* {}                        /* Universal */
div {}                      /* Element */
.container {}               /* Class */
#main {}                    /* ID */
ul li {}                    /* Descendant */
div > p {}                  /* Child */
h1 + p {}                   /* Adjacent sibling */
a:hover {}                  /* Pseudo-class */
li:first-child {}           /* First child */
input:checked {}            /* Checked state */
p::before {}                /* Pseudo-element */
[disabled] {}               /* Attribute selector */
section:not(.active) {}     /* Negation pseudo-class */

width: 100px;
height: 50px;
padding: 10px 20px;
margin: 20px 0;
border: 1px solid #333;
border-radius: 8px;
box-sizing: border-box;
outline: 2px dashed #f00;

color: #222;
background: linear-gradient(90deg, #eee, #ccc);
background-image: url('img.png');
background-size: cover;
background-position: center;
background-repeat: no-repeat;
opacity: 0.8;

font-family: 'Roboto', Arial, sans-serif;
font-size: 1.2rem;
font-weight: bold;
line-height: 1.5;
text-align: center;
text-transform: uppercase;
letter-spacing: 2px;
word-spacing: 8px;
text-shadow: 1px 1px 2px #000;
white-space: nowrap;

display: flex;
flex-direction: row;
justify-content: space-between;
align-items: center;
flex-wrap: wrap;
gap: 16px;
align-content: flex-start;
order: 2;
flex: 1 1 200px;

display: grid;
grid-template-columns: repeat(3, 1fr);
grid-template-rows: auto 1fr 50px;
gap: 10px;
grid-column: 1 / 3;
grid-row: 2;
grid-area: header;
place-items: center;

position: relative;
top: 10px;
left: 20px;
z-index: 100;
float: right;
clear: both;
position: sticky;
right: 0;
bottom: 0;

transition: all 0.3s ease;
transition-property: background, color;
transform: scale(1.1) rotate(5deg) translateY(10px);
animation: fadein 1s linear infinite alternate;

@keyframes fadein {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@media (max-width: 600px) {
  .container { flex-direction: column; }
  .header { font-size: 1.5rem; }
}

@media (min-width: 1200px) {
  .container { max-width: 1200px; }
}

cursor: pointer;
overflow: hidden;
visibility: visible;
display: none;
user-select: none;
pointer-events: none;
box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);