:root {
    /* == Spacing == */
    --max-width: 1200px; /* A size that allows the page content to be readable and centered even on wider screens */
    --horizontally-centered-margins: 0 auto; /* Centers the container horizontally */
    --padding-edges: 0 20px; /* Keeps the content from touching the browser edges on small screens */

    /* == Variables related to header size and used to compute menu top position on mobile == */
    --header-height: 60px; /* Header height */
    --header-border-size: 2px; /* Header border size */

    /* == Variables related to navbar == */
    --logo-height: 40px; /* Logo height size */
    --navbar-vertical-padding: 8px; /* Navbar vertical padding */
    --menu-voices-gap: 32px; /* Gap between menu voices */
    --menu-offset: 8px; /* Slight offset to distance all voices from controllers */

    /* == Colors == */
    --body-background-color: rgb(255, 255, 255); /* Body background */
    --menu-background-color: rgb(165, 219, 165); /* Menu background */
    --menu-background-mobile-color: rgb(255, 255, 255); /* Menu background on mobile */
    --section-odd-background-color: rgb(255, 255, 255); /* Section odd background color */
    --section-even-background-color: rgb(239, 243, 239); /* Section even background color */
    --card-odd-background-color: rgb(249, 249, 249); /* Card odd background color */
    --card-even-background-color: rgb(255, 255, 255); /* Card even background color */
    --footer-background-color: rgb(16, 32, 56); /* Footer background color */

    --body-text-color: rgb(85, 85, 85); /* Body text color */
    --menu-text-color: rgb(30, 41, 57); /* Menu text color */
    --card-text-color: rgb(85, 85, 85); /* Card text color */
    --motto-text-color: rgb(241, 139, 106); /* Motto text color */
    --footer-text-color: rgb(204, 210, 213); /* Footer text color */

    --header-border-color: rgb(229, 229, 229); /* Header border */
    --grid-border-even-color: rgb(227, 223, 231); /* Grid border color on even sections */

    --card-shadow: rgba(20, 20, 20, 0.2); /* Card shadow */
    --image-shadow: rgb(107, 114, 128, 0.6); /* About image shadow */
    --envelope-svg-color: rgb(16, 40, 56); /* Envelope svg color */
}

/* Reset rules applied to all page elements */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--body-background-color);
    font-family: system-ui, -apple-system, sans-serif;
    line-height: 1.6;
    color: var(--body-text-color);
}

section {
    padding: 80px 0;
}

/* Spacing classes */
.text-centered {
    text-align: center;
}

.container {
    max-width: var(--max-width);
    margin: var(--horizontally-centered-margins);
    padding: var(--padding-edges);
}

.hero {
    padding: 120px 0 40px;
    background: var(--section-odd-background-color);
    color: var(--menu-text-color);
}

.hero p {
    margin-bottom: 1.8rem;
    font-size: 1.5rem;
    opacity: 0.8;
}

.hero-title {
    margin-bottom: 1.5rem;
    font-size: 3rem;
    font-weight: bold;
    line-height: 1.3;
}

.hero-highlight {
    color: var(--menu-background-color);
}

.section-title {
    margin-bottom: 1.5rem;
    text-align: center;
    font-size: 2.5rem;
    font-weight: bold;
    color: var(--menu-text-color);
}

/* Header */
.header {
    position: fixed;
    top: 0;
    width: 100%;
    height: var(--header-height);
    border-bottom: var(--header-border-size) solid var(--header-border-color);
    background: var(--menu-background-color);
    z-index: 1000;
}

.navbar {
    padding: var(--navbar-vertical-padding) 0;
}

.nav-container {
    display: flex;
    /* The horizontal distribution of the flex items.
       i.e. |Item1       Item2       Item3|
    */
    justify-content: space-between;
    align-items: center;
    padding: var(--padding-edges);
}

.nav-left .logo {
    max-width: 100%;
    width: auto;
    height: var(--logo-height);
    /* Force the logo to align at the top of its parent container <a> */
    vertical-align: top;
    transition: opacity .3s ease;
}

.nav-left .logo:hover {
    opacity: 0.7;
    cursor: pointer;
}

.nav-menu {
    display: flex;
    justify-content: flex-end;
    align-items: center;
}

.nav-voices {
    display: flex;
    gap: var(--menu-voices-gap);
    list-style: none;
    margin-right: calc(var(--menu-voices-gap) + var(--menu-offset));
}

.nav-link {
    display: block;
    font-size: 1.1rem;
    font-weight: bold;
    text-decoration: none;
    color: var(--menu-text-color);
    transition: transform .2s ease;
}

.nav-link:hover {
    transform: scale(1.1);
}

.nav-link-selected {
    color: var(--menu-background-mobile-color);
    filter: contrast(1.5);
    transform: none !important;
}

.nav-controllers {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: calc(var(--menu-voices-gap) / 2);
}

.github-mark {
    display: flex;
    /* Setting 50% border-radius makes the element a perfect circle
       since its width and height are equal
    */
    border-radius: 50%;
    color: var(--menu-text-color);
    transition: transform .2s ease;
}

.github-mark:hover {
    transform: scale(1.2);
}

.multilang-link {
    font-size: 1.1rem;
    font-weight: bold;
    text-decoration: none;
    text-transform: uppercase;
    color: var(--menu-text-color);
    transition: transform .2s ease;
}

.multilang-link:hover {
    transform: scale(1.2);
}

.burger-menu {
    display: none;
}

/* Button */
.button-container {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    /* Do not allow buttons to wrap to the next line on smaller screens */
    flex-wrap: no-wrap;
}

.button-same-width {
    width: 200px;
}

.button {
    display: inline-block;
    padding: 8px 16px;
    border-radius: 50px;
    border: 1px solid transparent;
    font-weight: bold;
    font-size: 1.1rem;
    text-decoration: none;
    transition: opacity .2s ease;
}

.button-primary {
    background-color: var(--menu-background-color);
    color: var(--menu-text-color);
}

.button-primary:hover {
    opacity: 0.8;
}

/* Cards */
.cards {
    background-color: var(--section-even-background-color);
}

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.card-odd-color {
    background-color: var(--card-odd-background-color);
    border: 2px solid var(--grid-border-even-color);
    transition: all .1s ease;
}

.card-odd-color:hover {
    box-shadow: 0 20px 20px rgba(10, 10, 10, 0.2);
}

.card-even-color {
    background-color: var(--card-even-background-color);
    border: 1px solid var(--grid-border-even-color);
    transition: all .2s ease;
}

.card-even-color:hover {
    box-shadow: 0 20px 20px var(--card-shadow);
}

.card {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 2.5rem 2rem;
    border-radius: 30px;
}

.card h3 {
    width: 100%;
    margin-bottom: 1rem;
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--menu-text-color);
}

.card p {
    width: 100%;
    margin-bottom: 0.8rem;
    font-size: 1.1rem;
    line-height: 1.7;
    word-break: keep-all;
}

.card a {
    text-decoration: none;
    color: var(--menu-background-color);
    filter: brightness(0.95);
    font-weight: 600;
}

.card a:hover {
    filter: brightness(1);
}

.card-icon {
    width: 100%;
    height: 3rem;
    margin-bottom: 1rem;
    /* A workaround to make the leaf appear horizontally centered */
    padding-left: 1rem;
    color: var(--menu-background-color);
}

.info-card {
    padding: 2.5rem 1.5rem;
    border-radius: 30px;
}

.info-card h3 {
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--menu-text-color);
}

.info-card p {
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
    line-height: 1.6;
    word-break: keep-all;
}

.info-card a {
    text-decoration: none;
    color: var(--menu-background-color);
    filter: brightness(0.95);
    font-weight: 500;
}

.info-card a:hover {
    filter: brightness(1);
}

/* Contacts */
.contacts {
    background-color: var(--section-odd-background-color);
}

.contacts-info {
    margin: var(--horizontally-centered-margins) 30px;
    text-align: center;
}

.email-svg {
    display: block;
    width: 100%;
    height: 3.4rem;
    margin: var(--horizontally-centered-margins) 12px;
    color: var(--envelope-svg-color);
}

.email-text {
   margin: var(--horizontally-centered-margins) 30px;
   font-weight: bold;
   color: var(--menu-text-color);
}

/* About page */
.about-toscalabs {
    background-color: var(--section-even-background-color);
}

.about-toscalabs-name {
    background-color: var(--section-odd-background-color);
}

.about-toscalabs-panels {
    display: flex;
    flex-wrap: nowrap;
    align-items: center;
    justify-content: center;
    width: 100%;
    margin-top: 4rem;
}

.about-toscalabs-panels p {
    line-height: 1.75rem;
}

.toscalabs-panel {
    width: 50vw;
    margin: auto 2rem;
}

.toscalabs-panel p {
    font-size: 1.2rem;
    margin-bottom: 1.8rem;
}

.motto-panel {
    width: 50vw;
    margin: 4rem auto auto;
}

.motto {
    font-family: "Inter", system-ui, -apple-system, sans-serif;
    letter-spacing: 0.02em;
    font-size: calc(1.3rem + 0.5vw);
    font-weight: bold;
    font-style: italic;
    line-height: 1.4;
    text-align: center;
    color: var(--motto-text-color);
    opacity: 0.8;
}

.image-panel {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 50%;
    margin: auto 2rem;
}

.image-panel img {
    width: 420px;
    height: 420px;
    box-shadow: 0 10px 15px -3px var(--image-shadow), 0 4px 6px -4px var(--image-shadow);
}

.name-panel {
    width: 50%;
    margin: auto 2rem;
}

.name-panel p {
    width: 100%;
    margin-bottom: 1.4rem;
}

.about-method {
    background-color: var(--section-odd-background-color);
}

.about-cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

/* Tosca Page */
.tosca-demo {
    background-color: var(--section-even-background-color);
}

.video-container {
    position: relative;
    width: 100%;
    height: 0;
    margin-bottom: 1rem;
    /* 16:9 aspect ratio */
    padding-bottom: 56.25%;
    overflow: hidden;
}

.video {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.demo-description {
    margin-bottom: 1.8rem;
    font-size: 1.4rem;
    opacity: 0.8;
}

.tosca-features {
    background-color: var(--section-even-background-color);
}

.tosca-cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.tosca-contacts {
    background-color: var(--section-odd-background-color);
}

.contacts-subtitle {
    margin-bottom: 1.8rem;
    font-size: 1.4rem;
    opacity: 0.7;
}

/* Footer */
.footer {
    padding: 3rem 0 1rem;
    background-color: var(--footer-background-color);
}

.footer-info {
    display: flex;
    justify-content: center;
    padding-top: 1rem;
    font-weight: 500;
    color: var(--footer-text-color);
}

/* Large desktop screens */
@media screen and (min-width: 2000px) {
    .motto {
        font-size: 1.8rem;
    }
}


/* Large tablets in landscape mode */
@media screen and (max-width: 1024px) {
    .about-toscalabs-panels {
        flex-direction: column;
        align-items: center;
        justify-content: center;
    }

    .motto-panel {
        margin-top: 2rem;
        width: 100%;
    }

    .motto {
        font-size: calc(1.5rem + 0.5vw);
    }
}

/* Small tablets in portrait mode */
@media screen and (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: calc(var(--header-height) + var(--header-border-size));
        left: -100%;
        right: 0;
        height: 100vh;
        flex-direction: column;
        justify-content: center;
        gap: var(--menu-voices-gap);
        background-color: var(--menu-background-mobile-color);
        /* A filter to hide the content behind */
        backdrop-filter: blur(20px);
        /* Safari version of the filter */
        -webkit-backdrop-filter: blur(20px);
        text-align: center;
        visibility: hidden;
        opacity: 0;
        z-index: 1000;
        transition: left 0.25s ease, opacity 0.25s ease;
    }

    body.active {
        overflow: hidden;
    }

    .nav-menu.active {
        left: 0;
        visibility: visible;
        opacity: 1;
    }

    .nav-voices {
        width: 100%;
        margin-right: 0;
        flex-direction: column;
    }

    .nav-controllers {
        width: 100%;
        justify-content: center;
        padding-right: calc(var(--menu-voices-gap) / 8);
    }

    .nav-link,
    .multilang-link,
    .github-mark {
        transition: none !important;
    }

    .nav-link:hover,
    .multilang-link:hover,
    .github-mark:hover {
        transform: none !important;
    }

    .nav-link-selected {
        color: var(--menu-background-color);
        filter: contrast(0.9);
    }

    .burger-menu {
        position: relative;
        display: flex;
        flex-direction: column;
        justify-content: space-around;
        width: 30px;
        height: 23px;
        background: transparent;
        cursor: pointer;
        z-index: 1000;
    }

    .burger-menu .bar {
        position: absolute;
        width: 30px;
        height: 3px;
        background-color: var(--menu-text-color);
    }

    .burger-menu .bar-1 {
        top: 0;
    }

    .burger-menu .bar-2 {
        top: 50%;
        transform: translateY(-50%);
    }

    .burger-menu .bar-3 {
        bottom: 0;
    }

    .burger-menu.active .bar-1 {
        transform: rotate(45deg);
        top: 50%;
        transform: translateY(-50%) rotate(45deg);
    }

    .burger-menu.active .bar-2 {
        opacity: 0;
    }

    .burger-menu.active .bar-3 {
        transform: rotate(-45deg);
        bottom: 50%;
        transform: translateY(50%) rotate(-45deg);
    }

    .container {
        padding: 0 15px;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .section-title {
        font-size: 2.2rem;
    }

    .motto-panel {
        margin-top: 1rem;
        width: 100%;
    }

    .motto {
        font-size: calc(1.4rem + 0.5vw);
    }

    .button-container {
        padding: 0 3rem;
    }

    .button {
        width: 250px;
    }

    .about-toscalabs-panels {
        flex-direction: column;
        align-items: center;
        justify-content: center;
    }

    .about-toscalabs-panels p {
        font-size: 1.2rem;
    }

    .toscalabs-panel {
        padding-bottom: 1.5rem;
        width: 100%;
    }

    .image-panel {
        width: 100%;
        margin: 0 0 1.5rem;
    }

    .name-panel {
        width: 100%;
    }

    .cards-grid,
    .about-cards-grid,
    .tosca-cards-grid {
        grid-template-columns: 1fr;
    }

    .demo-description {
        padding: 0 1rem;
        font-size: 1.3rem;
    }
}

/* Only mobile */
@media screen and (max-width: 480px) {
    .hero-title,
    .section-title {
        font-size: 2rem;
    }

    .motto {
        font-size: calc(1.4rem + 0.5vw);
    }
}