/* Reset */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Segoe UI", sans-serif;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background 0.4s, color 0.4s;
}

/* Light + Dark themes */
body.light {
  background: linear-gradient(135deg, #f5f7fa, #e6ebf3);
  color: #333;
}

body.dark {
  background: linear-gradient(135deg, #1b1212, #0e0e0e);
  color: #f5f5f5;
}

/* Header */
header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 24px;
  background: rgba(255,255,255,0.15);
  backdrop-filter: blur(10px);
  box-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

header .logo {
  height: 40px;
}

header h1 {
  font-size: 1.4rem;
  font-weight: 600;
}

#themeToggle {
  background: rgba(255,255,255,0.2);
  border: none;
  padding: 8px 12px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 1rem;
  transition: background 0.3s;
}
#themeToggle:hover {
  background: rgba(255,255,255,0.35);
}

/* Main */
main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.card {
  padding: 30px;
  border-radius: 16px;
  text-align: center;
  max-width: 400px;
  width: 100%;
}

.glass {
  background: rgba(255,255,255,0.15);
  border: 1px solid rgba(255,255,255,0.2);
  backdrop-filter: blur(12px);
  box-shadow: 0 8px 20px rgba(0,0,0,0.25);
}

/* Inputs & Buttons */
.card label {
  display: block;
  margin-bottom: 8px;
  font-weight: 500;
}

.card input {
  width: 100%;
  padding: 12px;
  border: none;
  border-radius: 8px;
  margin-bottom: 15px;
  font-size: 1rem;
  outline: none;
}

button {
  background: #ffbf00;
  color: #1b1212;
  border: none;
  padding: 10px 16px;
  border-radius: 8px;
  font-size: 1rem;
  cursor: pointer;
  transition: transform 0.2s, background 0.2s;
}

button:hover {
  transform: translateY(-2px);
  background: #e6aa00;
}

#qrcode {
  margin: 20px auto;
}

.hidden {
  display: none;
}

/* Footer */
footer {
  text-align: center;
  padding: 12px;
  font-size: 0.9rem;
  opacity: 0.7;
}