代码很简单：JSFiddle.

h2.titoloPagina::first-letter {
  color: #1d5987;
  display: block;
  float: left;
  font-family: Bell MT !important;
  font-size: 70px;
  /* margin-top: -15px;*/
  padding-right: 3px;
}
h2.titoloPagina span {
  border-bottom: 7px solid #1d5987;
  color: #538cc3;
  font-family: Bell MT !important;
  font-size: 30px !important;
  letter-spacing: 0;
  margin-left: 4px;
  padding-bottom: 5px;
}

/*! normalize.css v3.0.3 | MIT License | github.com/necolas/normalize.css */

/**
 * 1. Set default font family to sans-serif (opinionated).
 * 2. Prevent iOS and IE text size adjust after device orientation change,*    without disabling user zoom.
 */

html {
  font-family: sans-serif; /* 1 */
  -ms-text-size-adjust: 100%; /* 2 */
  -webkit-text-size-adjust: 100%; /* 2 */
}

/**
 * Remove default margin (opinionated).
 */

body {
  margin: 0;
}

/* HTML5 display definitions
   ========================================================================== */

/**
 * Correct `block` display not defined for any HTML5 element in IE 8/9.
 * Correct `block` display not defined for `details` or `summary` in IE 10/11
 * and Firefox.
 * Correct `block` display not defined for `main` in IE 11.
 */

article,aside,details,figcaption,figure,footer,header,main,menu,nav,section,summary {
  display: block;
}

/**
 * 1. Correct `inline-block` display not defined in IE 8/9.
 * 2. Normalize vertical alignment of `progress` in Chrome,Firefox,and Opera.
 */

audio,canvas,progress,video {
  display: inline-block; /* 1 */
  vertical-align: baseline; /* 2 */
}

/**
 * Prevent displaying `audio` without controls in Mobile Safari 4/5/6/7.
 */

audio:not([controls]) {
  display: none;
  height: 0;
}

/**
 * Address `[hidden]` styling not present in IE 8/9/10.
 * Hide the `template` element in IE 8/9/10/11,Safari,and Firefox < 22.
 */

[hidden],template {
  display: none;
}

/* Links
   ========================================================================== */

/**
 * Remove the gray background color from active links in IE 10.
 */

a {
  background-color: transparent;
}

/**
 * Improve readability of focused elements when they are also in an
 * active/hover state (opinionated).
 */

a:active,a:hover {
  outline-width: 0;
}

/* Text-level semantics
   ========================================================================== */

/**
 * Address inconsistent styling of `abbr[title]`.
 * 1. Correct styling in Firefox 39 and Opera 12.
 * 2. Correct missing styling in Chrome,Edge,IE,Opera,and Safari.
 */

abbr[title] {
  border-bottom: none; /* 1 */
  text-decoration: underline; /* 2 */
  text-decoration: underline dotted; /* 2 */
}

/**
 * Address inconsistent styling of b and strong.
 * 1. Correct duplicate application of `bolder` in Safari 6.0.2.
 * 2. Correct style set to `bold` in Edge 12+,Safari 6.2+,and Chrome 18+.
 */

b,strong {
  font-weight: inherit; /* 1 */
}

b,strong {
  font-weight: bolder; /* 2 */
}

/**
 * Address styling not present in Safari and Chrome.
 */

dfn {
  font-style: italic;
}

/**
 * Address variable `h1` font-size and margin within `section` and `article`
 * contexts in Firefox 4+,and Chrome.
 */

h1 {
  font-size: 2em;
  margin: 0.67em 0;
}

/**
 * Address styling not present in IE 8/9.
 */

mark {
  background-color: #ff0;
  color: #000;
}

/**
 * Address inconsistent and variable font size in all browsers.
 */

small {
  font-size: 80%;
}

/**
 * Prevent `sub` and `sup` affecting `line-height` in all browsers.
 */

sub,sup {
  font-size: 75%;
  line-height: 0;
  position: relative;
  vertical-align: baseline;
}

sup {
  top: -0.5em;
}

sub {
  bottom: -0.25em;
}

/* Embedded content
   ========================================================================== */

/**
 * Remove border when inside `a` element in IE 8/9/10.
 */

img {
  border: 0;
}

/**
 * Correct overflow not hidden in IE 9/10/11.
 */

svg:not(:root) {
  overflow: hidden;
}

/* Grouping content
   ========================================================================== */

/**
 * Address margin not present in IE 8/9 and Safari.
 */

figure {
  margin: 1em 40px;
}

/**
 * Address inconsistent styling of `hr`.
 * 1. Correct `Box-sizing` set to `border-Box` in Firefox.
 * 2. Correct `overflow` set to `hidden` in IE 8/9/10/11 and Edge 12.
 */

hr {
  Box-sizing: content-Box; /* 1 */
  height: 0; /* 1 */
  overflow: visible; /* 2 */
}

/**
 * Contain overflow in all browsers.
 */

pre {
  overflow: auto;
}

/**
 * 1. Correct inheritance and scaling of font-size for preformatted text.
 * 2. Address odd `em`-unit font size rendering in all browsers.
 */

code,kbd,pre,samp {
  font-family: monospace,monospace; /* 1 */
  font-size: 1em; /* 2 */
}

/* Forms
   ========================================================================== */

/**
 * Known limitation: by default,Chrome and Safari on OS X allow very limited
 * styling of `select`,unless a `border` property is set.
 */

/**
 * 1. Correct font properties not being inherited.
 * 2. Address margins set differently in Firefox 4+,and Chrome.
 */

button,input,optgroup,select,textarea {
  font: inherit; /* 1 */
  margin: 0; /* 2 */
}

/**
 * Address `overflow` set to `hidden` in IE 8/9/10/11.
 */

button {
  overflow: visible;
}

/**
 * Address inconsistent `text-transform` inheritance for `button` and `select`.
 * All other form control elements do not inherit `text-transform` values.
 * Correct `button` style inheritance in Firefox,IE 8/9/10/11,and Opera.
 * Correct `select` style inheritance in Firefox.
 */

button,select {
  text-transform: none;
}

/**
 * 1. Avoid the WebKit bug in Android 4.0.* where (2) destroys native `audio`
 *    and `video` controls.
 * 2. Correct inability to style clickable `input` types in iOS.
 * 3. Improve usability and consistency of cursor style between image-type
 *    `input` and others.
 */

button,html input[type="button"],/* 1 */
input[type="reset"],input[type="submit"] {
  -webkit-appearance: button; /* 2 */
  cursor: pointer; /* 3 */
}

/**
 * Re-set default cursor for disabled elements.
 */

button[disabled],html input[disabled] {
  cursor: default;
}

/**
 * Remove inner padding and border in Firefox 4+.
 */

button::-moz-focus-inner,input::-moz-focus-inner {
  border: 0;
  padding: 0;
}

/**
 * Restore focus style in Firefox 4+ (unset by a rule above)
 */

button:-moz-focusring,input:-moz-focusring {
  outline: 1px dotted ButtonText;
}

/**
 * Address Firefox 4+ setting `line-height` on `input` using `!important` in
 * the UA stylesheet.
 */

input {
  line-height: normal;
}

/**
 * It's recommended that you don't attempt to style these elements.
 * Firefox's implementation doesn't respect Box-sizing,padding,or width.
 *
 * 1. Address Box sizing set to `content-Box` in IE 8/9/10.
 * 2. Remove excess padding in IE 8/9/10.
 */

input[type="checkBox"],input[type="radio"] {
  Box-sizing: border-Box; /* 1 */
  padding: 0; /* 2 */
}

/**
 * Fix the cursor style for Chrome's increment/decrement buttons. For certain
 * `font-size` values of the `input`,it causes the cursor style of the
 * decrement button to change from `default` to `text`.
 */

input[type="number"]::-webkit-inner-spin-button,input[type="number"]::-webkit-outer-spin-button {
  height: auto;
}

/**
 * Address `appearance` set to `searchfield` in Safari and Chrome.
 */

input[type="search"] {
  -webkit-appearance: textfield;
}

/**
 * Remove inner padding and search cancel button in Safari and Chrome on OS X.
 * Safari (but not Chrome) clips the cancel button when the search input has
 * padding (and `textfield` appearance).
 */

input[type="search"]::-webkit-search-cancel-button,input[type="search"]::-webkit-search-decoration {
  -webkit-appearance: none;
}

/**
 * Define consistent border,margin,and padding.
 */

fieldset {
  border: 1px solid #c0c0c0;
  margin: 0 2px;
  padding: 0.35em 0.625em 0.75em;
}

/**
 * 1. Correct `color` not being inherited from fieldset in IE 8/9/10/11.
 * 2. Remove padding so people aren't caught out if they zero out fieldsets.
 */

legend {
  color: inherit; /* 1 */
  padding: 0; /* 2 */
}

/**
 * Remove default vertical scrollbar in IE 8/9/10/11.
 */

textarea {
  overflow: auto;
}

/**
 * Restore font weight (unset by a rule above).
 * NOTE: the default cannot safely be changed in Chrome and Safari on OS X.
 */

optgroup {
  font-weight: bold;
}

<h2 class="titoloPagina">
  <span>Title</span>
</h2>

使用Mozilla Firefox时,第一个字母与下划线基本对齐,而使用Internet Explorer 11则低15px.

我错过了什么？