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

/* FONDO */
body {
  min-height: 100vh;
  background: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
  display: flex;
  justify-content: center;
  align-items: center;
  color: #fff;
  padding-bottom: 50px;
}

/* CONTENEDOR */
.container {
  width: 100%;
  display: flex;
  justify-content: center;
}

/* LOGIN BOX */
.login-box {
  background: rgba(255, 255, 255, 0.08);
  padding: 35px 30px;
  width: 350px;
  border-radius: 14px;
  box-shadow: 0 15px 30px rgba(0,0,0,0.4);
  backdrop-filter: blur(10px);
  animation: fadeIn 0.8s ease;
}

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

/* TEXTO AYUDA */
.hint {
  background: rgba(0, 0, 0, 0.3);
  padding: 10px;
  border-radius: 8px;
  font-size: 14px;
  text-align: center;
  margin-bottom: 15px;
  line-height: 1.4;
}

/* TITULO */
.login-box h2 {
  text-align: center;
  margin-bottom: 25px;
  font-weight: 600;
}

/* INPUT GROUP */
.input-group {
  position: relative;
  margin-bottom: 22px;
}

.input-group input {
  width: 100%;
  padding: 10px 10px;
  background: transparent;
  border: none;
  border-bottom: 2px solid #ccc;
  color: #fff;
  font-size: 16px;
  outline: none;
  transition: 0.3s;
}

.input-group label {
  position: absolute;
  top: 50%;
  left: 0;
  transform: translateY(-50%);
  color: #ccc;
  pointer-events: none;
  transition: 0.3s;
}

/* EFECTOS INPUT */
.input-group input:focus,
.input-group input:valid {
  border-bottom-color: #00e6e6;
}

.input-group input:focus + label,
.input-group input:valid + label {
  top: -8px;
  font-size: 12px;
  color: #00e6e6;
}

/* BTN */
button {
  width: 100%;
  padding: 12px;
  border: none;
  border-radius: 8px;
  background: linear-gradient(135deg, #00c6ff, #0072ff);
  color: #fff;
  font-size: 16px;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
}

button:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.4);
}

/* MENSAJE ERROR */
#mensaje {
  margin-top: 15px;
  text-align: center;
  font-size: 14px;
}

/* FOOTER */
footer {
  position: fixed;
  bottom: 0;
  width: 100%;
  text-align: center;
  background: rgba(0, 0, 0, 0.4);
  padding: 10px 0;
  font-size: 14px;
  color: #ccc;
}