/* Learnora landing page.
 *
 * The look is the exercise book (webapp/DESIGN.md §0.8): white paper, blue-black
 * ink, feint blue ruled lines, a red margin, red-pen corrections and an ochre
 * tick. Each colour below has one job, and the job is in its name. Teal is the
 * brand and the only colour for primary actions.
 */

/* --- Tokens -------------------------------------------------------------- */

:root {
    color-scheme: light;

    /* Surfaces */
    --paper: #fcfcf9;        /* the page */
    --paper-sunk: #f2f3ee;   /* a recessed band */
    --sheet: #ffffff;        /* an exercise-book page: demos, cards */

    /* Ink */
    --ink: #17202e;          /* body text and headings */
    --ink-2: #4a5465;        /* secondary text */
    --ink-3: #636c7a;        /* meta, captions */

    /* The book */
    --rule: #d3e0ef;         /* feint ruled line */
    --margin: #e8a7a7;       /* margin line, decoration only */
    --pen: #b42f22;          /* red-pen corrections: a mistake */
    --pen-soft: #fbeceb;
    --tick: #c08a1c;         /* ochre tick in the mark */
    --highlight: #fbe39a;    /* the one highlighter stroke */
    --ok: #1b7a4a;           /* a right answer */
    --ok-soft: #e7f4ec;

    /* Brand and action */
    --brand: #0e6b5f;
    --brand-hover: #0a564c;
    --brand-soft: #e2f0ed;
    --on-brand: #ffffff;
    --focus: #1f5fbf;

    /* Lines and shadow */
    --line: #e1e3dc;
    --line-strong: #c9ccc3;
    --shadow-sheet: 0 1px 0 rgba(23, 32, 46, 0.04), 0 10px 30px -14px rgba(23, 32, 46, 0.22);
    /* Stickers: a hard ink edge and an offset shadow, like a label stuck
       on a page. Used by buttons, demo sheets and the eyebrow labels. */
    --edge: #17202e;
    --hard: #17202e;
    --hard-sm: 3px 3px 0 var(--hard);
    --hard-lg: 7px 7px 0 var(--hard);

    /* Bands: the exercise book's cover, and a highlighter-yellow page.
       Text on both is fixed, so it stays readable in either theme. */
    --cover: #0d4a42;
    --cover-ink: #f6f3ea;
    --cover-ink-2: #c2dcd5;
    --cover-mark: #ffd34d;   /* highlighter on the cover */
    --band-yellow: #ffd84d;
    --band-ink: #17202e;

    /* Subject spines, as in the app's lists */
    --spine-1: #0e6b5f;
    --spine-2: #b42f22;
    --spine-3: #3d5fa8;
    --spine-4: #c08a1c;
    --spine-5: #7a4f9a;
    --spine-6: #2f7f8f;
    --spine-7: #8a5a2b;

    /* Type */
    --font-display: "Literata", Georgia, "Times New Roman", serif;
    --font-ui: "Literata", Georgia, "Times New Roman", serif;
    --font-hand: "Caveat", "Segoe Print", "Comic Sans MS", cursive;
    --fs-hero: clamp(2.75rem, 1.5rem + 3.9vw, 5rem);
    --fs-h2: clamp(2.1rem, 1.4rem + 2.6vw, 3.5rem);
    --fs-h3: 1.25rem;
    --fs-lede: clamp(1.06rem, 1rem + 0.35vw, 1.22rem);
    --fs-body: 1rem;
    --fs-small: 0.875rem;
    --fs-hand: 1.35rem;

    /* Space (4px steps) */
    --s-1: 0.25rem;
    --s-2: 0.5rem;
    --s-3: 0.75rem;
    --s-4: 1rem;
    --s-5: 1.5rem;
    --s-6: 2rem;
    --s-7: 3rem;
    --s-8: 4.5rem;
    --s-9: 6.5rem;

    /* Shape */
    --r-sm: 6px;
    --r-md: 10px;
    --r-lg: 14px;
    --r-pill: 999px;

    /* Motion: one easing, three durations */
    --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
    --dur-fast: 140ms;
    --dur: 240ms;
    --dur-slow: 420ms;

    --wrap: 1160px;
    --gutter: clamp(1rem, 0.6rem + 2vw, 2rem);
    --rule-gap: 2rem; /* line height of the ruled paper */
}

@media (prefers-color-scheme: dark) {
    :root {
        color-scheme: dark;
        --paper: #12161d;
        --paper-sunk: #0e1117;
        --sheet: #181d26;
        --ink: #e9edf3;
        --ink-2: #b8c0cc;
        --ink-3: #939dab;
        --rule: #263247;
        --margin: #6d3a3a;
        --pen: #ff8d7f;
        --pen-soft: #3a2224;
        --tick: #e4b54f;
        --highlight: rgba(247, 205, 90, 0.34);
        --ok: #6fd39c;
        --ok-soft: #173326;
        --brand: #4fc3ae;
        --brand-hover: #74d4c2;
        --brand-soft: #16302c;
        --on-brand: #06201b;
        --focus: #8ab4ff;
        --line: #283040;
        --line-strong: #3a4456;
        --shadow-sheet: 0 1px 0 rgba(0, 0, 0, 0.3), 0 14px 34px -18px rgba(0, 0, 0, 0.7);
        /* A black offset vanishes on a dark page; teal keeps the sticker. */
        --edge: #6b7a90;
        --hard: #2b8a7b;
        --cover: #0f3631;
        --spine-1: #4fc3ae;
        --spine-2: #ff8d7f;
        --spine-3: #8aa8ec;
        --spine-4: #e4b54f;
        --spine-5: #c39be0;
        --spine-6: #6fc4d4;
        --spine-7: #d6a374;
    }
}

/* --- Base ---------------------------------------------------------------- */

*,
*::before,
*::after {
    box-sizing: border-box;
}

/* Components below set display, which would otherwise beat [hidden]. */
[hidden] {
    display: none !important;
}

html {
    -webkit-text-size-adjust: 100%;
    scroll-behavior: smooth;
}

body {
    margin: 0;
    background: var(--paper);
    color: var(--ink);
    font: 400 var(--fs-body) / 1.6 var(--font-ui);
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

h1,
h2,
h3 {
    margin: 0;
    font-family: var(--font-display);
    font-weight: 500;
    line-height: 1.1;
    letter-spacing: -0.015em;
    text-wrap: balance;
}

p {
    margin: 0;
    text-wrap: pretty;
}

a {
    color: var(--brand);
    text-underline-offset: 0.18em;
}

a:hover {
    color: var(--brand-hover);
}

button {
    font: inherit;
    color: inherit;
}

:focus-visible {
    outline: 2px solid var(--focus);
    outline-offset: 2px;
    border-radius: var(--r-sm);
}

.wrap {
    width: min(100% - 2 * var(--gutter), var(--wrap));
    margin-inline: auto;
}

.skip {
    position: absolute;
    left: var(--s-4);
    top: -100px;
    z-index: 20;
    padding: var(--s-2) var(--s-4);
    background: var(--ink);
    color: var(--paper);
    border-radius: var(--r-sm);
}

.skip:focus {
    top: var(--s-3);
}

/* A label stuck on slightly crooked, like one on an exercise book. */
.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: var(--s-2);
    margin-bottom: var(--s-4);
    padding: 0.2rem 0.7rem;
    border: 1.5px solid var(--edge);
    border-radius: var(--r-pill);
    background: var(--sheet);
    box-shadow: var(--hard-sm);
    color: var(--ink);
    font-size: 0.8125rem;
    font-weight: 700;
    letter-spacing: 0.01em;
    transform: rotate(-1.5deg);
}

.eyebrow::before {
    content: "";
    width: 0.5rem;
    height: 0.5rem;
    border-radius: 50%;
    background: var(--brand);
}

.lede,
.section__lede {
    color: var(--ink-2);
    font-size: var(--fs-lede);
    line-height: 1.55;
}

.fine {
    color: var(--ink-3);
    font-size: var(--fs-small);
}

/* The one highlighter stroke (DESIGN.md §0.8). */
.hl {
    background: linear-gradient(transparent 56%, var(--highlight) 56%, var(--highlight) 94%, transparent 94%) no-repeat 0 0 /
        100% 100%;
    padding-inline: 0.06em;
    /* Drawn once, left to right, after the headline has landed. */
    animation: hl-draw 650ms 350ms var(--ease) both;
    -webkit-box-decoration-break: clone;
    box-decoration-break: clone;
}

@keyframes hl-draw {
    from {
        background-size: 0% 100%;
    }
}

/* --- Buttons and links --------------------------------------------------- */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--s-2);
    min-height: 48px;
    padding: 0 var(--s-5);
    border: 1.5px solid var(--edge);
    border-radius: var(--r-pill);
    box-shadow: var(--hard-sm);
    font-weight: 700;
    font-size: 1rem;
    line-height: 1;
    text-decoration: none;
    cursor: pointer;
    transition: background-color var(--dur-fast) var(--ease), box-shadow var(--dur-fast) var(--ease),
        transform var(--dur-fast) var(--ease);
}

/* Lifts towards you on hover and presses flat into the page on click. */
.btn:hover {
    transform: translate(-1px, -1px);
    box-shadow: 4px 4px 0 var(--hard);
}

.btn:active {
    transform: translate(2px, 2px);
    box-shadow: 1px 1px 0 var(--hard);
}

.btn--primary {
    background: var(--brand);
    color: var(--on-brand);
}

.btn--primary:hover {
    background: var(--brand-hover);
    color: var(--on-brand);
}

.btn--ghost {
    color: var(--ink);
    background: var(--sheet);
}

.btn--ghost:hover {
    color: var(--ink);
}

.btn--sm {
    min-height: 40px;
    padding: 0 var(--s-4);
    font-size: 0.9375rem;
}

.btn--block {
    width: 100%;
}

.btn[aria-disabled="true"],
.btn[aria-disabled="true"]:hover {
    transform: none;
    box-shadow: none;
    cursor: default;
    opacity: 0.6;
}

.link-quiet {
    display: inline-flex;
    align-items: center;
    min-height: 44px;
    padding: 0 var(--s-2);
    color: var(--ink);
    font-weight: 500;
    text-decoration: none;
}

.link-quiet:hover {
    color: var(--brand);
    text-decoration: underline;
}

/* --- Navigation ---------------------------------------------------------- */

.nav {
    position: sticky;
    top: 0;
    z-index: 10;
    background: var(--paper);
    border-bottom: 1px solid var(--line);
}

.nav__inner {
    display: flex;
    align-items: center;
    gap: var(--s-5);
    min-height: 64px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: var(--s-2);
    color: var(--ink);
    font-family: var(--font-display);
    font-size: 1.4rem;
    font-weight: 600;
    letter-spacing: -0.01em;
    text-decoration: none;
}

.brand:hover {
    color: var(--ink);
}

.brand__mark {
    width: 28px;
    height: 28px;
    color: var(--brand);
}

.brand__tick {
    stroke: var(--tick);
}

.nav__links {
    display: flex;
    gap: var(--s-1);
    margin-left: var(--s-4);
}

.nav__links a {
    padding: var(--s-2) var(--s-3);
    border-radius: var(--r-sm);
    color: var(--ink-2);
    font-size: 0.9375rem;
    font-weight: 500;
    text-decoration: none;
}

.nav__links a:hover {
    color: var(--ink);
    background: var(--paper-sunk);
}

.nav__actions {
    display: flex;
    align-items: center;
    gap: var(--s-2);
    margin-left: auto;
}

@media (max-width: 760px) {
    .nav__links {
        display: none;
    }
}

.nav__actions a {
    white-space: nowrap;
}

/* The hero repeats "Sign in" right under the headline, so the narrowest
   phones drop it from the bar rather than wrap. */
@media (max-width: 359px) {
    .nav__actions .link-quiet {
        display: none;
    }
    .tabs [role="tab"] {
        padding: 0 0.4rem;
    }
}

/* --- Hero ---------------------------------------------------------------- */

.hero {
    position: relative;
    padding: var(--s-8) 0 var(--s-8);
    background-image: repeating-linear-gradient(
        to bottom,
        transparent 0,
        transparent calc(var(--rule-gap) * 1.5 - 1px),
        color-mix(in srgb, var(--rule) 55%, transparent) calc(var(--rule-gap) * 1.5 - 1px),
        color-mix(in srgb, var(--rule) 55%, transparent) calc(var(--rule-gap) * 1.5)
    );
    overflow: hidden;
}

/* The margin line runs the full height of the hero, just left of the text. */
.hero::before {
    content: "";
    position: absolute;
    top: 0;
    bottom: 0;
    left: max(calc(var(--gutter) / 2), calc((100% - var(--wrap)) / 2 - 1.75rem));
    border-left: 2px solid var(--margin);
}

.hero > .wrap {
    position: relative;
}

.hero__grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: var(--s-7);
    align-items: start;
}

@media (min-width: 980px) {
    .hero {
        padding-top: var(--s-8);
    }
    .hero__grid {
        grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
        gap: var(--s-8);
    }
}

.hero__title {
    font-size: var(--fs-hero);
    font-weight: 600;
    line-height: 0.98;
    letter-spacing: -0.035em;
    margin-bottom: var(--s-5);
}

.hero__copy .lede {
    max-width: 36rem;
}

.hero__ctas {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--s-3);
    margin: var(--s-6) 0 var(--s-4);
}

@media (max-width: 480px) {
    .hero__copy .hero__ctas .btn {
        flex: 1 1 100%;
    }
}

/* --- The sheet: an exercise-book page ------------------------------------ */

.sheet {
    position: relative;
    background: var(--sheet);
    border: 1.5px solid var(--edge);
    border-radius: var(--r-lg);
    box-shadow: var(--hard-lg);
    overflow: hidden;
}

.sheet__bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--s-3);
    padding: var(--s-3) var(--s-5);
    border-bottom: 1px solid var(--line);
    font-size: var(--fs-small);
}

.sheet__crumb {
    color: var(--ink-2);
    font-weight: 500;
}

/* Ruled paper with a red margin line on the left. */
.sheet__page {
    position: relative;
    padding: var(--s-5) var(--s-5) var(--s-6) calc(var(--s-5) + 2.25rem);
    background-image: repeating-linear-gradient(
        to bottom,
        transparent 0,
        transparent calc(var(--rule-gap) - 1px),
        var(--rule) calc(var(--rule-gap) - 1px),
        var(--rule) var(--rule-gap)
    );
    background-position: 0 var(--s-5);
}

.sheet__page::before {
    content: "";
    position: absolute;
    top: 0;
    bottom: 0;
    left: 2.25rem;
    border-left: 2px solid var(--margin);
}

@media (max-width: 480px) {
    .sheet__bar {
        padding-inline: var(--s-4);
    }
    .sheet__page {
        padding: var(--s-4) var(--s-4) var(--s-5) calc(var(--s-4) + 1.25rem);
        background-position: 0 var(--s-4);
    }
    .sheet__page::before {
        left: 1.1rem;
    }
}

.demo-tag {
    flex: none;
    padding: 2px var(--s-2);
    border: 1.5px solid var(--band-ink);
    border-radius: var(--r-sm);
    background: var(--band-yellow);
    color: var(--band-ink);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.01em;
    white-space: nowrap;
}

.demo-note {
    margin-top: var(--s-3);
    color: var(--ink-3);
    font-size: var(--fs-small);
    max-width: 46rem;
}

.margin-note {
    color: var(--pen);
    font-family: var(--font-hand);
    font-size: var(--fs-hand);
    font-weight: 600;
    line-height: 1.2;
}

/* --- Hero demo: the mistake loop ----------------------------------------- */

.loop__kicker {
    color: var(--ink-3);
    font-size: var(--fs-small);
    font-weight: 600;
    line-height: var(--rule-gap);
}

.loop__q {
    margin-bottom: var(--rule-gap);
    font-family: var(--font-display);
    font-size: clamp(1.25rem, 1.1rem + 0.6vw, 1.5rem);
    line-height: var(--rule-gap);
}

.options {
    display: grid;
    gap: var(--s-2);
    margin: 0;
    padding: 0;
    list-style: none;
    counter-reset: opt;
}

.opt {
    position: relative;
    display: flex;
    align-items: flex-start;
    gap: var(--s-3);
    width: 100%;
    min-height: 48px;
    padding: var(--s-3) var(--s-4);
    background: var(--sheet);
    border: 1px solid var(--line-strong);
    border-radius: var(--r-md);
    text-align: left;
    line-height: 1.4;
    cursor: pointer;
    transition: border-color var(--dur-fast) var(--ease), background-color var(--dur-fast) var(--ease);
}

.opt::before {
    content: attr(data-key);
    flex: none;
    display: grid;
    place-items: center;
    width: 1.6rem;
    height: 1.6rem;
    border: 1px solid var(--line-strong);
    border-radius: var(--r-sm);
    color: var(--ink-2);
    font-size: 0.8125rem;
    font-weight: 600;
}

.opt:hover:not([aria-disabled="true"]) {
    border-color: var(--brand);
    background: var(--brand-soft);
}

.opt[aria-disabled="true"] {
    cursor: default;
}

.opt.is-right {
    border-color: var(--ok);
    background: var(--ok-soft);
}

.opt.is-right::before {
    content: "✓";
    border-color: var(--ok);
    background: var(--ok);
    color: var(--sheet);
}

.opt.is-wrong {
    border-color: var(--pen);
    background: var(--pen-soft);
}

.opt.is-wrong span {
    text-decoration: line-through;
    text-decoration-color: var(--pen);
    text-decoration-thickness: 2px;
}

.opt.is-wrong::before {
    content: "✗";
    border-color: var(--pen);
    color: var(--pen);
}

/* A red-pen ring drawn round a wrong answer. landing.js sizes the path to
   the button so the stroke isn't stretched. */
.ring {
    position: absolute;
    top: -10px;
    left: -12px;
    overflow: visible;
    pointer-events: none;
}

.ring path {
    fill: none;
    stroke: var(--pen);
    stroke-width: 2.5;
    stroke-linecap: round;
    stroke-dasharray: 1;
    stroke-dashoffset: 1;
    animation: pen-draw 520ms 80ms var(--ease) forwards;
}

@keyframes pen-draw {
    to {
        stroke-dashoffset: 0;
    }
}

/* "go on, get one wrong": a pencilled nudge that leaves once you answer. */
.nudge {
    display: flex;
    align-items: flex-end;
    justify-content: flex-end;
    gap: var(--s-1);
    margin: 0 var(--s-5) var(--s-2) 0;
    color: var(--pen);
    font-family: var(--font-hand);
    font-size: 1.6rem;
    font-weight: 600;
    line-height: 1;
    transform: rotate(-3deg);
    transition: opacity var(--dur) var(--ease);
}

.nudge svg {
    width: 44px;
    height: 40px;
    margin-bottom: -18px;
}

.nudge path {
    fill: none;
    stroke: currentColor;
    stroke-width: 2.2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.hero__demo:has(.loop:not([data-state="ask"])) .nudge {
    opacity: 0;
}

.opt.is-dim {
    opacity: 0.55;
}

.loop__out:empty {
    display: none;
}

.loop__out {
    margin-top: var(--s-5);
    display: grid;
    gap: var(--s-4);
}

.reveal {
    animation: rise var(--dur-slow) var(--ease) both;
}

.reveal--late {
    animation-delay: 180ms;
}

@keyframes rise {
    from {
        opacity: 0;
        transform: translateY(6px);
    }
    to {
        opacity: 1;
        transform: none;
    }
}

.note-card {
    padding: var(--s-4);
    border-radius: var(--r-md);
    background: var(--paper-sunk);
    border: 1px solid var(--line);
}

.note-card__label {
    margin-bottom: var(--s-1);
    color: var(--ink-3);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

.note-card--pen {
    background: var(--pen-soft);
    border-color: transparent;
}

.note-card--pen .note-card__label {
    color: var(--pen);
}

.actions {
    display: flex;
    flex-wrap: wrap;
    gap: var(--s-2);
    align-items: center;
}

.actions .fine {
    flex: 1 1 14rem;
}

.btn-text {
    min-height: 44px;
    padding: 0 var(--s-2);
    background: none;
    border: 0;
    color: var(--brand);
    font-weight: 600;
    text-decoration: underline;
    text-underline-offset: 0.18em;
    cursor: pointer;
}

/* The "Fixed" moment: a dated trail, like the app's check-back screen. */
.trail {
    display: grid;
    gap: var(--s-1);
    margin: 0;
    padding: 0;
    list-style: none;
}

.trail li {
    display: grid;
    grid-template-columns: 5.5rem 1fr;
    gap: var(--s-3);
    align-items: baseline;
}

.trail__when {
    color: var(--pen);
    font-family: var(--font-hand);
    font-size: var(--fs-hand);
    line-height: 1;
}

.stamp {
    display: inline-flex;
    align-items: center;
    gap: var(--s-2);
    color: var(--ok);
    font-family: var(--font-display);
    font-size: 1.6rem;
    font-weight: 600;
}

.stamp svg {
    width: 1.6rem;
    height: 1.6rem;
}

/* --- Sections ------------------------------------------------------------ */

.section {
    padding: var(--s-9) 0;
    border-top: 1px solid var(--line);
    scroll-margin-top: 64px; /* clear the sticky nav when jumped to */
}

@media (max-width: 640px) {
    .section {
        padding: var(--s-8) 0;
    }
    .hero {
        padding: var(--s-6) 0 var(--s-8);
    }
}

.section__head {
    max-width: 44rem;
    margin-bottom: var(--s-7);
}

.section__head h2,
.plans__free h2,
.faq__title {
    font-weight: 600;
    letter-spacing: -0.03em;
    line-height: 1.02;
}

.section__head h2 {
    font-size: var(--fs-h2);
    margin-bottom: var(--s-4);
}

.section--sunk {
    background: var(--paper-sunk);
}

/* --- Capture to lesson --------------------------------------------------- */

.studio {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: var(--s-6);
    align-items: start;
}

@media (min-width: 980px) {
    .studio {
        grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
        gap: var(--s-7);
    }
}

.capture__label {
    margin-bottom: var(--s-3);
    font-weight: 600;
}

.chips {
    display: flex;
    flex-wrap: wrap;
    gap: var(--s-2);
    margin-bottom: var(--s-4);
}

.chip {
    min-height: 44px;
    padding: 0 var(--s-4);
    border: 1px solid var(--line-strong);
    border-radius: var(--r-pill);
    background: var(--sheet);
    color: var(--ink-2);
    font-size: 0.9375rem;
    font-weight: 500;
    cursor: pointer;
    transition: border-color var(--dur-fast) var(--ease), background-color var(--dur-fast) var(--ease);
}

.chip:hover {
    border-color: var(--ink-3);
}

.chip[aria-checked="true"] {
    border-color: var(--edge);
    box-shadow: var(--hard-sm);
    background: var(--brand-soft);
    color: var(--ink);
}

/* The capture box from Home: a notebook page in the serif. */
.capture__page {
    position: relative;
    min-height: calc(var(--rule-gap) * 6 + 1rem);
    padding: 0.55rem var(--s-4) var(--s-3) 2.75rem;
    background: var(--sheet);
    border: 1.5px solid var(--edge);
    border-radius: var(--r-lg);
    box-shadow: var(--hard-sm);
    background-image: repeating-linear-gradient(
        to bottom,
        transparent 0,
        transparent calc(var(--rule-gap) - 1px),
        var(--rule) calc(var(--rule-gap) - 1px),
        var(--rule) var(--rule-gap)
    );
}

.capture__page::before {
    content: "";
    position: absolute;
    top: 0;
    bottom: 0;
    left: 2rem;
    border-left: 2px solid var(--margin);
}

.capture__text {
    font-family: var(--font-display);
    font-size: 1.1rem;
    line-height: var(--rule-gap);
    white-space: pre-line;
}

.capture__foot {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--s-3) var(--s-4);
    margin-top: var(--s-4);
}

.steps {
    display: grid;
    gap: var(--s-1);
    margin: var(--s-5) 0 0;
    padding: 0;
    list-style: none;
    color: var(--ink-3);
    font-size: var(--fs-small);
}

.steps li {
    display: flex;
    align-items: center;
    gap: var(--s-2);
}

.steps li::before {
    content: "";
    flex: none;
    width: 0.9rem;
    height: 0.9rem;
    border: 1.5px solid var(--line-strong);
    border-radius: 50%;
}

.steps li.is-active {
    color: var(--ink);
}

.steps li.is-active::before {
    border-color: var(--brand);
    border-right-color: transparent;
    animation: spin 800ms linear infinite;
}

.steps li.is-done {
    color: var(--ink-2);
}

.steps li.is-done::before {
    border-color: var(--ok);
    background: var(--ok);
    box-shadow: inset 0 0 0 2px var(--sheet);
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.lesson {
    min-height: 30rem;
    scroll-margin-top: 80px;
}

.lesson__empty {
    display: grid;
    place-content: center;
    gap: var(--s-2);
    min-height: 30rem;
    padding: var(--s-6);
    text-align: center;
    background-image: repeating-linear-gradient(
        to bottom,
        transparent 0,
        transparent calc(var(--rule-gap) - 1px),
        var(--rule) calc(var(--rule-gap) - 1px),
        var(--rule) var(--rule-gap)
    );
}

.lesson__ghost {
    color: var(--ink-3);
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-style: italic;
}

.lesson__body.is-entering {
    animation: rise var(--dur-slow) var(--ease) both;
}

.lesson__title {
    padding: var(--s-4) var(--s-5) 0;
    font-size: clamp(1.5rem, 1.25rem + 1vw, 2rem);
}

.tabs {
    display: flex;
    gap: var(--s-1);
    margin-top: var(--s-3);
    padding: 0 var(--s-4);
    border-bottom: 1px solid var(--line);
    overflow-x: auto;
    scrollbar-width: none;
}

.tabs::-webkit-scrollbar {
    display: none;
}

.tabs [role="tab"] {
    position: relative;
    flex: none;
    display: inline-flex;
    align-items: center;
    gap: var(--s-1);
    min-height: 44px;
    padding: 0 var(--s-3);
    background: none;
    border: 0;
    color: var(--ink-3);
    font-weight: 600;
    font-size: 0.9375rem;
    cursor: pointer;
}

.tabs [role="tab"]::after {
    content: "";
    position: absolute;
    left: var(--s-2);
    right: var(--s-2);
    bottom: -1px;
    height: 2px;
    border-radius: 2px;
    background: var(--brand);
    transform: scaleX(0);
    transition: transform var(--dur) var(--ease);
}

.tabs [role="tab"]:hover {
    color: var(--ink);
}

.tabs [role="tab"][aria-selected="true"] {
    color: var(--ink);
}

.tabs [role="tab"][aria-selected="true"]::after {
    transform: scaleX(1);
}

.count:empty {
    display: none;
}

.count {
    min-width: 1.35rem;
    padding: 0 0.35rem;
    border-radius: var(--r-pill);
    background: var(--brand-soft);
    color: var(--brand);
    font-size: 0.75rem;
    line-height: 1.35rem;
    text-align: center;
}

.count--pen {
    background: var(--pen-soft);
    color: var(--pen);
}

.panel {
    padding: var(--s-5);
    min-height: 22rem;
}

.panel:focus-visible {
    outline-offset: -4px;
}

@media (max-width: 480px) {
    .panel {
        padding: var(--s-4);
    }
    .lesson__title {
        padding-inline: var(--s-4);
    }
    .tabs {
        gap: 0;
        padding-inline: var(--s-1);
    }
    .tabs [role="tab"] {
        padding: 0 var(--s-2);
        font-size: 0.875rem;
    }
}

/* Notes: the reading page */
.notes h4 {
    margin: var(--s-4) 0 var(--s-1);
    font-family: var(--font-display);
    font-size: 1.2rem;
    font-weight: 600;
}

.notes h4:first-child {
    margin-top: 0;
}

.notes p,
.notes li {
    color: var(--ink-2);
    font-family: var(--font-display);
    font-size: 1.075rem;
    line-height: 1.6;
}

.notes ul {
    margin: var(--s-1) 0 0;
    padding-left: 1.2rem;
}

.notes strong {
    color: var(--ink);
}

/* Cards: one card that turns over */
.card-stage {
    display: grid;
    gap: var(--s-4);
}

.card-meta {
    display: flex;
    justify-content: space-between;
    color: var(--ink-3);
    font-size: var(--fs-small);
}

.flash {
    perspective: 1200px;
}

.flash__btn {
    position: relative;
    display: block;
    width: 100%;
    min-height: 13rem;
    padding: 0;
    background: none;
    border: 0;
    cursor: pointer;
    transform-style: preserve-3d;
    transition: transform var(--dur-slow) var(--ease);
}

.flash__btn[aria-pressed="true"] {
    transform: rotateY(180deg);
}

.flash__face {
    position: absolute;
    inset: 0;
    display: grid;
    place-content: center;
    gap: var(--s-2);
    padding: var(--s-5);
    border: 1px solid var(--line-strong);
    border-radius: var(--r-lg);
    background: var(--sheet);
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    text-align: center;
}

.flash__face--back {
    transform: rotateY(180deg);
    background: var(--paper-sunk);
}

.flash__text {
    font-family: var(--font-display);
    font-size: 1.3rem;
    line-height: 1.35;
}

.flash__hint {
    color: var(--ink-3);
    font-size: var(--fs-small);
}

.grade {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--s-2);
}

.grade .btn {
    border-radius: var(--r-md);
}

.btn--again {
    background: var(--pen-soft);
    color: var(--pen);
}

.btn--again:hover {
    border-color: var(--pen);
}

.btn--good {
    background: var(--ok-soft);
    color: var(--ok);
}

.btn--good:hover {
    border-color: var(--ok);
}

/* Tutor */
.starters {
    display: flex;
    flex-wrap: wrap;
    gap: var(--s-2);
    margin: var(--s-3) 0 var(--s-4);
}

.chat {
    display: grid;
    gap: var(--s-3);
}

.bubble {
    max-width: 92%;
    padding: var(--s-3) var(--s-4);
    border-radius: var(--r-lg);
    line-height: 1.55;
}

.bubble--me {
    justify-self: end;
    background: var(--brand-soft);
    border-bottom-right-radius: var(--r-sm);
}

.bubble--tutor {
    justify-self: start;
    background: var(--paper-sunk);
    border: 1px solid var(--line);
    border-bottom-left-radius: var(--r-sm);
    font-family: var(--font-display);
    font-size: 1.06rem;
}

.bubble--tutor .margin-note {
    display: block;
    margin-top: var(--s-2);
    font-size: 1.2rem;
}

/* Mistakes list: ruled rows with a red-pen spine */
.mistakes {
    display: grid;
    margin: 0;
    padding: 0;
    list-style: none;
}

.mistakes li {
    padding: var(--s-3) 0 var(--s-3) var(--s-4);
    border-bottom: 1px solid var(--rule);
    border-left: 3px solid var(--pen);
}

.mistakes h4 {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 600;
}

.empty {
    display: grid;
    gap: var(--s-2);
    padding: var(--s-6) var(--s-4);
    text-align: center;
}

.empty__title {
    font-family: var(--font-display);
    font-size: 1.25rem;
}

/* --- The loop timeline --------------------------------------------------- */

/* The exercise book's cover: the one dark band on the page. Tokens are
   re-pointed here so everything inside reads on teal in either theme. */
.section--cover {
    --ink: var(--cover-ink);
    --ink-2: var(--cover-ink-2);
    --pen: #ffa597;
    --ok: #9fe8c1;
    --line-strong: rgba(246, 243, 234, 0.35);
    --paper: var(--cover);
    --sheet: var(--cover-mark);
    --edge: var(--band-ink);
    --hard: #06231f;
    background: var(--cover);
    color: var(--ink);
    border-top: 0;
}

.section--cover .eyebrow {
    color: var(--band-ink);
}

.section--cover .eyebrow::before {
    background: var(--band-ink);
}

.section--cover .timeline__stop::before {
    border-color: var(--cover-mark);
}

.section--cover .timeline__when {
    color: var(--cover-mark);
}

/* A red-pen ring round one word in a heading, drawn when it scrolls in. */
.circled {
    position: relative;
    display: inline-block;
    white-space: nowrap;
}

.circled svg {
    position: absolute;
    left: -12%;
    top: -14%;
    width: 124%;
    height: 132%;
    overflow: visible;
    pointer-events: none;
}

.circled path {
    fill: none;
    stroke: var(--cover-mark);
    stroke-width: 3;
    stroke-linecap: round;
    stroke-dasharray: 1;
    stroke-dashoffset: 0;
}

.circled.is-pending path {
    stroke-dashoffset: 1;
}

.circled.is-drawn path {
    stroke-dashoffset: 0;
    transition: stroke-dashoffset 700ms 150ms var(--ease);
}

.timeline {
    position: relative;
    display: grid;
    gap: var(--s-6);
    margin: 0;
    padding: 0;
    list-style: none;
}

.timeline__stop {
    position: relative;
    padding-left: 2.25rem;
}

/* A line joins the stops: down the left on narrow screens. */
.timeline__stop::before {
    content: "";
    position: absolute;
    left: 0.45rem;
    top: 0.35rem;
    width: 0.8rem;
    height: 0.8rem;
    border: 2px solid var(--pen);
    border-radius: 50%;
    background: var(--paper);
    z-index: 1;
}

.timeline__stop::after {
    content: "";
    position: absolute;
    left: calc(0.85rem - 1px);
    top: 1.2rem;
    bottom: calc(-1 * var(--s-6) - 0.35rem);
    border-left: 2px dashed var(--line-strong);
}

.timeline__stop:last-child::after {
    display: none;
}

.timeline__stop--done::before {
    border-color: var(--ok);
    background: var(--ok);
}

.timeline__when {
    display: block;
    margin-bottom: var(--s-1);
    color: var(--pen);
    font-family: var(--font-hand);
    font-size: var(--fs-hand);
    line-height: 1.1;
}

.timeline__stop--done .timeline__when {
    color: var(--ok);
}

.timeline h3 {
    margin-bottom: var(--s-2);
    font-size: var(--fs-h3);
}

.timeline p {
    color: var(--ink-2);
}

.timeline .margin-note {
    margin-top: var(--s-2);
}

@media (min-width: 900px) {
    .timeline {
        grid-template-columns: repeat(4, minmax(0, 1fr));
        gap: var(--s-6);
    }
    .timeline__stop {
        padding: 2.25rem 0 0;
    }
    .timeline__stop::before {
        left: 0;
        top: 0;
    }
    /* ...and across the top on wide ones. */
    .timeline__stop::after {
        left: 1.1rem;
        right: calc(-1 * var(--s-6));
        top: calc(0.4rem - 1px);
        bottom: auto;
        border-left: 0;
        border-top: 2px dashed var(--line-strong);
    }
}

/* --- The rest of the week: ruled rows with spines ------------------------ */

.more {
    display: grid;
    gap: var(--s-6);
}

@media (min-width: 980px) {
    .more {
        grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
        gap: var(--s-8);
        align-items: start;
    }
    .section__head--side {
        position: sticky;
        top: 6rem;
        margin-bottom: 0;
    }
}

.rows {
    margin: 0;
    padding: 0;
    list-style: none;
    background: var(--sheet);
    border: 1px solid var(--line);
    border-radius: var(--r-lg);
    overflow: hidden;
}

.row {
    position: relative;
    padding: var(--s-4) var(--s-5) var(--s-4) calc(var(--s-5) + 3px);
    border-bottom: 1px solid var(--rule);
}

.row:last-child {
    border-bottom: 0;
}

.row::before {
    content: "";
    position: absolute;
    left: 0;
    top: var(--s-3);
    bottom: var(--s-3);
    width: 3px;
    border-radius: 0 3px 3px 0;
    background: var(--spine, var(--spine-1));
}

.row:nth-child(2) { --spine: var(--spine-2); }
.row:nth-child(3) { --spine: var(--spine-3); }
.row:nth-child(4) { --spine: var(--spine-4); }
.row:nth-child(5) { --spine: var(--spine-5); }
.row:nth-child(6) { --spine: var(--spine-6); }
.row:nth-child(7) { --spine: var(--spine-7); }

.row h3 {
    display: flex;
    align-items: center;
    gap: var(--s-2);
    margin-bottom: var(--s-1);
    font-size: 1.2rem;
}

.row p {
    color: var(--ink-2);
}

.tag {
    padding: 1px var(--s-2);
    border-radius: var(--r-sm);
    background: var(--brand-soft);
    color: var(--brand);
    font-family: var(--font-ui);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.02em;
}

/* --- Plans and answers --------------------------------------------------- */

.plans {
    display: grid;
    gap: var(--s-7);
}

@media (min-width: 980px) {
    .plans {
        grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
        gap: var(--s-8);
    }
}

.plans__free h2 {
    font-size: var(--fs-h2);
    margin-bottom: var(--s-4);
}

.allowance {
    margin-top: var(--s-6);
    padding: var(--s-5);
    display: grid;
    gap: var(--s-4);
}

.allowance__head {
    font-weight: 600;
}

.allowance__list {
    margin: 0;
}

.allowance__list div {
    display: flex;
    justify-content: space-between;
    gap: var(--s-4);
    padding: var(--s-2) 0;
    border-bottom: 1px solid var(--rule);
}

.allowance__list dt {
    color: var(--ink-2);
}

.allowance__list dd {
    margin: 0;
    font-family: var(--font-display);
    font-size: 1.2rem;
    font-weight: 600;
    font-variant-numeric: tabular-nums;
}

.plans__paid {
    margin-top: var(--s-5);
    color: var(--ink-2);
}

.faq__title {
    font-size: var(--fs-h2);
    margin-bottom: var(--s-5);
}

.faq details {
    border-bottom: 1px solid var(--line-strong);
}

.faq summary {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--s-4);
    min-height: 56px;
    padding: var(--s-3) 0;
    font-family: var(--font-display);
    font-size: 1.2rem;
    font-weight: 500;
    cursor: pointer;
    list-style: none;
}

.faq summary::-webkit-details-marker {
    display: none;
}

.faq summary::after {
    content: "+";
    flex: none;
    color: var(--brand);
    font-family: var(--font-ui);
    font-size: 1.4rem;
    line-height: 1;
    transition: transform var(--dur) var(--ease);
}

.faq details[open] summary::after {
    transform: rotate(45deg);
}

.faq details p {
    padding-bottom: var(--s-4);
    color: var(--ink-2);
    max-width: 40rem;
}

/* --- Closing ------------------------------------------------------------- */

/* The last page is highlighter yellow. Fixed ink and teal so it reads the
   same in light and dark. */
.closing {
    --ink: var(--band-ink);
    --ink-2: #3a3d33;
    --edge: var(--band-ink);
    --hard: var(--band-ink);
    --brand: #0e6b5f;
    --brand-hover: #0a564c;
    --on-brand: #ffffff;
    --sheet: #fffdf5;
    padding: var(--s-9) 0;
    background: var(--band-yellow);
    color: var(--ink);
    text-align: center;
}

.closing__inner {
    display: grid;
    justify-items: center;
    gap: var(--s-3);
}

.closing h2 {
    font-size: clamp(2.6rem, 1.6rem + 4vw, 5rem);
    font-weight: 600;
    letter-spacing: -0.035em;
}

.closing p {
    color: var(--ink-2);
    font-size: var(--fs-lede);
}

.closing .hero__ctas {
    justify-content: center;
    margin-bottom: 0;
}

/* --- Footer -------------------------------------------------------------- */

.footer {
    padding: var(--s-7) 0 var(--s-5);
    border-top: 1px solid var(--line);
    background: var(--paper-sunk);
}

.footer__grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--s-6) var(--s-5);
}

.footer__brand {
    grid-column: 1 / -1;
    display: grid;
    align-content: start;
    justify-items: start;
    gap: var(--s-2);
    max-width: 20rem;
}

@media (min-width: 860px) {
    .footer__grid {
        grid-template-columns: 2fr repeat(4, minmax(0, 1fr));
    }
    .footer__brand {
        grid-column: auto;
    }
}

.footer__col {
    display: grid;
    align-content: start;
    gap: var(--s-1);
}

.footer__col h2 {
    margin-bottom: var(--s-1);
    font-family: var(--font-ui);
    font-size: var(--fs-small);
    font-weight: 700;
    letter-spacing: 0.02em;
}

.footer__col a {
    display: inline-flex;
    align-items: center;
    min-height: 36px;
    color: var(--ink-2);
    text-decoration: none;
}

.footer__col a:hover {
    color: var(--ink);
    text-decoration: underline;
}

.footer__bottom {
    margin-top: var(--s-6);
    padding-top: var(--s-4);
    border-top: 1px solid var(--line);
    color: var(--ink-3);
    font-size: var(--fs-small);
}

/* --- Reduced motion ------------------------------------------------------ */

@media (prefers-reduced-motion: reduce) {
    .hl,
    .ring path {
        animation: none;
        stroke-dashoffset: 0;
    }
    html {
        scroll-behavior: auto;
    }
    *,
    *::before,
    *::after {
        animation-duration: 1ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 1ms !important;
    }
    /* A card that flips in place becomes a card that swaps faces. */
    .flash__btn,
    .flash__btn[aria-pressed="true"] {
        transform: none;
    }
    .flash__face--back {
        transform: none;
        visibility: hidden;
    }
    .flash__btn[aria-pressed="true"] .flash__face--front {
        visibility: hidden;
    }
    .flash__btn[aria-pressed="true"] .flash__face--back {
        visibility: visible;
    }
}