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

body {
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: url('../img/ui/logo.png') no-repeat center center/cover;
    position: relative;
}

/* Capa oscura para que resalte el formulario */
body::before {
    content: '';
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: rgba(10, 10, 15, 0.65);
    backdrop-filter: blur(4px);
    z-index: 1;
}

.contenedor-login {
    position: relative;
    z-index: 2;
    width: 100%;
    max-width: 450px;
    padding: 20px;
}

/* Efecto Vidrio Borroso (Glassmorphism) con borde neón */
.caja-cristal {
    background: rgba(30, 32, 45, 0.6);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid rgba(0, 255, 200, 0.3);
    border-radius: 20px;
    padding: 40px 30px;
    box-shadow: 0 0 30px rgba(0, 0, 0, 0.8), inset 0 0 15px rgba(255, 0, 255, 0.15);
    color: #fff;
    transition: transform 0.3s ease;
}

.caja-cristal h2 {
    text-align: center;
    margin-bottom: 25px;
    font-size: 24px;
    letter-spacing: 2px;
    color: #00ffc8;
    text-transform: uppercase;
    text-shadow: 0 0 10px rgba(0, 255, 200, 0.5);
}

.grupo-input {
    margin-bottom: 20px;
    position: relative;
}

.grupo-input label {
    display: block;
    font-size: 13px;
    color: #a0a5c0;
    margin-bottom: 6px;
}

.grupo-input input {
    width: 100%;
    padding: 12px 15px;
    background: rgba(15, 16, 25, 0.7);
    border: 1px solid #4a4e69;
    border-radius: 10px;
    color: #fff;
    font-size: 14px;
    outline: none;
    transition: all 0.3s ease;
}

.grupo-input input:focus {
    border-color: #00ffc8;
    box-shadow: 0 0 10px rgba(0, 255, 200, 0.3);
}

/* Botones mamalones */
.btn-submit {
    width: 100%;
    padding: 14px;
    background: linear-gradient(45deg, #00ffc8, #00b8ff);
    border: none;
    border-radius: 10px;
    color: #000;
    font-weight: bold;
    font-size: 16px;
    cursor: pointer;
    margin-top: 10px;
    transition: all 0.3s ease;
    box-shadow: 0 0 15px rgba(0, 255, 200, 0.4);
}

.btn-submit:hover {
    background: linear-gradient(45deg, #ff007f, #9d00ff);
    color: #fff;
    box-shadow: 0 0 20px rgba(255, 0, 127, 0.6);
    transform: translateY(-2px);
}

.cambiar-form {
    text-align: center;
    margin-top: 20px;
    font-size: 14px;
}

.cambiar-form a {
    color: #00ffc8;
    text-decoration: none;
    font-weight: bold;
    cursor: pointer;
    transition: color 0.3s;
}

.cambiar-form a:hover {
    color: #ff007f;
}

.alerta {
    padding: 10px;
    border-radius: 8px;
    margin-bottom: 15px;
    text-align: center;
    font-size: 14px;
}
.alerta.error { background: rgba(255, 0, 0, 0.3); border: 1px solid red; }
.alerta.exito { background: rgba(0, 255, 0, 0.3); border: 1px solid green; }