:root {
    --mc-bg-page: #081225;
    --mc-surface: #0e1b34;
    --mc-surface-soft: #13223f;
    --mc-border: #223554;
    --mc-border-soft: #34507f;
    --mc-primary: #2f6df6;
    --mc-primary-hover: #1f5ae0;
    --mc-primary-soft: rgba(47, 109, 246, 0.14);
    --mc-text-main: #f8fbff;
    --mc-text-muted: #94a7c6;
    --mc-shadow-soft: 0 10px 25px rgba(0, 0, 0, 0.22);
    --mc-radius-md: 8px;
    --mc-radius-lg: 12px;
    --mc-radius-xl: 16px;
    --mc-input-bg: #1a2743;
    --mc-input-border: #2a3c5f;
    --mc-danger: #ef4444;
    --mc-success: #8fd19e;
    --mc-container: 1200px;
    --mc-header-height: 72px;
    --mc-font-main: "Manrope", sans-serif;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    background: var(--mc-bg-page);
    color: var(--mc-text-main);
    font-family: var(--mc-font-main);
    line-height: 1.55;
    min-height: 100vh;
}

a {
    color: inherit;
    text-decoration: none;
}

img {
    display: block;
    max-width: 100%;
}

.container {
    width: min(calc(100% - 40px), var(--mc-container));
    margin: 0 auto;
}

.section {
    padding: 55px 0 72px 0;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 22px;
    border-radius: 999px;
    border: 1px solid transparent;
    font-size: 0.97rem;
    font-weight: 700;
    font-family: var(--mc-font-main);
    transition: transform 0.2s ease, background-color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
    cursor: pointer;
    white-space: nowrap;
}

.btn:hover,
.btn:focus-visible {
    transform: translateY(-1px);
}

.btn-primary {
    background: var(--mc-primary);
    color: var(--mc-text-main);
    box-shadow: 0 8px 18px rgba(47, 109, 246, 0.18);
}

.btn-primary:hover,
.btn-primary:focus-visible {
    background: var(--mc-primary-hover);
}

.btn-secondary {
    background: transparent;
    border-color: rgba(52, 80, 127, 0.55);
    color: #dbe7ff;
}

.btn-secondary:hover,
.btn-secondary:focus-visible {
    background: rgba(47, 109, 246, 0.08);
    border-color: rgba(52, 80, 127, 0.85);
}

.section-kicker {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 7px 12px;
    border-radius: 999px;
    background: var(--mc-primary-soft);
    border: 1px solid rgba(47, 109, 246, 0.16);
    color: #cbdcff;
    font-size: 0.83rem;
    font-weight: 700;
    letter-spacing: 0.02em;
}

.formula-page {
    padding-top: 26px;
}

.formula-shell {
    display: grid;
    grid-template-columns: minmax(0, 1.1fr) minmax(320px, 0.9fr);
    gap: 28px;
    align-items: start;
}

.formula-copy h1 {
    margin: 18px 0 18px;
    font-size: clamp(2.2rem, 4vw, 3.8rem);
    line-height: 0.98;
    letter-spacing: -0.04em;
    max-width: 13ch;
}

.formula-lead,
.formula-muted,
.section-heading p,
.formula-card p,
.standard-intro-card p,
.density-card p,
.standard-list li strong {
    color: var(--mc-text-muted);
}

.formula-lead {
    max-width: 62ch;
    font-size: 1.06rem;
    margin: 0 0 14px;
}

.formula-muted {
    max-width: 64ch;
    margin: 0;
}

.formula-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    margin-top: 28px;
}

.formula-links {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 22px;
}

.formula-links a {
    padding: 10px 14px;
    border-radius: 999px;
    background: rgba(14, 27, 52, 0.86);
    border: 1px solid rgba(52, 80, 127, 0.34);
    color: #dbe7ff;
    font-size: 0.92rem;
    transition: border-color 0.2s ease, transform 0.2s ease, background-color 0.2s ease;
}

.formula-links a:hover,
.formula-links a:focus-visible {
    transform: translateY(-1px);
    border-color: rgba(52, 80, 127, 0.65);
    background: rgba(19, 34, 63, 0.95);
}

.formula-note-card,
.formula-card,
.standard-intro-card,
.standard-card,
.density-card,
.cta-panel {
    border-radius: var(--mc-radius-xl);
    background: rgba(14, 27, 52, 0.86);
    border: 1px solid rgba(52, 80, 127, 0.34);
    box-shadow: var(--mc-shadow-soft);
}

.formula-note-card {
    display: flex;
    gap: 18px;
    align-items: flex-start;
    padding: 22px;
}

.formula-note-card h2,
.formula-card h3,
.density-card h3,
.cta-panel h2 {
    margin: 0 0 8px;
}

.formula-note-card p,
.cta-panel p {
    margin: 0 0 10px;
    color: var(--mc-text-muted);
}

.formula-note-card p:last-child,
.cta-panel p:last-child {
    margin-bottom: 0;
}

.formula-note-icon {
    width: 52px;
    height: 52px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    background: var(--mc-primary-soft);
    border: 1px solid var(--mc-border-soft);
    color: var(--mc-primary);
    flex-shrink: 0;
}

.formula-note-icon .material-symbols-outlined {
    font-size: 28px;
}

.formula-small {
    font-size: 0.94rem;
}

.section-heading {
    max-width: 72ch;
    margin-bottom: 24px;
}

.section-heading h2 {
    margin: 16px 0 10px;
    font-size: clamp(1.7rem, 3vw, 2.5rem);
    line-height: 1.05;
    letter-spacing: -0.03em;
}

.section-heading p {
    margin: 0;
}

.formula-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
}

.formula-card {
    padding: 22px;
}

.formula-card h3 {
    font-size: 1.05rem;
}

.formula-card p {
    margin: 0 0 14px;
}

.formula-card-accent {
    border-color: rgba(47, 109, 246, 0.38);
    background: linear-gradient(180deg, rgba(14, 27, 52, 0.96) 0%, rgba(19, 34, 63, 0.92) 100%);
}

.formula-math {
    font-size: clamp(1rem, 2vw, 1.08rem);
    font-weight: 800;
    line-height: 1.5;
    color: #f3f7ff;
    letter-spacing: -0.01em;
    padding: 14px 16px;
    border-radius: 14px;
    background: rgba(8, 18, 37, 0.74);
    border: 1px solid rgba(52, 80, 127, 0.42);
    overflow-x: auto;
}

.standard-intro-card {
    padding: 22px;
    margin-bottom: 18px;
}

.standard-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
}

.standard-card {
    overflow: hidden;
}

.standard-card summary {
    list-style: none;
    cursor: pointer;
    padding: 18px 20px;
    font-size: 1rem;
    font-weight: 800;
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: rgba(19, 34, 63, 0.52);
}

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

.standard-card summary::after {
    content: "+";
    color: #dbe7ff;
    font-size: 1.2rem;
    line-height: 1;
}

.standard-card[open] summary::after {
    content: "−";
}

.standard-list {
    list-style: none;
    margin: 0;
    padding: 16px 18px 18px;
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
}

.standard-list li {
    display: flex;
    flex-direction: column;
    gap: 4px;
    padding: 12px 14px;
    border-radius: 14px;
    background: rgba(8, 18, 37, 0.66);
    border: 1px solid rgba(52, 80, 127, 0.3);
}

.standard-list li span {
    font-weight: 700;
    color: #eef5ff;
}

.density-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 18px;
}

.density-card {
    padding: 22px;
}

.density-card-primary {
    border-color: rgba(47, 109, 246, 0.38);
}

.density-value {
    margin: 0 0 10px;
    font-size: clamp(1.5rem, 3vw, 2rem);
    line-height: 1;
    letter-spacing: -0.03em;
    font-weight: 800;
    color: #f6fbff;
}

.density-note {
    margin-top: 18px;
    padding: 18px 20px;
    border-radius: var(--mc-radius-xl);
    background: rgba(14, 27, 52, 0.62);
    border: 1px solid rgba(52, 80, 127, 0.28);
}

.density-note p {
    margin: 0;
    color: var(--mc-text-muted);
}

.cta-panel {
    margin-top: 22px;
    padding: 24px;
    display: flex;
    gap: 20px;
    align-items: center;
    justify-content: space-between;
}

@media (max-width: 1024px) {
    .formula-shell,
    .formula-grid,
    .standard-grid {
        grid-template-columns: 1fr;
    }

    .density-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .formula-copy h1 {
        max-width: 15ch;
    }
}

@media (max-width: 720px) {
    .section {
        padding: 20px 0 56px 0;
    }

    .container {
        width: min(calc(100% - 28px), var(--mc-container));
    }

    .formula-copy h1 {
        font-size: clamp(2rem, 9vw, 3rem);
        max-width: none;
    }

    .formula-actions,
    .cta-panel {
        flex-direction: column;
        align-items: stretch;
    }

    .formula-note-card,
    .formula-card,
    .standard-intro-card,
    .density-card,
    .cta-panel {
        padding: 20px;
    }

    .standard-list {
        grid-template-columns: 1fr;
    }
}