/* =========================================================================
   app.css — BandUp design system + app shell.
   Bright & friendly: warm cream background, coral primary, teal / sun / sky /
   grape accents, rounded shapes, soft shadows. Nunito for the interface,
   Literata for reading passages.
   Light by default; dark only when the learner picks it (theme.js sets
   <html data-theme="dark">). Feature stylesheets build on these tokens.
   ========================================================================= */

:root {
    --bg: #fff9f2;
    --paper: #ffffff;
    --surface: #fff3e6;
    --fg: #1e2235;
    --muted: #626a7d;
    --line: #f0e4d6;

    --accent: #ff6b4a;          /* coral: the main action colour */
    --accent-hover: #f0532f;
    --accent-soft: #ffe7e0;
    --accent-contrast: #ffffff;

    --teal: #12a594;  --teal-soft: #dcf5f1;
    --sun: #f5a524;   --sun-soft: #fff1d6;
    --sky: #3b82f6;   --sky-soft: #e3edff;
    --grape: #8b5cf6; --grape-soft: #efe8ff;

    --ok: #14965f;  --ok-soft: #e2f6ec;
    --bad: #e5484d; --bad-soft: #fdecec;
    --evid: #fff0c2; --mark: #ffe27a; --mark-fg: #3d3000;

    --display: "Nunito", system-ui, -apple-system, "Segoe UI", sans-serif;
    --body: "Literata", Georgia, serif;
    --ui: "Nunito", system-ui, -apple-system, "Segoe UI", sans-serif;

    --nav-h: 68px;
    --radius: 14px; --radius-lg: 22px; --radius-pill: 999px;
    --shadow-1: 0 1px 2px rgba(30, 34, 53, .05), 0 2px 8px rgba(30, 34, 53, .05);
    --shadow-2: 0 8px 24px rgba(30, 34, 53, .09);
    --shadow-3: 0 18px 44px rgba(30, 34, 53, .14);
    --shadow-accent: 0 8px 20px rgba(255, 107, 74, .32);
    color-scheme: light;
}

:root[data-theme="dark"] {
    --bg: #14172a; --paper: #1c2038; --surface: #242a4a;
    --fg: #f4f1ec; --muted: #a7adc2; --line: #2f355a;
    --accent: #ff8366; --accent-hover: #ff9a82; --accent-soft: #3a2633; --accent-contrast: #1b0f0b;
    --teal: #3fd1bf; --teal-soft: #173c3e;
    --sun: #ffc054; --sun-soft: #3d3324;
    --sky: #7fb0ff; --sky-soft: #1f2d52;
    --grape: #b296ff; --grape-soft: #2c2650;
    --ok: #4cd896; --ok-soft: #173a2d; --bad: #ff7a7f; --bad-soft: #3f1f28;
    --evid: #4a3f1b; --mark: #6b5617; --mark-fg: #fff3bf;
    --shadow-1: 0 1px 2px rgba(0, 0, 0, .4); --shadow-2: 0 8px 24px rgba(0, 0, 0, .45); --shadow-3: 0 18px 44px rgba(0, 0, 0, .55);
    --shadow-accent: 0 8px 20px rgba(255, 131, 102, .25);
    color-scheme: dark;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    background: var(--bg);
    color: var(--fg);
    font-family: var(--ui);
    font-size: 16px;
    line-height: 1.55;
    -webkit-font-smoothing: antialiased;
}

/* Elements hidden with the hidden attribute stay hidden even when a class sets display. */
[hidden] { display: none !important; }

.wrap {
    padding-left: max(16px, env(safe-area-inset-left, 0px));
    padding-right: max(16px, env(safe-area-inset-right, 0px));
}

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

:focus-visible {
    outline: 3px solid color-mix(in srgb, var(--accent) 55%, transparent);
    outline-offset: 2px;
    border-radius: 8px;
}

h1, h2, h3 { font-family: var(--display); letter-spacing: -.01em; }

/* ---- Buttons ---------------------------------------------------------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font: 700 .95rem var(--ui);
    cursor: pointer;
    border-radius: var(--radius-pill);
    padding: 10px 20px;
    border: 2px solid var(--line);
    background: var(--paper);
    color: var(--fg);
    text-decoration: none;
    transition: background .15s ease, box-shadow .15s ease, border-color .15s ease, transform .08s ease;
}
.btn:hover { border-color: color-mix(in srgb, var(--accent) 40%, var(--line)); }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .55; cursor: not-allowed; }
.btn--primary {
    background: var(--accent);
    border-color: var(--accent);
    color: var(--accent-contrast);
    box-shadow: var(--shadow-accent);
}
.btn--primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); }
.btn--lg { padding: 14px 28px; font-size: 1.05rem; }
.btn--text { border-color: transparent; background: transparent; color: var(--accent); }
.btn--text:hover { background: var(--accent-soft); border-color: transparent; }
.btn--danger { color: var(--bad); border-color: transparent; background: transparent; }
.btn--danger:hover { background: var(--bad-soft); border-color: transparent; }

/* ---- App bar (public navbar) ----------------------------------------- */
.app-nav {
    position: sticky;
    top: 0;
    z-index: 20;
    background: color-mix(in srgb, var(--bg) 86%, transparent);
    backdrop-filter: saturate(160%) blur(10px);
    border-bottom: 1px solid var(--line);
}
.app-nav__inner {
    max-width: 1180px;
    margin: 0 auto;
    min-height: var(--nav-h);
    display: flex;
    align-items: center;
    gap: 16px;
}
.app-nav__brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font: 800 1.3rem var(--display);
    color: var(--fg);
    text-decoration: none;
}
.app-nav__name span { color: var(--accent); }
.brand-mark { width: 34px; height: 34px; flex: none; }

.app-nav__menu {
    list-style: none;
    display: flex;
    align-items: center;
    gap: 4px;
    margin: 0 0 0 auto;
    padding: 0;
}
.app-nav__item { display: flex; }
.app-nav__account { gap: 4px; align-items: center; }
.app-nav__user {
    color: var(--muted); font-weight: 700; font-size: .9rem; padding: 0 6px; max-width: 14ch;
    overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.app-nav__signout { background: none; border: 0; font: inherit; cursor: pointer; }
.app-nav__link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 9px 16px;
    border-radius: var(--radius-pill);
    font-weight: 700;
    text-decoration: none;
    color: var(--fg);
    transition: background .15s ease, color .15s ease;
}
.app-nav__link:hover { background: var(--surface); }
.app-nav__link.is-active { color: var(--accent); background: var(--accent-soft); }
.app-nav__link--disabled { color: var(--muted); cursor: not-allowed; }
.app-nav__link--disabled:hover { background: transparent; }
.app-nav__cta { background: var(--accent); color: var(--accent-contrast); box-shadow: var(--shadow-accent); }
.app-nav__cta:hover { background: var(--accent-hover); }
.app-nav__badge {
    font: 800 .6rem var(--ui); letter-spacing: .08em; text-transform: uppercase;
    padding: 3px 8px; border-radius: var(--radius-pill);
    background: var(--sun-soft); color: color-mix(in srgb, var(--sun) 70%, var(--fg));
}

/* Icon buttons (theme toggle, hamburger). */
.icon-btn {
    display: inline-grid;
    place-items: center;
    width: 42px; height: 42px;
    border-radius: 50%;
    border: 2px solid transparent;
    background: transparent;
    color: var(--fg);
    font-size: 1.1rem;
    cursor: pointer;
    transition: background .15s ease;
}
.icon-btn:hover { background: var(--surface); }

.app-nav__toggle {
    display: none;
    margin-left: auto;
    width: 42px; height: 42px;
    border: 2px solid var(--line);
    border-radius: var(--radius);
    background: var(--paper);
    cursor: pointer;
    position: relative;
}
.app-nav__bars, .app-nav__bars::before, .app-nav__bars::after {
    position: absolute; left: 50%; width: 18px; height: 2px; border-radius: 2px;
    background: var(--fg); transform: translateX(-50%); transition: transform .2s ease;
}
.app-nav__bars { top: 50%; transform: translate(-50%, -50%); }
.app-nav__bars::before { content: ""; top: -6px; }
.app-nav__bars::after { content: ""; top: 6px; }

@media (max-width: 720px) {
    .app-nav__toggle { display: inline-block; }
    .app-nav__menu {
        display: none;
        position: absolute; left: 0; right: 0; top: var(--nav-h);
        flex-direction: column; align-items: stretch; gap: 4px;
        margin: 0; padding: 12px;
        background: var(--paper); border-bottom: 1px solid var(--line); box-shadow: var(--shadow-2);
    }
    .app-nav.open .app-nav__menu { display: flex; }
    .app-nav__item, .app-nav__link { width: 100%; }
}

@media (prefers-reduced-motion: reduce) { * { transition: none !important; animation: none !important; } }

/* ---- Shared bits ------------------------------------------------------ */
.page { max-width: 1180px; margin: 0 auto; }
.eyebrow {
    display: inline-block; font: 800 .75rem var(--ui); letter-spacing: .08em; text-transform: uppercase;
    color: var(--accent); background: var(--accent-soft); padding: 5px 12px; border-radius: var(--radius-pill);
}
.section-title { font: 800 1.6rem/1.2 var(--display); margin: 0 0 6px; }
.section-sub { color: var(--muted); margin: 0 0 22px; }

/* Exercise cards (home + catalog): a cover image on top, details below. */
.ex-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 24px; }
@media (max-width: 960px) { .ex-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 600px) { .ex-grid { grid-template-columns: 1fr; } }
.ex-card {
    display: flex; flex-direction: column;
    background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius-lg);
    overflow: hidden; color: inherit; text-decoration: none;
    box-shadow: var(--shadow-1);
    transition: box-shadow .2s ease, transform .2s ease;
}
.ex-card:hover, .ex-card:focus-visible { box-shadow: var(--shadow-3); transform: translateY(-4px); }
.ex-cover { position: relative; aspect-ratio: 16 / 9; background: var(--surface); }
.ex-cover img { width: 100%; height: 100%; object-fit: cover; display: block; }
.ex-cover .ex-done {
    position: absolute; top: 12px; right: 12px;
    font: 800 .78rem var(--ui); padding: 4px 11px; border-radius: var(--radius-pill);
    background: var(--ok); color: #fff;
}
.ex-body { display: flex; flex-direction: column; gap: 10px; padding: 16px 18px 18px; flex: 1; }
.ex-card h2, .ex-card h3 { font: 800 1.12rem/1.3 var(--display); margin: 0; }
.ex-meta { display: flex; flex-wrap: wrap; gap: 6px; }
.ex-meta span {
    font: 700 .78rem var(--ui); padding: 3px 10px; border-radius: var(--radius-pill);
    background: var(--surface); color: var(--muted);
}
.ex-meta .ex-meta__level { background: var(--accent-soft); color: var(--accent); }
.ex-topics { font-size: .85rem; color: var(--muted); }
.ex-progress { margin-top: auto; font: 800 .88rem var(--ui); color: var(--ok); }
.ex-progress--new { color: var(--accent); }

.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 16px; }
.badge {
    font: 800 .6rem var(--ui); letter-spacing: .08em; text-transform: uppercase;
    padding: 3px 9px; border-radius: var(--radius-pill); background: var(--sun-soft);
    color: color-mix(in srgb, var(--sun) 65%, var(--fg));
}

.site-foot {
    max-width: 1180px; margin: 56px auto 0; padding: 28px 16px 40px;
    display: flex; gap: 12px; justify-content: space-between; flex-wrap: wrap;
    border-top: 1px solid var(--line); color: var(--muted); font-size: .9rem;
}

/* ---- Home ------------------------------------------------------------- */
.home { max-width: 1180px; margin: 0 auto; }
.hero {
    display: grid; grid-template-columns: 1.1fr .9fr; gap: 40px; align-items: center;
    padding: 56px 0 40px;
}
.hero__title { font: 800 clamp(2.2rem, 5vw, 3.4rem)/1.08 var(--display); margin: 16px 0 16px; text-wrap: balance; }
.hero__title em { font-style: normal; color: var(--accent); }
.hero__lead { color: var(--muted); font-size: 1.15rem; margin: 0 0 28px; max-width: 48ch; }
.hero__actions { display: flex; gap: 12px; flex-wrap: wrap; }
.hero__art { position: relative; }
.hero__art img { width: 100%; display: block; border-radius: var(--radius-lg); box-shadow: var(--shadow-3); }
.hero__sticker {
    position: absolute; background: var(--paper); border-radius: var(--radius); padding: 10px 14px;
    box-shadow: var(--shadow-2); font: 800 .9rem var(--ui); display: flex; gap: 8px; align-items: center;
}
.hero__sticker--a { left: -18px; bottom: 28px; }
.hero__sticker--b { right: -12px; top: 22px; }
.hero__sticker i { font-style: normal; width: 28px; height: 28px; border-radius: 50%; display: grid; place-items: center; color: #fff; }
@media (max-width: 860px) {
    .hero { grid-template-columns: 1fr; padding-top: 32px; }
    .hero__sticker--a { left: 10px; } .hero__sticker--b { right: 10px; }
}

.steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 18px; margin: 24px 0 56px; }
.step { background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius-lg); padding: 22px; box-shadow: var(--shadow-1); }
.step__icon { width: 46px; height: 46px; border-radius: 14px; display: grid; place-items: center; font-size: 1.35rem; margin-bottom: 14px; }
.step h3 { margin: 0 0 6px; font: 800 1.08rem var(--display); }
.step p { margin: 0; color: var(--muted); font-size: .95rem; }

.home-section { margin-bottom: 56px; }
.home-section__head { display: flex; justify-content: space-between; align-items: end; gap: 12px; flex-wrap: wrap; margin-bottom: 18px; }
.home-section__head .section-sub { margin: 0; }

.skills { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px; }
.skill {
    display: flex; gap: 16px; align-items: center; padding: 20px; border-radius: var(--radius-lg);
    text-decoration: none; color: inherit; border: 1px solid var(--line); background: var(--paper);
    transition: box-shadow .2s, transform .2s;
}
a.skill:hover { box-shadow: var(--shadow-2); transform: translateY(-2px); }
.skill__icon { width: 54px; height: 54px; border-radius: 16px; display: grid; place-items: center; font-size: 1.6rem; flex: none; }
.skill h3 { margin: 0 0 4px; font: 800 1.1rem var(--display); display: flex; gap: 8px; align-items: center; }
.skill p { margin: 0; color: var(--muted); font-size: .92rem; }
.skill--soon { opacity: .75; }
.skill { padding: 26px; }
.skill__go { margin-left: auto; font: 800 1.4rem var(--ui); color: var(--accent); transition: transform .2s; }
a.skill:hover .skill__go { transform: translateX(4px); }
a.skill { border: 2px solid var(--accent-soft); }

/* The reading page is full-height; its footer would only get in the way. */
body:has(.reading) .site-foot { display: none; }

/* Colour helpers (no inline style attributes: the Content-Security-Policy forbids them). */
.bg-ok { background: var(--ok); } .bg-sun { background: var(--sun); }
.bg-sky-soft { background: var(--sky-soft); } .bg-sun-soft { background: var(--sun-soft); }
.bg-teal-soft { background: var(--teal-soft); } .bg-accent-soft { background: var(--accent-soft); }
.bg-grape-soft { background: var(--grape-soft); }