Создание стилей подсказок типа WhatsApp

.arrow {
  --a: 15px; /* control the arrow shape */

  width: 200px;
  height: 100px;
  position: relative;
  overflow: hidden;
  background: red;
  border-radius: 10px;
  
  padding-left: var(--a); /* or padding-right */
  clip-path:polygon(0 0,100% 0,100% 100%,var(--a) 100%,var(--a) var(--a))
  /* x,y --> update all the x to (100% - x) to get the right */
}

                                <div class = "arrow">
                                  contents
                                </div>

.bubble {
  --r: 25px; /* the radius */
  --t: 30px; /* the size of the tail */
  
  max-width: 300px;
  padding: calc(2*var(--r)/3);
  -webkit-mask: 
    radial-gradient(var(--t) at var(--_d) 0,#0000 98%,#000 102%) 
      var(--_d) 100%/calc(100% - var(--r)) var(--t) no-repeat,
    conic-gradient(at var(--r) var(--r),#000 75%,#0000 0) 
      calc(var(--r)/-2) calc(var(--r)/-2) padding-box, 
    radial-gradient(50% 50%,#000 98%,#0000 101%) 
      0 0/var(--r) var(--r) space padding-box;
  background: #1384C5;
  color: #fff;
}
.left {
  --_d: 0%;
  border-left: var(--t) solid #0000;
  margin-right: var(--t);
  place-self: start;
}
.right {
  --_d: 100%;
  border-right: var(--t) solid #0000;
  margin-left: var(--t);
  place-self: end;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-content: center;
  gap: 20px;
  font-family: system-ui, sans-serif;
  font-size: 20px;
}

<div class = "bubble left">Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt </div>
<div class = "bubble right">Ok, Thank you</div>
<div class = "bubble left"> ut labore et dolore magna </div>
<div class = "bubble right">Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt </div>