:root {
    color-scheme: light;
    --color-ink: #18243a;
    --color-muted: #53627a;
    --color-primary: #2448c7;
    --color-primary-dark: #172f86;
    --color-primary-light: #eaf0ff;
    --color-border: #dce3ef;
    --color-surface: #ffffff;
    --color-page: #f3f6fb;
    --shadow-card: 0 18px 50px rgb(23 47 134 / 9%);
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 1.5rem;
}

body {
    margin: 0;
    background: var(--color-page);
    color: var(--color-ink);
    font-family: Arial, Helvetica, sans-serif;
    line-height: 1.7;
}

a {
    color: var(--color-primary);
}

a:focus-visible {
    outline: 3px solid #f4b740;
    outline-offset: 4px;
}

.skip-link {
    position: absolute;
    z-index: 2;
    top: 1rem;
    left: 1rem;
    padding: 0.65rem 1rem;
    transform: translateY(-160%);
    border-radius: 0.5rem;
    background: var(--color-surface);
    color: var(--color-primary-dark);
    font-weight: 700;
}

.skip-link:focus {
    transform: translateY(0);
}

header {
    padding: 2rem max(1.5rem, calc((100% - 1200px) / 2));
    background: linear-gradient(125deg, #172f86, #315bdd);
    color: white;
}

.entete {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
}

.identite {
    display: inline-flex;
    flex-shrink: 0;
    align-items: center;
    gap: 0.7rem;
    color: white;
    text-decoration: none;
}

.identite-marque {
    display: grid;
    width: 2.75rem;
    height: 2.75rem;
    place-items: center;
    border: 1px solid rgb(255 255 255 / 28%);
    border-radius: 0.8rem;
    background: rgb(255 255 255 / 12%);
    font-family: "Courier New", Courier, monospace;
    font-size: 1rem;
    font-weight: 700;
}

.identite strong,
.identite-sous-titre {
    display: block;
}

.identite strong {
    line-height: 1.3;
}

.identite-sous-titre {
    margin-top: 0.15rem;
    color: #d8e2ff;
    font-size: 0.82rem;
}

header h1 {
    margin: 0;
    color: white;
    font-size: clamp(1.8rem, 4vw, 2.5rem);
    line-height: 1.2;
}

header p {
    margin: 0.5rem 0 0;
    color: #e0e8ff;
}

nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 0.4rem;
}

nav a {
    padding: 0.55rem 0.8rem;
    border: 1px solid transparent;
    border-radius: 0.55rem;
    color: white;
    font-size: 0.95rem;
    font-weight: 700;
    text-decoration: none;
    transition: background-color 160ms ease, border-color 160ms ease;
}

nav a:hover {
    border-color: rgb(255 255 255 / 35%);
    background: rgb(255 255 255 / 14%);
}

nav a[aria-current="page"] {
    border-color: rgb(255 255 255 / 35%);
    background: rgb(255 255 255 / 16%);
}

main {
    width: min(92%, 1120px);
    margin: 2.5rem auto;
    overflow: hidden;
    border: 1px solid var(--color-border);
    border-radius: 1.25rem;
    background: var(--color-surface);
    box-shadow: var(--shadow-card);
}

section {
    padding: clamp(1.5rem, 5vw, 3.5rem);
    border-bottom: 1px solid var(--color-border);
    scroll-margin-top: 1rem;
}

section:last-child {
    border-bottom: 0;
}

section.introduction {
    background:
        radial-gradient(ellipse at top right, rgb(75 112 231 / 12%), transparent 55%),
        #f8faff;
}

.introduction h1 {
    margin: 0 0 1rem;
    color: var(--color-primary-dark);
    font-size: clamp(2rem, 4vw, 2.7rem);
    line-height: 1.2;
}

.introduction > p {
    max-width: 68ch;
}

.introduction .badge {
    margin-bottom: 1rem;
}

.accueil-hero {
    position: relative;
    display: grid;
    min-height: 450px;
    grid-template-columns: 1.1fr 0.9fr;
    align-items: center;
    gap: 2rem;
    overflow: hidden;
    padding: clamp(2rem, 6vw, 5rem);
    background:
        radial-gradient(ellipse at 78% 44%, rgb(96 131 238 / 22%), transparent 42%),
        linear-gradient(135deg, #f9fbff, #edf2ff);
}

.hero-texte {
    position: relative;
    z-index: 1;
}

.hero-texte h1 {
    max-width: 12ch;
    margin: 0.8rem 0 1rem;
    color: var(--color-primary-dark);
    font-size: clamp(2.5rem, 5vw, 4.2rem);
    letter-spacing: -0.045em;
    line-height: 1.05;
}

.hero-description {
    max-width: 50ch;
    color: var(--color-muted);
    font-size: 1.12rem;
}

.hero-texte .actions {
    margin-bottom: 1rem;
}

.hero-signature {
    margin: 0;
    color: var(--color-muted);
    font-size: 0.9rem;
}

.hero-visuel {
    position: relative;
    display: grid;
    min-height: 270px;
    place-items: center;
}

.fenetre-code {
    width: min(100%, 440px);
    overflow: hidden;
    border: 1px solid #33425f;
    border-radius: 1rem;
    background: #172033;
    box-shadow: 0 24px 55px rgb(23 32 51 / 22%);
    transform: rotate(2deg);
}

.fenetre-points {
    display: flex;
    gap: 0.4rem;
    padding: 1rem 1.2rem 0;
}

.fenetre-points span {
    width: 0.6rem;
    height: 0.6rem;
    border-radius: 50%;
    background: #ff7777;
}

.fenetre-points span:nth-child(2) {
    background: #ffc857;
}

.fenetre-points span:nth-child(3) {
    background: #57d6a0;
}

.fenetre-code pre {
    margin: 0;
    overflow-x: auto;
    border: 0;
    border-radius: 0;
    background: transparent;
    padding: 1rem 1.3rem 1.5rem;
    font-size: clamp(0.7rem, 1.3vw, 0.9rem);
    line-height: 1.8;
}

.code-comment {
    color: #9aa8c5;
}

.code-balise {
    color: #83a3ff;
}

.code-selecteur {
    color: #ffd580;
}

.code-propriete {
    color: #82dfc2;
}

.code-valeur {
    color: #ff9cbd;
}

.hero-etiquette {
    position: absolute;
    padding: 0.55rem 0.85rem;
    border: 1px solid var(--color-border);
    border-radius: 999px;
    background: white;
    box-shadow: 0 8px 20px rgb(23 47 134 / 10%);
    color: var(--color-primary-dark);
    font-size: 0.85rem;
    font-weight: 700;
}

.hero-etiquette-html {
    top: 1rem;
    left: 0;
}

.hero-etiquette-css {
    right: 0;
    bottom: 1rem;
}

.sur-titre {
    display: inline-block;
    margin-bottom: 0.55rem;
    color: var(--color-primary);
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

main > section:not(.accueil-hero) > h2 {
    max-width: 30ch;
}

.texte-intro {
    max-width: 70ch;
    color: var(--color-muted);
    font-size: 1.05rem;
}

.projet-points {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1rem;
    margin-top: 2rem;
}

.point-projet {
    padding: 1.4rem;
    border: 1px solid var(--color-border);
    border-radius: 0.85rem;
    background: #f8faff;
}

.point-icone {
    display: grid;
    width: 2.7rem;
    height: 2.7rem;
    place-items: center;
    margin-bottom: 1rem;
    border-radius: 0.7rem;
    background: var(--color-primary-light);
    color: var(--color-primary-dark);
    font-family: "Courier New", Courier, monospace;
    font-weight: 700;
}

.point-projet h3 {
    margin: 0 0 0.4rem;
    color: var(--color-ink);
    font-size: 1.1rem;
}

.point-projet p {
    margin: 0;
    color: var(--color-muted);
    font-size: 0.95rem;
}

.section-parcours {
    background: #f8faff;
}

.cartes-cours {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1rem;
    margin-top: 2rem;
}

.carte-cours {
    display: flex;
    min-height: 240px;
    flex-direction: column;
    align-items: flex-start;
    padding: 1.35rem;
    border: 1px solid var(--color-border);
    border-radius: 0.9rem;
    background: white;
    color: var(--color-ink);
    text-decoration: none;
    transition: border-color 160ms ease, box-shadow 160ms ease, transform 160ms ease;
}

.carte-cours:hover {
    transform: translateY(-4px);
    border-color: #a8b9ed;
    box-shadow: 0 12px 28px rgb(23 47 134 / 9%);
}

.carte-numero {
    color: var(--color-muted);
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.08em;
}

.carte-icone {
    display: grid;
    width: 2.6rem;
    height: 2.6rem;
    place-items: center;
    margin: 1.1rem 0 0.7rem;
    border-radius: 0.7rem;
    background: var(--color-primary-light);
    color: var(--color-primary-dark);
    font-size: 1.1rem;
    font-weight: 700;
}

.carte-cours > strong {
    margin-bottom: 0.35rem;
    color: var(--color-primary-dark);
    font-size: 1.08rem;
}

.carte-cours > span:nth-last-child(2) {
    color: var(--color-muted);
    font-size: 0.9rem;
    line-height: 1.5;
}

.carte-lien {
    display: flex;
    width: 100%;
    justify-content: space-between;
    gap: 0.5rem;
    margin-top: auto;
    padding-top: 1rem;
    color: var(--color-primary);
    font-size: 0.88rem;
    font-weight: 700;
}

.carte-cours-final {
    border-color: #c4d1fb;
    background: linear-gradient(145deg, #f3f6ff, #ffffff);
}

.appel-projet {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
    background: var(--color-primary-dark);
    color: white;
}

.appel-projet .sur-titre {
    color: #b9caff;
}

.appel-projet h2 {
    margin-bottom: 0.5rem;
    border: 0;
    color: white;
}

.appel-projet p {
    margin: 0;
    color: #e0e8ff;
}

.appel-projet .bouton {
    flex-shrink: 0;
    border-color: white;
    background: white;
    color: var(--color-primary-dark);
}

.appel-projet .bouton:hover {
    background: #eaf0ff;
}

h2 {
    margin: 0 0 1.5rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--color-border);
    color: var(--color-primary-dark);
    font-size: clamp(1.65rem, 3vw, 2rem);
    line-height: 1.3;
}

h3 {
    margin: 2rem 0 0.75rem;
    color: var(--color-primary);
    font-size: 1.25rem;
    line-height: 1.4;
}

p {
    margin: 0 0 1rem;
}

section > p {
    max-width: 72ch;
}

img {
    display: block;
    width: min(100%, 480px);
    max-height: 300px;
    margin: 1.5rem auto;
    border: 1px solid var(--color-border);
    border-radius: 0.9rem;
    object-fit: cover;
    box-shadow: 0 8px 24px rgb(24 36 58 / 10%);
}

ul,
ol {
    padding-left: 1.5rem;
    line-height: 1.8;
}

li::marker {
    color: var(--color-primary);
}

pre {
    max-width: 100%;
    margin: 1.25rem 0;
    overflow-x: auto;
    border: 1px solid #303f5d;
    border-left: 4px solid #7191ff;
    border-radius: 0.75rem;
    background: #172033;
    color: #eef3ff;
    padding: 1.25rem;
    tab-size: 4;
}

code {
    font-family: "Courier New", Courier, monospace;
    font-size: 0.92em;
}

.important {
    margin: 1.5rem 0;
    padding: 1.25rem 1.5rem;
    border: 1px solid #cbd7ff;
    border-left: 5px solid var(--color-primary);
    border-radius: 0.75rem;
    background: var(--color-primary-light);
}

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

.actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin: 1.5rem 0 2rem;
}

.bouton {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 2.8rem;
    padding: 0.65rem 1.1rem;
    border: 1px solid var(--color-primary-dark);
    border-radius: 0.6rem;
    background: var(--color-primary-dark);
    color: white;
    font-weight: 700;
    text-decoration: none;
    transition: background-color 160ms ease, transform 160ms ease;
}

.bouton:hover {
    transform: translateY(-2px);
    background: var(--color-primary);
}

.bouton-secondaire {
    background: transparent;
    color: var(--color-primary-dark);
}

.bouton-secondaire:hover {
    background: var(--color-primary-light);
    color: var(--color-primary-dark);
}

.parcours {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1rem;
    margin: 1rem 0 1.5rem;
}

.etape {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.35rem;
    min-height: 9rem;
    padding: 1rem;
    border: 1px solid var(--color-border);
    border-radius: 0.75rem;
    background: var(--color-surface);
    color: var(--color-ink);
    text-decoration: none;
    transition: border-color 160ms ease, box-shadow 160ms ease, transform 160ms ease;
}

.etape:hover {
    transform: translateY(-3px);
    border-color: #9aafea;
    box-shadow: 0 8px 20px rgb(23 47 134 / 8%);
}

.numero-etape {
    color: var(--color-primary);
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 0.08em;
}

.etape strong {
    color: var(--color-primary-dark);
}

.etape > span:last-child {
    color: var(--color-muted);
    font-size: 0.95rem;
    line-height: 1.5;
}

.proprietes {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 1rem;
}

.proprietes div {
    padding: 1.15rem;
    border: 1px solid var(--color-border);
    border-radius: 0.75rem;
    background: #f8faff;
    text-align: center;
}

.proprietes strong {
    color: var(--color-primary-dark);
}

.proprietes p {
    margin: 0.35rem 0 0;
    color: var(--color-muted);
}

.demo-flex {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1rem;
    margin: 1.25rem 0;
    padding: 1.25rem;
    border: 1px dashed #aebde8;
    border-radius: 0.85rem;
    background: #f8faff;
}

.demo-flex div,
.demo-grid div {
    border-radius: 0.65rem;
    background: var(--color-primary-dark);
    color: white;
    font-weight: 700;
}

.demo-flex div {
    padding: 1rem 1.25rem;
}

.demo-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1rem;
    margin: 1.25rem 0;
    padding: 1.25rem;
    border: 1px dashed #aebde8;
    border-radius: 0.85rem;
    background: #f8faff;
}

.demo-grid div {
    padding: 1.25rem;
    text-align: center;
    font-size: 1.2rem;
}

.demo-animation {
    width: fit-content;
    margin: 2rem auto;
    padding: 1rem 1.4rem;
    border-radius: 0.75rem;
    background: var(--color-primary-dark);
    color: white;
    font-weight: 700;
    animation: mouvement 3s ease-in-out infinite;
}

@keyframes mouvement {
    0%,
    100% {
        transform: translateX(-60px);
    }

    50% {
        transform: translateX(60px);
    }
}

.exercice {
    margin: 1.25rem 0;
    padding: 1.25rem 1.5rem;
    border: 1px solid var(--color-border);
    border-radius: 0.85rem;
    background: #f8faff;
}

.exercice h3 {
    margin-top: 0;
}

.exercice-final {
    border-color: #c4d1fb;
    background: linear-gradient(135deg, #f3f6ff, #fbfcff);
}

.badge {
    display: inline-block;
    width: fit-content;
    margin-bottom: 0.75rem;
    padding: 0.25rem 0.65rem;
    border-radius: 999px;
    background: var(--color-primary-light);
    color: var(--color-primary-dark);
    font-size: 0.8rem;
    font-weight: 700;
}

.navigation-lecon {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}

.lien-retour {
    color: var(--color-primary-dark);
    font-weight: 700;
    text-decoration: none;
}

.lien-retour:hover {
    text-decoration: underline;
}

.exercice p:last-child,
.exercice ul:last-child {
    margin-bottom: 0;
}

footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1.5rem;
    padding: 2rem 1.5rem;
    background: #172033;
    color: white;
    text-align: left;
}

footer p {
    margin: 0;
}

.footer-link {
    color: #b9caff;
    font-weight: 700;
}

.footer-link:hover {
    color: white;
}

.identite-footer {
    color: white;
}

.identite-footer .identite-marque {
    background: rgb(255 255 255 / 8%);
}

.identite-footer .identite-sous-titre {
    color: #b9caff;
}

@media (max-width: 900px) {
    .entete {
        flex-direction: column;
        text-align: center;
    }

    .identite {
        justify-content: center;
    }

    nav {
        justify-content: center;
    }

    .proprietes {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .parcours {
        grid-template-columns: 1fr;
    }

    .accueil-hero {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-texte h1,
    .hero-description {
        margin-right: auto;
        margin-left: auto;
    }

    .hero-texte .actions {
        justify-content: center;
    }

    .hero-visuel {
        width: min(100%, 560px);
        margin: 0 auto;
    }

    .projet-points {
        grid-template-columns: 1fr;
    }

    .cartes-cours {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 600px) {
    header {
        padding: 1.5rem 1rem;
    }

    .entete {
        gap: 1rem;
    }

    nav {
        width: 100%;
    }

    nav a {
        flex: 1 1 40%;
    }

    main {
        width: 94%;
        margin: 1rem auto;
        border-radius: 0.85rem;
    }

    .proprietes,
    .demo-grid {
        grid-template-columns: 1fr;
    }

    .actions {
        flex-direction: column;
    }

    .bouton {
        width: 100%;
    }

    .hero-texte .actions {
        align-items: stretch;
    }

    .accueil-hero {
        min-height: auto;
        gap: 1rem;
        padding: 2rem 1.25rem;
    }

    .hero-texte h1 {
        font-size: clamp(2.3rem, 12vw, 3.5rem);
    }

    .hero-visuel {
        min-height: 220px;
    }

    .hero-etiquette-html {
        left: -0.25rem;
    }

    .hero-etiquette-css {
        right: -0.25rem;
    }

    .cartes-cours {
        grid-template-columns: 1fr;
    }

    .carte-cours {
        min-height: 210px;
    }

    .appel-projet,
    .navigation-lecon {
        align-items: stretch;
        flex-direction: column;
    }

    footer {
        align-items: center;
        flex-direction: column;
        text-align: center;
    }

    .demo-flex {
        align-items: stretch;
        flex-direction: column;
    }

    pre {
        padding: 1rem;
        font-size: 0.85rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        scroll-behavior: auto !important;
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}