    0 0 6px #fff,
    0 0 15px #ccc,
    0 0 30px #aaa,
    0 0 40px #888;
  letter-spacing: 0.05em;
  font-weight: 900;
  user-select: none;
  animation: flicker 3s infinite alternate ease-in-out;
}

.custom-file-input {
  display: none;
}

.custom-file-label {
  display: inline-block;
  background: #111;
  color: #f0f0f0;
  border: 2px solid #aaa;
  border-radius: 8px;
  padding: 12px 26px;
  font-size: 1rem;
  cursor: pointer;
  box-shadow:
    0 0 12px #888,
    inset 0 0 8px #222;
  transition: all 0.3s ease;
  margin-bottom: 20px;
  text-transform: uppercase;
  font-weight: 700;
}

.custom-file-label:hover {
  background-color: #e0e0e0;
  color: #111;
  box-shadow:
    0 0 24px #ccc,
    inset 0 0 18px #222;
  transform: scale(1.03);
}

.file-name {
  font-size: 0.9rem;
  margin-top: 8px;
  color: #ccc;
  text-shadow: 0 0 8px rgba(255, 255, 255, 0.2);
  user-select: none;
}

input[type="submit"] {
  background: transparent;
  color: #f0f0f0;
  border: 2.5px solid #ccc;
  padding: 14px 36px;
  font-size: 1.15rem;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.35s ease;
  box-shadow:
    0 0 14px #ccc,
    inset 0 0 10px #aaa;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

input[type="submit"]:hover {
  background-color: #e0e0e0;
  color: #111;
  box-shadow:
    0 0 30px #ccc,
    inset 0 0 18px #222;
  transform: scale(1.05);
}

.fade-in {
  opacity: 0;
  animation: fadeIn 1.5s ease-in-out forwards;
}

@keyframes fadeIn {
  to {
    opacity: 1;
  }
}

@keyframes glowPulse {
  0% {
    box-shadow: 0 0 15px #aaa, inset 0 0 40px rgba(200, 200, 200, 0.3);
  }
  100% {
    box-shadow: 0 0 30px #ccc, inset 0 0 60px rgba(220, 220, 220, 0.4);
  }
}

@keyframes flicker {
  0%, 19%, 21%, 23%, 25%, 54%, 56%, 100% {
    opacity: 1;
    text-shadow:
      0 0 6px #fff,
      0 0 15px #ccc,
      0 0 30px #aaa,
      0 0 40px #888;
  }
  20%, 22%, 24%, 55% {
    opacity: 0.85;
    text-shadow: none;
  }
}