HTML CSS
(quick & simple examples)
TEXT-SHADOW: X Y BLUR COLOR .glow { text-shadow: 0 0 10px #fff700; }
<p class="glow">GLOW!</p>
STACK MULTIPLE SHADOWS TO CREATE A STRONGER GLOW .stronk { text-shadow: 0 0 5px #fff700, 0 0 10px #fff700, 0 0 20px #fff700, 0 0 40px #fff700; }
<p class="stronk">GLOW!</p>
@keyframes flash { FROM RED from { text-shadow: 0 0 5px red, 0 0 10px red, 0 0 20px red, 0 0 40px red; }
TO BLUE to { text-shadow: 0 0 5px blue, 0 0 10px blue, 0 0 20px blue, 0 0 40px blue; } }
ATTACH KEYFRAMES .fglow { animation: flash 0.2s ease infinite alternate; }
<h1 class="fglow">RED ALERT</h1>