* {
    box-sizing: border-box;
}

html,
body {
    margin: 0;
    padding: 0;
}

body {
	font-family: var(--font-body);
	text-align: center;
}

/*============================ PAGE TRANSITIONS ============================*/

@view-transition {
    navigation: auto;
}

::view-transition-old(root) {
    animation-duration: 0.3s;
}

::view-transition-new(root) {
    animation-duration: 0.3s;
}

:root {
    --font-heading: "Orbitron", sans-serif;
    --font-body: Arial, Helvetica, sans-serif;

/*============================ COLORS ============================*/

--color-teal: #00a79d;
--color-blue: #1c75bc;
--color-dark-green: #009444;
--color-light-green: #8dc63f;
--color-black: #000000;
--color-dark-charcoal: #001c1b;
--color-charcoal: #232323;
--color-dark-grey: #6d6e71;
--color-medium-grey: #939598;
--color-light-grey: #dcddde;
--color-white: #FFFFFF;

--color-red: #ff0013;

}

p {
    margin: 0 0 15px;
    line-height: 1.5;
}

p:last-child {
    margin-bottom: 0;
}

hr {
    border: 0;
    margin: 50px 0;
    border-top: 1px solid var(--color-light-grey);
}

h1 {
    font-family: var(--font-heading);
    font-size: 40px; 
    color: var(--color-teal);
    margin: 16px 0;
}

h2 {
    font-family: var(--font-heading);
    font-size: 26px; 
    color: var(--color-black);
    margin: 14px 0;
}

h3 {
    font-family: var(--font-heading);
    font-size: 20px; 
    color: var(--color-charcoal);
    margin: 12px 0;
}

h4 {
    font-family: var(--font-heading);
    font-size: 12px; 
    color: var(--color-medium-grey);
    margin: 12px 0;
}

.main-nav__menu a {
    font-family: var(--font-heading);
}

/*============================ LINKS ============================*/

.bwm-text-link {
    color: var(--color-teal);
    font-weight: 700;
    text-decoration: none;
    transition: color 0.2s ease;
    text-decoration: underline;
}

.bwm-text-link:hover {
    color: var(--color-black);
}

.bwm-text-link:focus-visible {
    outline: 2px solid var(--color-teal);
    outline-offset: 3px;
    border-radius: 2px;
}

/*============================ BUTTONS ============================*/

.btn {
    display: inline-flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    padding: 12px 22px;

    font-family: var(--font-heading);
    font-size: 16px;
    font-weight: 500;
    letter-spacing: 0.03em;

    text-decoration: none;
    border: 2px solid transparent;
    border-radius: 5px;

    cursor: pointer;
    transition: all 0.2s ease;
}

/* Primary */

.btn--primary {
    color: var(--color-black);
    background-color: var(--color-teal);
    border-color: var(--color-teal);
}

.btn--primary:hover {
    color: var(--color-teal);
    background-color: var(--color-charcoal);
    border-color: var(--color-teal);
}

/* Secondary */

.btn--secondary {
    color: var(--color-teal);
    background-color: transparent;
    border-color: var(--color-teal);
}

.btn--secondary:hover {
    color: var(--color-white)fff;
    background-color: var(--color-teal);
}

/* Keyboard accessibility */

.btn:focus-visible {
    outline: 3px solid var(--color-teal);
    outline-offset: 3px;
}

.btn--large {
    padding: 22px 36px;
    font-size: 26px;
    gap: 12px;
}

/*============================ SECTION HEADERS ============================*/

.portfolio__section-header--outer {
    background-color: var(--color-charcoal);
    padding: 50px 25px;
    text-align: center;
}

.portfolio__section-header--inner {
    max-width: 992px;
    margin: 0 auto;
}

.portfolio__section-header--outer___about-page {
    background-color: var(--color-charcoal);
    padding: 50px 25px;
    text-align: center;
}

.portfolio__section-header--outer h1 {
    margin: 0 0 16px;
}

.portfolio__section-header__text {
    color: var(--color-white);
}

@media (min-width: 768px) {

.portfolio__section-header--outer {
    padding: 121px 0;
    text-align: left;
}

.portfolio__section-header--about-page {
    padding: 75px 0;
}

.portfolio__section-header--outer___about-page {
    padding: 75px 0;
    text-align: left;
}

}

/*============================ BACK TO TOP ============================*/

.back-to-top {
    position: fixed;
    right: 25px;
    bottom: 25px;
    z-index: 1000;

    display: flex;
    justify-content: center;
    align-items: center;

    width: 50px;
    height: 50px;
    padding: 0;

    font-size: 20px;
    color: var(--color-white);

    background-color: rgba(0, 0, 0, 0.75);
    border: 1px solid var(--color-medium-grey);
    border-radius: 50%;

    cursor: pointer;

    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);

    transition:
        opacity 0.3s ease,
        visibility 0.3s ease,
        transform 0.3s ease,
        background-color 0.3s ease,
        border-color 0.3s ease;
}

.back-to-top.is-visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:active {
    transform: scale(0.95);
}

.back-to-top:focus-visible {
    outline: 2px solid var(--color-teal);
    outline-offset: 3px;
}

@media (hover: hover) {

    .back-to-top:hover {
        background-color: var(--color-teal);
        border-color: var(--color-teal);
    }

}

/*============================ MOBILE CONTACT BUTTON ============================*/

.contact-button {
    position: fixed;
    left: 25px;
    bottom: 25px;
    z-index: 1000;

    display: flex;
    justify-content: center;
    align-items: center;

    width: 50px;
    height: 50px;

    font-size: 20px;
    color: var(--color-white);
    text-decoration: none;

    background-color: rgba(0, 0, 0, 0.75);
    border: 1px solid var(--color-medium-grey);
    border-radius: 50%;

    -webkit-tap-highlight-color: rgba(0, 167, 157, 0.20);

    transition:
        transform 0.15s ease,
        background-color 0.2s ease,
        border-color 0.2s ease;
}

.contact-button:active {
    transform: scale(0.95);
    background-color: var(--color-teal);
    border-color: var(--color-teal);
}

.contact-button:focus-visible {
    outline: 2px solid var(--color-teal);
    outline-offset: 3px;
}