/* Palette : modifier ces deux variables pour essayer d'autres couleurs. */
:root {
    --color_primary: var(--brand-green);
    --color_secondary: var(--brand-sage);
    /*--color_primary: #164b3b;
    --color_secondary: #e8ebe9;*/
    --color_surface: #ffffff;
    --color_on_primary: #ffffff;
    --color_background: #f5f6f7;
    /* Fond cahier : teinte, lignes et marge réglables indépendamment du thème. */
    --paper_color: #faf9f6;
    --paper_line: rgba(112, 142, 167, .16);
    --paper_margin_color: rgba(185, 112, 112, .22);
    --paper_line_spacing: 30px;
    --paper_margin_position: clamp(10px, 2.2vw, 32px);
    --color_text: #252a30;
    --color_muted: #606873;
    --color_border: #dce0e5;
    --color_soft: color-mix(in srgb, var(--color_primary) 6%, var(--color_surface));
    --color_secondary_soft: color-mix(in srgb, var(--color_secondary) 12%, var(--color_surface));
    --color_hover: color-mix(in srgb, var(--color_primary) 85%, #000);
    --color_reader: #29302d;
    --color_error: #972e37;
    --corner_cut: 10px;
    --shadow: 0 12px 32px color-mix(in srgb, var(--color_primary) 7%, transparent);
    color-scheme: light;
}
* { box-sizing: border-box; }
body {
    margin: 0;
    min-height: 100vh;
    background-color: var(--paper_color);
    background-image:
        linear-gradient(to right, transparent var(--paper_margin_position), var(--paper_margin_color) var(--paper_margin_position), var(--paper_margin_color) calc(var(--paper_margin_position) + 1px), transparent calc(var(--paper_margin_position) + 1px)),
        repeating-linear-gradient(to bottom, transparent 0, transparent calc(var(--paper_line_spacing) - 1.5px), var(--paper_line) calc(var(--paper_line_spacing) - 1.5px), var(--paper_line) var(--paper_line_spacing)),
        radial-gradient(ellipse at 20% 10%, rgba(255, 255, 255, .7), transparent 65%);
    color: var(--color_text);
    font: 16px/1.65 system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
a { color: var(--color_primary); text-underline-offset: .22em; }
a:hover { color: var(--color_hover); }
:focus-visible { outline: 3px solid var(--color_primary); outline-offset: 4px; }
h1, h2, h3 { line-height: 1.2; letter-spacing: -.035em; overflow-wrap: anywhere; }
h1 { font-size: clamp(2rem, 4vw, 3.3rem); margin: 0 0 1.2rem; }
h2 { font-size: clamp(1.3rem, 2.5vw, 1.9rem); }
p { max-width: 75ch; }
main { max-width: 1440px; margin: auto; padding: clamp(1rem, 4vw, 3rem); min-height: 75vh; }
main > form { max-width: 720px; padding: clamp(1rem, 3vw, 2rem); background: var(--color_surface); border: 1px solid var(--color_border); border-radius: 1rem; box-shadow: var(--shadow); }
main > article, .panel { background: var(--color_surface); border: 1px solid var(--color_border); border-radius: 1rem; padding: clamp(1.2rem, 3vw, 2rem); margin: 1rem 0; box-shadow: var(--shadow); }
label { font-weight: 600; }
input:not([type=checkbox]):not([type=radio]):not([type=hidden]), select, textarea { display: block; width: 100%; max-width: 100%; padding: .8rem 1rem; margin: .35rem 0; border: 1px solid var(--color_border); border-radius: .6rem; background: var(--color_surface); color: var(--color_text); font: inherit; }
input[type=checkbox], input[type=radio] { accent-color: var(--color_primary); width: 1.15rem; height: 1.15rem; vertical-align: middle; }
textarea { min-height: 150px; resize: vertical; }
fieldset { min-width: 0; margin: 0 0 1rem; padding: 0; border: 0; }
button, .action { display: inline-flex; align-items: center; justify-content: center; gap: .5rem; min-height: 44px; border: 1px solid var(--color_primary); border-radius: .6rem; padding: .7rem 1.15rem; background: var(--color_primary); color: var(--color_on_primary); font: inherit; font-weight: 600; text-decoration: none; cursor: pointer; }
button:hover, .action:hover { background: var(--color_hover); color: var(--color_on_primary); }
button:disabled { opacity: .5; cursor: default; }
.secondary { background: var(--color_surface); color: var(--color_primary); }
.secondary:hover { background: var(--color_soft); color: var(--color_primary); }
.errorlist { color: var(--color_error); }
.helptext { display: block; color: var(--color_muted); font-size: .875rem; }
.site-nav { background: var(--color_surface); border-bottom: 1px solid var(--color_border); padding: 1rem clamp(1rem, 4vw, 3rem); display: flex; align-items: center; gap: 1rem; flex-wrap: wrap; }
.site-brand { font-size: 1.2rem; font-weight: 800; letter-spacing: -.04em; text-decoration: none; margin-right: auto; }
.site-nav a:not(.site-brand) { padding: .5rem; border-radius: .5rem; text-decoration: none; font-size: .9rem; font-weight: 600; }
.site-nav a:hover { background: var(--color_soft); }
.site-nav form { margin: 0; }
.site-nav button { font-size: .85rem; padding: .5rem .75rem; }
.skip-link { position: absolute; left: 1rem; top: -100px; z-index: 100; background: var(--color_surface); padding: .75rem; }
.skip-link:focus { top: 1rem; }
.site-footer { max-width: 1380px; margin: 1rem auto; padding: 1.5rem; border-top: 1px solid var(--color_border); color: var(--color_muted); display: flex; justify-content: space-between; flex-wrap: wrap; gap: 1rem; font-size: .9rem; }
.hero { background: var(--color_surface); color: var(--color_text); padding: clamp(2rem, 6vw, 5rem); border-radius: 1.5rem; margin-bottom: 2rem; }
.hero h1 { max-width: 18ch; }
.hero p { max-width: 55ch; }
.hero-actions { display: flex; gap: .75rem; flex-wrap: wrap; margin-top: 1.75rem; }
.hero .action { background: var(--color_surface); color: var(--color_primary); }
.hero .secondary { background: var(--color_background); color: var(--color_text); border-color: var(--color_border); }
.hero .action:hover { background: var(--color_soft); color: var(--color_primary); }
.catalog-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 280px), 1fr)); gap: 1.25rem; }
.catalog-grid article { margin: 0; display: flex; flex-direction: column; align-items: flex-start; }
.catalog-grid article > a { margin-top: auto; font-weight: 700; }
.pack-price { font-size: 2rem; font-weight: 750; color: var(--color_primary); }
@media (max-width: 700px) { .site-nav { gap: .4rem; } .site-brand { flex-basis: 100%; } main { padding-top: 1.5rem; } }

/* Découpes obliques : le texte reste droit et les contrôles gardent leur hauteur. */
button, .action {
    border-radius: 0;
    padding-inline: calc(1rem + var(--corner_cut));
    clip-path: polygon(var(--corner_cut) 0, 100% 0, calc(100% - var(--corner_cut)) 100%, 0 100%);
}
button:focus-visible, .action:focus-visible {
    outline: 3px solid currentColor;
    outline-offset: -5px;
    text-decoration: underline;
}
.site-nav { border-bottom: 1px solid var(--color_border); gap: .5rem; }
.site-nav a:not(.site-brand) {
    position: relative;
    border-radius: 0;
    padding: .65rem calc(.75rem + var(--corner_cut));
    min-height: 44px;
    background: var(--color_background);
    clip-path: polygon(var(--corner_cut) 0, 100% 0, calc(100% - var(--corner_cut)) 100%, 0 100%);
}
.site-nav a:not(.site-brand)::before {
    content: none;
    position: absolute;
    left: 0;
    top: 25%;
    height: 50%;
    border-left: 2px solid var(--color_border);
    transform: skewX(-20deg);
    pointer-events: none;
}
.site-nav a:not(.site-brand):hover::before { border-color: var(--color_primary); }
.site-nav a:focus-visible { outline-offset: -5px; text-decoration: underline; }
.site-nav button { padding-inline: 1rem; }
.hero, .panel, main > article, main > form { border-radius: 0; }
.hero { position: relative; border-left: .5rem solid var(--color_border); }
.hero::after {
    content: '';
    display: block;
    width: 5rem;
    height: .8rem;
    margin-top: 2rem;
    background: repeating-linear-gradient(115deg, var(--color_secondary) 0 5px, transparent 5px 13px);
    pointer-events: none;
}
input:not([type=checkbox]):not([type=radio]), select, textarea { border-radius: 0; }

.subjects-heading { display: flex; justify-content: space-between; align-items: end; flex-wrap: wrap; gap: 1rem; margin-bottom: 2rem; }
.subjects-heading p { color: var(--color_muted); }
.subject-count, .subject-level { display: inline-block; padding: .35rem .8rem; background: var(--color_background); color: var(--color_muted); font-size: .85rem; }
.subject-card { border-top: 2px solid var(--color_border); }
.subject-card:hover { border-top-color: var(--color_primary); }
.subject-card h2 { margin: 1.5rem 0; }
.subject-date { width: 100%; margin: 0 0 2rem; padding-top: 1rem; border-top: 1px solid var(--color_border); }
.subject-date dt { font-size: .8rem; color: var(--color_muted); }
.subject-date dd { margin: .25rem 0 0; font-weight: 600; }
.subject-card .action { background: var(--color_background); color: var(--color_text); border-color: var(--color_border); }
.subject-card .action:hover { background: var(--color_soft); color: var(--color_primary); }

/* Contour complet du parallélogramme, indépendant du fond intérieur. */
.hero::after { content: none; }
button, a.action, .library-shell .action {
    --button_fill: var(--color_primary);
    position: relative;
    isolation: isolate;
    border: 0;
    background: var(--color_primary);
}
.hero a.action, a.action.secondary, .subject-card a.action {
    --button_fill: var(--color_surface);
    background: var(--color_primary);
    color: var(--color_primary);
}
.hero a.action:hover, a.action.secondary:hover, .subject-card a.action:hover {
    background: var(--color_primary);
    color: var(--color_primary);
}
button::before, a.action::before {
    content: '';
    position: absolute;
    inset: 2px;
    z-index: -1;
    background: var(--button_fill);
    clip-path: polygon(var(--corner_cut) 0, 100% 0, calc(100% - var(--corner_cut)) 100%, 0 100%);
    pointer-events: none;
}
button::after, a.action::after {
    content: '';
    position: absolute;
    top: 5px;
    left: calc(var(--corner_cut) + 5px);
    right: calc(var(--corner_cut) + 5px);
    height: 3px;
    background: var(--color_secondary);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 220ms ease-out;
    pointer-events: none;
}
button:not(:disabled):hover::after, a.action:hover::after,
button:focus-visible::after, a.action:focus-visible::after { transform: scaleX(1); }
.pack-purchase { width: 100%; display: flex; align-items: center; justify-content: space-between; gap: .9rem; margin-top: auto; padding-top: 1.5rem; }
.pack-purchase .pack-price { margin: 0; font-size: clamp(1.4rem, 3vw, 2rem); white-space: nowrap; }
.pack-purchase .action { flex-shrink: 0; }
.pack-purchase::before { content: ''; order: 1; height: 2rem; border-left: 1px solid var(--color_border); transform: skewX(-18deg); margin-left: auto; }
.pack-purchase .action { order: 2; }
@media (prefers-reduced-motion: reduce) { button::after, a.action::after { transition: none; } }
.account-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.5rem; align-items: stretch; }
.account-panel h1, .account-panel h2 { font-size: clamp(1.3rem, 2.5vw, 1.9rem); margin: 0 0 1.5rem; }
.account-panel { min-width: 0; }
.account-panel dd { margin: 0 0 .75rem; overflow-wrap: anywhere; }
.account-panel dt { font-size: .85rem; color: var(--color_muted); }

/* Rappels de la couleur secondaire : petits accents sur des surfaces neutres. */
.site-nav { border-bottom: 2px solid var(--color_secondary); }
.site-nav a:not(.site-brand):hover,
.site-nav a:not(.site-brand):focus-visible { background: var(--color_secondary_soft); }
main > h1::after,
.subjects-heading h1::after,
.library-heading h1::after {
    content: '';
    display: block;
    width: 3rem;
    height: 4px;
    margin-top: .7rem;
    background: var(--color_secondary);
    transform: skewX(-18deg);
}
.panel, main > article, main > form {
    border-top: 3px solid var(--color_primary);
    box-shadow: var(--shadow);
}
.subject-count, .subject-level { background: var(--color_secondary_soft); color: var(--color_text); }
.pack-purchase::before { border-left: 2px solid var(--color_secondary); }
.site-footer { border-top-color: var(--color_secondary); }
@media (max-width: 800px) { .account-grid { grid-template-columns: 1fr; } }

/* Navigation progressive : sans JavaScript, tous les liens restent accessibles. */
.navigation-links { display: flex; flex-wrap: wrap; align-items: center; gap: .5rem; min-width: 0; }
[hidden] { display: none !important; }
.site-nav a:not(.site-brand) { display: inline-flex; align-items: center; }
main, .panel, .catalog-grid > *, .hero-actions > *, .account-grid > * { min-width: 0; }
main p, main li, main dd, main a { overflow-wrap: anywhere; }
button, .action { max-width: 100%; white-space: normal; text-align: center; }
@media (max-width: 900px) {
    .site-nav { justify-content: space-between; padding: .85rem 1rem; gap: .75rem; }
    .site-nav .site-brand { flex-basis: auto; margin-right: 0; }
    .navigation-links { flex-basis: 100%; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); padding-top: .75rem; border-top: 1px solid var(--color_border); }
    .navigation-links a, .navigation-links button { width: 100%; min-height: 48px; justify-content: center; }
    .navigation-links form { min-width: 0; }
}
@media (max-width: 600px) {
    main { padding: 1.5rem 1rem; }
    .hero { padding: 1.5rem 1.1rem; }
    .hero h1 { font-size: clamp(1.8rem, 8vw, 2.5rem); max-width: none; }
    .hero-actions { flex-direction: column; align-items: stretch; }
    .hero-actions .action { width: 100%; }
    .catalog-grid, .account-grid { grid-template-columns: minmax(0, 1fr); gap: 1rem; }
    .panel, main > form, main > article { padding: 1.1rem; }
    .account-panel form button, main > form > button { width: 100%; }
    .subjects-heading { align-items: start; gap: .5rem; }
    .pack-purchase { gap: .5rem; }
    .pack-purchase .action { padding-inline: calc(.5rem + var(--corner_cut)); }
    .site-footer { margin: 0 1rem; padding: 1rem 0; }
    input:not([type=checkbox]):not([type=radio]), select, textarea { font-size: 16px; min-height: 44px; }
}
@media (pointer: coarse) { button, .action { min-height: 48px; } }
@media (max-width: 900px) {
    .site-nav { position: relative; z-index: 20; }
    .site-nav .nav-toggle { order: -1; }
    .site-nav .site-brand { margin-left: auto; }
    .navigation-links {
        width: min(320px, 90vw);
        max-height: calc(100dvh - 90px);
        overflow-y: auto;
        overscroll-behavior: contain;
        grid-template-columns: minmax(0, 1fr);
        padding: 1rem;
        background: var(--color_surface);
        border: 1px solid var(--color_border);
        box-shadow: var(--shadow);
    }
    .navigation-links a { justify-content: flex-start; }
    .navigation-ready .navigation-links { position: absolute; top: 100%; left: 0; }
}