.prop-page {
    --prop-blue: #1e3a5f;
    --prop-teal: #168a96;
    --prop-light-teal: #dff7f4;
    --prop-yellow: #f4b942;
    --prop-orange: #ef8354;
    --prop-green: #3da66b;
    --prop-red: #c94b55;
    --prop-ink: #19324d;
    --prop-muted: #60758b;
    --prop-border: #d9e6ec;
}

.prop-page h1,
.prop-page h2,
.prop-page p {
    color: var(--prop-ink);
}

.prop-progress {
    margin: 1.25rem 0 2rem;
    padding: 1rem 1.25rem;
    background: #fff;
    border: 1px solid var(--prop-border);
    border-radius: 18px;
    box-shadow: 0 10px 30px rgba(30, 58, 95, 0.07);
}

.prop-progress__text {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    margin-bottom: .7rem;
    font-size: .92rem;
    color: var(--prop-muted);
}

.prop-progress__text strong { color: var(--prop-blue); }
.prop-progress__track { height: 10px; overflow: hidden; background: #e9f0f3; border-radius: 999px; }
.prop-progress__fill { display: block; height: 100%; background: linear-gradient(90deg, var(--prop-teal), var(--prop-yellow)); border-radius: inherit; transition: width .4s ease; }
.prop-progress__fill--1 { width: 8.333%; }
.prop-progress__fill--2 { width: 16.666%; }
.prop-progress__fill--3 { width: 25%; }
.prop-progress__fill--4 { width: 33.333%; }
.prop-progress__fill--5 { width: 41.666%; }
.prop-progress__fill--6 { width: 50%; }
.prop-progress__fill--7 { width: 58.333%; }
.prop-progress__fill--8 { width: 66.666%; }
.prop-progress__fill--9 { width: 75%; }
.prop-progress__fill--10 { width: 83.333%; }
.prop-progress__fill--11 { width: 91.666%; }
.prop-progress__fill--12 { width: 100%; }

.prop-hero,
.prop-percent-visual {
    display: grid;
    grid-template-columns: minmax(0, 1.1fr) minmax(300px, .9fr);
    align-items: center;
    gap: clamp(2rem, 5vw, 4rem);
    padding: clamp(2rem, 5vw, 4rem);
    background: linear-gradient(135deg, #f0fcfb, #fff9e9);
    border: 1px solid #d9eeeb;
    border-radius: 30px;
}

.prop-heading { max-width: 850px; margin: 2.5rem auto; text-align: center; }
.prop-heading h1,
.prop-hero h1 { margin: .25rem 0 1rem; font-size: clamp(2rem, 5vw, 3.35rem); line-height: 1.08; color: var(--prop-blue); }
.prop-lead { font-size: clamp(1.08rem, 2vw, 1.3rem); line-height: 1.65; }

.prop-callout,
.prop-warning {
    display: flex;
    align-items: flex-start;
    gap: .9rem;
    margin-top: 1.5rem;
    padding: 1rem 1.2rem;
    background: #fff;
    border-left: 5px solid var(--prop-yellow);
    border-radius: 12px;
}

.prop-callout span,
.prop-warning span { font-size: 1.6rem; }
.prop-callout p,
.prop-warning p { margin: 0; }
.prop-warning { margin: 1.5rem 0 2rem; background: #fff8e8; }

.prop-visual--recipe { display: flex; align-items: center; justify-content: center; gap: 1rem; }
.prop-recipe-card {
    display: grid;
    gap: .65rem;
    min-width: 145px;
    padding: 1.4rem;
    background: #fff;
    border: 2px solid var(--prop-border);
    border-radius: 20px;
    text-align: center;
    box-shadow: 0 14px 30px rgba(30, 58, 95, .1);
}
.prop-recipe-card.is-result { border-color: var(--prop-teal); transform: rotate(2deg); }
.prop-recipe-card strong { font-size: 1.2rem; color: var(--prop-blue); }
.prop-arrow { flex: 0 0 auto; padding: .45rem .75rem; color: #fff; background: var(--prop-orange); border-radius: 999px; font-weight: 800; }

.prop-page .interactive-lesson { margin-top: 2.5rem; }
.prop-question-list { display: grid; gap: 1.1rem; }
.prop-question {
    padding: clamp(1.35rem, 4vw, 2.25rem);
    background: #fff;
    border: 2px solid var(--prop-border);
    border-radius: 20px;
    transition: border-color .2s ease, box-shadow .2s ease;
}
.prop-question.is-complete { border-color: #86d3a5; box-shadow: 0 10px 25px rgba(61, 166, 107, .1); }
.prop-question > p:first-child { margin-top: 0; }
.prop-question h2 { font-size: 1.2rem; }
.prop-question__number { margin: 0 0 .25rem; color: var(--prop-teal) !important; font-size: .8rem; font-weight: 800; text-transform: uppercase; letter-spacing: .08em; }

.prop-choices { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: .8rem; margin-top: 1.2rem; }
.prop-choices--small { grid-template-columns: repeat(2, minmax(160px, 260px)); }
.prop-choices button {
    min-height: 58px;
    padding: .85rem 1rem;
    color: var(--prop-blue);
    background: #f7fbfc;
    border: 2px solid #cddde4;
    border-radius: 14px;
    font: inherit;
    font-weight: 750;
    cursor: pointer;
    transition: transform .15s ease, border-color .15s ease, background .15s ease;
}
.prop-choices button:hover:not(:disabled),
.prop-choices button:focus-visible { transform: translateY(-2px); border-color: var(--prop-teal); background: #eaf8f7; }
.prop-choices button.is-wrong { border-color: var(--prop-red); background: #fff0f1; animation: prop-shake .25s linear; }
.prop-choices button.is-correct { color: #155b36; border-color: var(--prop-green); background: #e8f8ef; }
.prop-choices button:disabled { cursor: default; opacity: .75; }
.prop-choices button.is-correct:disabled { opacity: 1; }

.activity-feedback { margin-top: 1rem; padding: .9rem 1rem; border-radius: 12px; font-weight: 700; }
.activity-feedback.is-success { color: #155b36; background: #e8f8ef; border-left: 5px solid var(--prop-green); }
.activity-feedback.is-error { color: #8d2530; background: #fff0f1; border-left: 5px solid var(--prop-red); }

.prop-method-grid,
.prop-evolution-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.2rem; margin: 2rem 0; }
.prop-method-grid article,
.prop-evolution-grid article { padding: 1.8rem; }
.prop-method-grid h2,
.prop-evolution-grid h2 { margin: .5rem 0; }
.prop-icon { font-size: 2rem; }

.prop-table-card,
.prop-worked-example { padding: clamp(1.25rem, 4vw, 2.5rem); margin: 2rem 0; }
.prop-table-scroll { overflow-x: auto; }
.prop-table { width: 100%; min-width: 560px; border-collapse: separate; border-spacing: 0; color: var(--prop-ink); }
.prop-table caption { margin-bottom: 1rem; color: var(--prop-blue); font-size: 1.2rem; font-weight: 800; text-align: left; }
.prop-table th,
.prop-table td { padding: 1rem; border-right: 1px solid #cfe0e6; border-bottom: 1px solid #cfe0e6; text-align: center; }
.prop-table th { width: 25%; color: #fff; background: var(--prop-blue); text-align: left; }
.prop-table tr:first-child th { border-radius: 14px 0 0 0; }
.prop-table tr:last-child th { border-radius: 0 0 0 14px; }
.prop-table tr:first-child td { background: #effaf8; }
.prop-table tr:last-child td { background: #fff9e8; }
.prop-table .is-missing { color: var(--prop-orange); background: #fff2eb !important; font-size: 1.4rem; font-weight: 900; }
.prop-table-explanation { display: flex; align-items: center; gap: 1rem; margin-top: 1.25rem; }
.prop-table-explanation span { padding: .5rem .8rem; color: #fff; background: var(--prop-teal); border-radius: 999px; font-weight: 800; }
.prop-table-explanation p { margin: 0; }
.prop-operation { display: flex; flex-wrap: wrap; justify-content: center; align-items: center; gap: 1rem; margin-top: 1.5rem; font-size: 1.1rem; }
.prop-operation strong { padding: .7rem 1rem; color: #fff; background: var(--prop-teal); border-radius: 12px; }

.prop-input-label { display: flex; flex-wrap: wrap; align-items: center; gap: .7rem; margin-bottom: 1rem; color: var(--prop-blue); font-size: 1.08rem; font-weight: 800; }
.prop-number-input { width: 120px; padding: .7rem .85rem; color: var(--prop-blue); background: #fff; border: 2px solid #b9ced7; border-radius: 10px; font: inherit; font-size: 1.1rem; }
.prop-number-input:focus { outline: 3px solid rgba(22, 138, 150, .2); border-color: var(--prop-teal); }
.prop-number-input.is-wrong { border-color: var(--prop-red); background: #fff5f5; }
.prop-number-input.is-correct { border-color: var(--prop-green); background: #eefbf3; }

.prop-machine { display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 1rem; max-width: 750px; margin: 2rem auto; }
.prop-machine > div { display: grid; gap: .4rem; padding: 1.5rem; background: #fff; border: 2px solid var(--prop-border); border-radius: 18px; text-align: center; }
.prop-machine > div strong { color: var(--prop-blue); font-size: 2rem; }
.prop-machine .prop-machine__center { position: relative; color: #fff; background: linear-gradient(135deg, var(--prop-teal), #29a9a0); border: 0; }
.prop-machine .prop-machine__center::before,
.prop-machine .prop-machine__center::after { content: '→'; position: absolute; top: 50%; color: var(--prop-orange); font-size: 1.8rem; font-weight: 900; transform: translateY(-50%); }
.prop-machine .prop-machine__center::before { left: -1.7rem; }
.prop-machine .prop-machine__center::after { right: -1.7rem; }
.prop-machine .prop-machine__center strong { color: #fff; }

.prop-steps { display: grid; gap: 1rem; max-width: 820px; margin: 2rem auto; }
.prop-steps article { display: flex; align-items: center; gap: 1.25rem; padding: 1.3rem 1.5rem; background: #fff; border: 1px solid var(--prop-border); border-radius: 18px; }
.prop-steps article > span { display: grid; flex: 0 0 46px; width: 46px; height: 46px; place-items: center; color: #fff; background: var(--prop-teal); border-radius: 50%; font-weight: 900; }
.prop-steps h2,
.prop-steps p { margin: 0; }

.prop-cross-card { display: grid; grid-template-columns: minmax(250px, 380px) 1fr; align-items: center; gap: 3rem; padding: clamp(1.5rem, 5vw, 3rem); margin: 2rem 0; }
.prop-cross-table { position: relative; display: grid; grid-template-columns: repeat(2, 1fr); }
.prop-cross-table span { display: grid; min-height: 85px; place-items: center; background: #f1faf9; border: 2px solid #bcd9dd; font-size: 1.5rem; font-weight: 900; }
.prop-cross-table .is-missing { color: var(--prop-orange); background: #fff5e9; }
.prop-cross-line { position: absolute; top: 50%; left: 50%; width: 82%; height: 4px; background: var(--prop-orange); border-radius: 999px; transform-origin: center; }
.prop-cross-line--one { transform: translate(-50%, -50%) rotate(24deg); }
.prop-cross-line--two { transform: translate(-50%, -50%) rotate(-24deg); }
.prop-formula { display: flex; align-items: center; justify-content: center; gap: .8rem; color: var(--prop-blue); font-size: clamp(1.35rem, 3vw, 2rem); font-weight: 900; }
.prop-fraction { display: grid; text-align: center; }
.prop-fraction strong:first-child { padding: .25rem .5rem; border-bottom: 3px solid var(--prop-blue); }

.prop-hundred-grid { display: grid; grid-template-columns: repeat(10, 1fr); gap: 3px; max-width: 330px; aspect-ratio: 1; }
.prop-hundred-grid span { background: #e4ecef; border-radius: 2px; }
.prop-hundred-grid span.is-active { background: linear-gradient(135deg, var(--prop-yellow), var(--prop-orange)); }
.prop-big-percent { display: block; color: var(--prop-orange); font-size: clamp(3.5rem, 8vw, 6.5rem); line-height: 1; }
.prop-equivalence { display: inline-block; padding: .6rem .85rem; background: #fff; border-radius: 12px; font-weight: 800; }
.prop-percent-cards { display: grid; grid-template-columns: repeat(4, 1fr); gap: .8rem; margin: 1.5rem 0 2rem; }
.prop-percent-cards article { display: grid; gap: .25rem; padding: 1.2rem; background: #fff; border: 1px solid var(--prop-border); border-radius: 16px; text-align: center; }
.prop-percent-cards strong { color: var(--prop-teal); font-size: 1.45rem; }

.prop-formula-card { display: grid; justify-items: center; gap: .5rem; max-width: 700px; margin: 2rem auto; padding: 2rem; font-size: clamp(1.2rem, 3vw, 1.8rem); }
.prop-formula-card strong { color: var(--prop-teal); }
.prop-formula-card em { color: var(--prop-orange); font-size: 1.5em; font-style: normal; font-weight: 900; }
.prop-evolution-grid article > span { display: inline-block; padding: .4rem .65rem; color: #fff; border-radius: 999px; font-weight: 900; }
.prop-evolution-grid .is-reduction > span { background: var(--prop-green); }
.prop-evolution-grid .is-increase > span { background: var(--prop-orange); }
.prop-evolution-grid strong { display: block; margin-top: 1rem; color: var(--prop-blue); font-size: 1.25rem; }

.prop-problem { padding: clamp(1.5rem, 5vw, 3rem); margin: 2rem 0; border-top: 6px solid var(--prop-yellow); }
.prop-problem h2 { max-width: 800px; margin: 1rem 0; }
.prop-problem li { margin: .6rem 0; color: var(--prop-ink); }
.prop-score { display: flex; align-items: center; gap: 1rem; margin: 1.5rem 0; padding: 1.2rem 1.5rem; color: #fff; background: linear-gradient(135deg, var(--prop-blue), var(--prop-teal)); border-radius: 18px; }
.prop-score > span { font-size: 2.2rem; }
.prop-score p { margin: 0; color: #dff7f4; }
.prop-score strong { font-size: 1.2rem; }
.prop-score.is-complete { background: linear-gradient(135deg, #247a4b, var(--prop-green)); }
.prop-final-questions { margin-bottom: 1.5rem; }
.prop-correction { padding: 1.25rem 1.5rem; }
.prop-correction summary { color: var(--prop-blue); font-size: 1.1rem; font-weight: 800; cursor: pointer; }
.prop-correction details div { padding-top: .7rem; }

.prop-navigation { display: flex; justify-content: space-between; gap: 1rem; margin: 3rem 0 1rem; padding-top: 1.5rem; border-top: 1px solid var(--prop-border); }

@keyframes prop-shake {
    25% { transform: translateX(-4px); }
    75% { transform: translateX(4px); }
}

@media (max-width: 800px) {
    .prop-hero,
    .prop-percent-visual,
    .prop-cross-card { grid-template-columns: 1fr; }
    .prop-method-grid,
    .prop-evolution-grid { grid-template-columns: 1fr; }
    .prop-percent-cards { grid-template-columns: repeat(2, 1fr); }
    .prop-hundred-grid { width: 100%; margin: auto; }
}

@media (max-width: 560px) {
    .prop-progress__text { display: grid; gap: .2rem; }
    .prop-hero { padding: 1.5rem; }
    .prop-visual--recipe { flex-direction: column; }
    .prop-arrow { transform: rotate(90deg); }
    .prop-choices,
    .prop-choices--small { grid-template-columns: 1fr; }
    .prop-machine { grid-template-columns: 1fr; }
    .prop-machine .prop-machine__center::before,
    .prop-machine .prop-machine__center::after { display: none; }
    .prop-navigation { flex-direction: column-reverse; }
    .prop-navigation .btn { width: 100%; text-align: center; }
}

@media (prefers-reduced-motion: reduce) {
    .prop-page *,
    .prop-page *::before,
    .prop-page *::after { scroll-behavior: auto !important; transition: none !important; animation: none !important; }
}

.prop-page .memory-section__card h2 { color: #ffffff; }