Цель сброса стилей состоит в том, чтобы уменьшить разность отступов, размеров шрифтов заголовков и т.д. заданных по умолчанию в разных браузерах.
Решение от Eric Meyer v2.0.
html, body, div, span, applet, object, iframe,
h1, h2, h3, h4, h5, h6, p, blockquote, pre,
a, abbr, acronym, address, big, cite, code,
del, dfn, em, img, ins, kbd, q, s, samp,
small, strike, strong, sub, sup, tt, var,
b, u, i, center,
dl, dt, dd, ol, ul, li,
fieldset, form, label, legend,
table, caption, tbody, tfoot, thead, tr, th, td,
article, aside, canvas, details, embed,
figure, figcaption, footer, header, hgroup,
menu, nav, output, ruby, section, summary,
time, mark, audio, video {
margin: 0;
padding: 0;
border: 0;
font-size: 100%;
font: inherit;
vertical-align: baseline;
}
article, aside, details, figcaption, figure,
footer, header, hgroup, menu, nav, section {
display: block;
}
html {
height: 100%;
}
body {
line-height: 1;
}
ol, ul {
list-style: none;
}
blockquote, q {
quotes: none;
}
blockquote:before, blockquote:after,
q:before, q:after {
content: '';
content: none;
}
table {
border-collapse: collapse;
border-spacing: 0;
}
Сжатая версия:
html,body,div,span,applet,object,iframe,h1,h2,h3,h4,h5,h6,p,blockquote,pre,a,abbr,acronym,address,big,cite,code,del,dfn,em,img,ins,kbd,q,s,samp,small,strike,strong,sub,sup,tt,var,b,u,i,center,dl,dt,dd,ol,ul,li,fieldset,form,label,legend,table,caption,tbody,tfoot,thead,tr,th,td,article,aside,canvas,details,embed,figure,figcaption,footer,header,hgroup,menu,nav,output,ruby,section,summary,time,mark,audio,video{margin:0;padding:0;border:0;font-size:100%;font:inherit;vertical-align:baseline}
article,aside,details,figcaption,figure,footer,header,hgroup,menu,nav,section{display:block}
html{height:100%}
body{line-height:1}
ol,ul{list-style:none}
blockquote,q{quotes:none}
blockquote:before,blockquote:after,q:before,q:after{content:'';content:none}
table{border-collapse:collapse;border-spacing:0}
Более расширенный сброс стилей (присутствуют стили для IE, iOS, Safari).
https://necolas.github.io/normalize.css
/*! normalize.css v8.0.1 | MIT License | github.com/necolas/normalize.css */
html {
line-height: 1.15;
-webkit-text-size-adjust: 100%;
}
body {
margin: 0;
}
main {
display: block;
}
h1 {
font-size: 2em;
margin: 0.67em 0;
}
hr {
box-sizing: content-box;
height: 0;
overflow: visible;
}
pre {
font-family: monospace, monospace;
font-size: 1em;
}
a {
background-color: transparent;
}
abbr[title] {
border-bottom: none;
text-decoration: underline;
text-decoration: underline dotted;
}
b,strong {
font-weight: bolder;
}
code,kbd,samp {
font-family: monospace, monospace;
font-size: 1em;
}
small {
font-size: 80%;
}
sub,sup {
font-size: 75%;
line-height: 0;
position: relative;
vertical-align: baseline;
}
sub {
bottom: -0.25em;
}
sup {
top: -0.5em;
}
img {
border-style: none;
}
button,input,optgroup,select,textarea {
font-family: inherit;
font-size: 100%;
line-height: 1.15;
margin: 0;
}
button,input {
overflow: visible;
}
button,select {
text-transform: none;
}
button,[type="button"],[type="reset"],[type="submit"] {
-webkit-appearance: button;
}
button::-moz-focus-inner,
[type="button"]::-moz-focus-inner,
[type="reset"]::-moz-focus-inner,
[type="submit"]::-moz-focus-inner {
border-style: none;
padding: 0;
}
button:-moz-focusring,
[type="button"]:-moz-focusring,
[type="reset"]:-moz-focusring,
[type="submit"]:-moz-focusring {
outline: 1px dotted ButtonText;
}
fieldset {
padding: 0.35em 0.75em 0.625em;
}
legend {
box-sizing: border-box;
color: inherit;
display: table;
max-width: 100%;
padding: 0;
white-space: normal;
}
progress {
vertical-align: baseline;
}
textarea {
overflow: auto;
}
[type="checkbox"],[type="radio"] {
box-sizing: border-box;
padding: 0;
}
[type="number"]::-webkit-inner-spin-button,[type="number"]::-webkit-outer-spin-button {
height: auto;
}
[type="search"] {
-webkit-appearance: textfield;
outline-offset: -2px;
}
[type="search"]::-webkit-search-decoration {
-webkit-appearance: none;
}
::-webkit-file-upload-button {
-webkit-appearance: button;
font: inherit;
}
details {
display: block;
}
summary {
display: list-item;
}
template {
display: none;
}
[hidden] {
display: none;
}
Сжатая версия:
/*! normalize.css v3.0.1 | MIT License | git.io/normalize */
html{font-family:sans-serif;-ms-text-size-adjust:100%;-webkit-text-size-adjust:100%}
body{margin:0}
article,aside,details,figcaption,figure,footer,header,hgroup,main,nav,section,summary{display:block}
audio,canvas,progress,video{display:inline-block;vertical-align:baseline}
audio:not([controls]){display:none;height:0}
[hidden],template{display:none}
a{background:transparent}
a:active,a:hover{outline:0}
abbr[title]{border-bottom:1px dotted}
b,strong{font-weight:bold}
dfn{font-style:italic}
h1{font-size:2em;margin:0.67em 0}
mark{background:#ff0;color:#000}
small{font-size:80%}
sub,sup{font-size:75%;line-height:0;position:relative;vertical-align:baseline}
sup{top:-0.5em}
sub{bottom:-0.25em}
img{border:0}
svg:not(:root){overflow:hidden}
figure{margin:1em 40px}
hr{-moz-box-sizing:content-box;box-sizing:content-box;height:0}
pre{overflow:auto}
code,kbd,pre,samp{font-family:monospace,monospace;font-size:1em}
button,input,optgroup,select,textarea{color:inherit;font:inherit;margin:0}
button{overflow:visible}
button,select{text-transform:none}
button,html input[type="button"],input[type="reset"],input[type="submit"]{-webkit-appearance:button;cursor:pointer}
button[disabled],html input[disabled]{cursor:default}
button::-moz-focus-inner,input::-moz-focus-inner{border:0;padding:0}
input{line-height:normal}
input[type="checkbox"],input[type="radio"]{box-sizing:border-box;padding:0}
input[type="number"]::-webkit-inner-spin-button,input[type="number"]::-webkit-outer-spin-button{height:auto}
input[type="search"]{-webkit-appearance:textfield;-moz-box-sizing:content-box;-webkit-box-sizing:content-box;box-sizing:content-box}
input[type="search"]::-webkit-search-cancel-button,input[type="search"]::-webkit-search-decoration{-webkit-appearance:none}
fieldset{border:1px solid #c0c0c0;margin:0 2px;padding:0.35em 0.625em 0.75em}
legend{border:0;padding:0}
textarea{overflow:auto}
optgroup{font-weight:bold}
table{border-collapse:collapse;border-spacing:0}
td,th{padding:0}
Полно упрощенных вариантов, не советую тут тратить свое время