:root {
    --fond-site: #0f172a;
    --fond-carte: #111827;
    --fond-input: #020617;

    --bleu: #2563eb;
    --bleu-clair: #38bdf8;
    --accent: #f59e0b;

    --texte: #f8fafc;
    --texte-secondaire: #cbd5e1;
    --bordure: #334155;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: radial-gradient(circle at top, #1e293b 0%, var(--fond-site) 45%);
    color: var(--texte);
}

/* =========================
   HEADER
========================= */

header {
    text-align: center;
    padding: 40px 20px 20px;
}

h1 {
    margin: 0;
    color: white;
    font-size: 42px;
    letter-spacing: 1px;
}

h1::after {
    content: "";
    display: block;
    width: 90px;
    height: 4px;
    background: linear-gradient(
        90deg,
        var(--bleu),
        var(--bleu-clair),
        var(--accent)
    );
    margin: 15px auto 0;
    border-radius: 999px;
}

.sous-titre {
    color: var(--texte-secondaire);
    margin-top: 15px;
    font-size: 18px;
}

/* =========================
   GRID
========================= */

main {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 35px;

    max-width: 1300px;
    margin: 40px auto;
    padding: 20px;
}

/* =========================
   CARTES
========================= */

#presentation,
#commencer,
#dons,
#modeles,
#seo {
    background: rgba(17, 24, 39, 0.95);

    border: 1px solid var(--bordure);
    border-radius: 18px;

    padding: 30px;

    box-shadow:
        0 12px 30px rgba(0,0,0,0.25);

    transition: 0.2s ease;
}

#presentation:hover,
#commencer:hover,
#dons:hover,
#modeles:hover,
#seo:hover {
    transform: translateY(-2px);
}

/* =========================
   TITRES
========================= */

h2 {
    margin-top: 0;
    color: white;
    font-size: 28px;
}

h2::after {
    content: "";
    display: block;
    width: 60px;
    height: 3px;

    margin-top: 10px;

    background: linear-gradient(
        90deg,
        var(--bleu),
        var(--bleu-clair)
    );

    border-radius: 999px;
}

/* =========================
   TEXTE
========================= */

p {
    color: var(--texte-secondaire);
    line-height: 1.7;
    font-size: 17px;
}

/* =========================
   BOUTON COMMENCER
========================= */

#buttoncommencer {
    margin-top: 35px;

    background: linear-gradient(
        135deg,
        var(--bleu),
        var(--bleu-clair)
    );

    color: white;

    border: none;
    border-radius: 14px;

    padding: 18px;

    font-size: 18px;
    font-weight: bold;

    cursor: pointer;

    text-align: center;

    transition: 0.2s ease;

    box-shadow:
        0 10px 25px rgba(37,99,235,0.25);
}

#buttoncommencer:hover {
    transform: translateY(-3px) scale(1.02);

    box-shadow:
        0 15px 35px rgba(56,189,248,0.35);
}

#com2 {
    margin: 0;
    color: white;
}

/* =========================
   DON
========================= */

#bouton-don-popup {
    display: inline-block;

    margin-top: 20px;

    padding: 14px 22px;

    border-radius: 12px;

    text-decoration: none;
    font-weight: bold;

    color: white;

    background: linear-gradient(
        135deg,
        var(--bleu),
        var(--bleu-clair)
    );

    transition: 0.2s ease;
}

#bouton-don-popup:hover {
    transform: translateY(-2px);
}

/* =========================
   MODELES
========================= */

#modeles h2 {
    margin-bottom: 25px;
}

.grille-modeles {
    display: grid;

    grid-template-columns: repeat(4, 1fr);

    gap: 18px;
}

.b1,
.b2,
.b3,
.b4 {
    width: 100%;
    height: 240px;

    overflow: hidden;

    border-radius: 14px;

    border: 1px solid var(--bordure);

    background: var(--fond-input);

    transition: 0.2s ease;

    cursor: pointer;
}

.b1:hover,
.b2:hover,
.b3:hover,
.b4:hover {
    transform: translateY(-5px);

    border-color: var(--bleu-clair);

    box-shadow:
        0 12px 30px rgba(56,189,248,0.25);
}

.b1 img,
.b2 img,
.b3 img,
.b4 img {
    width: 100%;
    height: 100%;
    object-fit: cover;

    display: block;
}

/* =========================
   SEO
========================= */

#seo {
    grid-column: span 2;
}

/* =========================
   FOOTER
========================= */

footer {
    text-align: center;

    padding: 30px;

    color: var(--texte-secondaire);

    border-top: 1px solid var(--bordure);

    margin-top: 50px;
}

/* =========================
   RESPONSIVE
========================= */

@media (max-width: 1000px) {

    main {
        grid-template-columns: 1fr;
    }

    #seo {
        grid-column: span 1;
    }

    .grille-modeles {
        grid-template-columns: repeat(2, 1fr);
    }

    h1 {
        font-size: 34px;
    }
}

@media (max-width: 600px) {

    .grille-modeles {
        grid-template-columns: 1fr;
    }

    .b1,
    .b2,
    .b3,
    .b4 {
        height: 300px;
    }
}


.outil-mini:hover .nom-outil {
    color: #38bdf8;

    text-shadow:
        0 0 5px #38bdf8,
        0 0 10px #38bdf8,
        0 0 20px #38bdf8;

    transform: translateY(-2px);
}

.lien-outil {
    text-decoration: none;
    display: block;
}

#sites {
    background: rgba(17, 24, 39, 0.95);
    border: 1px solid var(--bordure);
    border-radius: 18px;
    padding: 30px;
    box-shadow: 0 12px 30px rgba(0,0,0,0.25);
}