:root {
    --max-width: 900px;
    --bg: #FAFAFB;
    --text: #102A43;
    --muted: #334E68;
    --accent: #0B69FF;
    /* azul como destaque */
    --container-padding: 1rem;
}

* {
    box-sizing: border-box
}

html,
body {
    height: 100%
}

ol {
    list-style: none;
}
body {
    margin: 0;
    font-family: "Merriweather", Georgia, serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

header {
    background: linear-gradient(180deg, #fff 0%, #f7f9fc 100%);
    border-bottom: 1px solid #e6eef6;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: var(--container-padding);
    padding-top: 0px;
    padding-bottom: 0px;
}

nav ul {
    display: flex;
    gap: 1rem;
    list-style: none;
    padding: 0;
    margin: 0
}

nav a {
    text-decoration: none;
    color: var(--muted);
    font-family: Roboto, Arial, sans-serif
}

nav a:hover {
    color: var(--accent)
}

h1 {
    font-family: Roboto, Arial, sans-serif;
    margin: 0;
    padding: 0.5rem 0
}

h2 {
    font-family: Roboto, Arial, sans-serif;
    color: var(--muted)
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.75rem 0
}

.site-header nav ul {
    display: flex;
    align-items: center;
    gap: 1rem
}

.site-brand {
    margin-left: 20px;

}

.site-brand h1 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.35rem
}

.menu-toggle {
    background: transparent;
    border: 1px solid transparent;
    padding: 0.4rem;
    border-radius: 8px;
    margin-left: auto;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer
}

.menu-toggle:focus {
    outline: 2px solid var(--accent)
}

.menu-toggle.is-open {
    background: rgba(11, 105, 255, 0.08);
    border-color: rgba(11, 105, 255, 0.15)
}

.menu-toggle.is-open .icon {
    color: var(--accent)
}

@media(max-width:719px) {
    .site-header {
        position: relative
    }

    .site-header .container {
        position: relative
    }

    #primary-menu {
        display: none;
        position: absolute;
        top: calc(100% + 0.75rem);
        right: var(--container-padding);
        left: var(--container-padding);
        padding: 1rem;
        background: #fff;
        border: 1px solid #e6eef6;
        border-radius: 12px;
        box-shadow: 0 18px 30px rgba(16, 42, 67, 0.12);
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
        z-index: 20;
    }

    #primary-menu.is-open {
        display: flex
    }
}

@media(min-width:720px) {
    .menu-toggle {
        display: none
    }

    #primary-menu {
        display: flex !important;
        position: static;
        flex-direction: row;
        padding: 0;
        background: transparent;
        border: none;
        box-shadow: none;
    }
}

main {
    padding: 0.6rem 1.25rem 0.5rem;

}

section {
    margin-bottom: 1.25rem
}

.container-content {
    max-width: 720px;
    margin: 0 auto;
    padding: 0.5rem 1rem 1.1rem;
    padding-top: 0px;
    padding-bottom: 0px;
}

.icon {
    width: 1.7em;
    height: 1.7em;
    vertical-align: middle;
    margin-right: 0.45rem;
    fill: currentColor
}

.icon--standalone {
    margin-right: 0;
    width: 1.9em;
    height: 1.9em;
    display: block
}

.nav-list {
    display: flex;
    gap: 1rem;
    align-items: center;
    padding: 0;
    margin: 0;
    list-style: none
}

.centered {
    margin: 0 auto;
    text-align: center
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0
}

.btn {
    display: inline-block;
    padding: 0.45rem 0.9rem;
    border-radius: 8px;
    text-decoration: none;
    font-family: Roboto, Arial, sans-serif
}

.btn-primary {
    background: var(--accent);
    color: #fff;
    border: 1px solid rgba(11, 105, 255, 0.9)
}

.btn-outline {
    background: transparent;
    color: var(--accent);
    border: 1px solid var(--accent)
}

blockquote {
    border-left: 4px solid #e6eef6;
    padding: 0.5rem 1rem;
    color: var(--muted);
    background: linear-gradient(90deg, rgba(11, 105, 255, 0.03), transparent)
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0
}

th,
td {
    padding: 0.5rem;
    border: 1px solid #e6eef6;
    text-align: left
}

th {
    background: #f7fafc;
    font-family: Roboto, Arial, sans-serif
}

/* Footer */
.site-footer {
    background: #fff;
    border-top: 1px solid #e6eef6;
    padding: 1rem 0;
}

.footer-content {
    display: grid;
    gap: 1.75rem;
    text-align: center
}

.footer-column {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    align-items: center
}

.footer-column--social {
    text-align: center
}

.footer-heading {
    margin: 0;
    font-family: Roboto, Arial, sans-serif;
    font-size: 1rem;
    color: var(--muted)
}

.footer-logo {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    margin: 0;
    font-family: Roboto, Arial, sans-serif;
    font-weight: 600;
    color: var(--muted)
}

.footer-description {
    margin: 0;
    color: var(--muted)
}

.site-footer .footer-links {
    display: grid;
    gap: 0.6rem;
    list-style: none;
    padding: 0;
    margin: 0;
    justify-items: center
}

.footer-social {
    display: inline-flex;
    gap: 0.75rem;
    list-style: none;
    padding: 0;
    margin: 0
}

.footer-social a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 12px;
    background: rgba(11, 105, 255, 0.08);
    color: var(--accent);
    transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease
}

.footer-social a:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 20px rgba(16, 42, 67, 0.12);
    background: rgba(11, 105, 255, 0.16)
}

.footer-base {
    border-top: 1px solid #e6eef6;
    margin-top: 2rem;
    padding-top: 1rem;
    text-align: center;
    color: var(--muted);
    font-size: 0.9rem
}

.footer-links a {
    color: var(--muted);
    text-decoration: none
}

.footer-links a:hover {
    color: var(--accent)
}

@media(min-width:720px) {
    main {
        padding: 1.1rem 2.2rem 2.85rem;
    }

    nav ul {
        gap: 1.5rem
    }

    .footer-content {
        grid-template-columns: repeat(3, minmax(0, 1fr));
        text-align: left
    }

    .footer-column {
        align-items: flex-start
    }

    .site-footer .footer-links {
        justify-items: flex-start
    }

    .footer-logo {
        justify-content: flex-start
    }

    .footer-description {
        max-width: 28ch
    }

    .footer-column--social {
        align-items: center;
        text-align: center
    }
}

.text-muted {
    color: var(--muted)
}

.katex {
    font-size: 1em
}

.equation-calculator {
    background: #f8f9fb;
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.08);
    max-width: 480px;
    margin: 2rem auto;
    font-family: Roboto, Arial, sans-serif;
}

.equation-calculator h3 {
    margin-top: 0;
    font-size: 1.25rem;
    color: #333;
    text-align: center;
}

.equation-calculator p {
    color: #555;
    font-size: 0.95rem;
    text-align: center;
    margin-bottom: 1.1rem;
}

.equation-form {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.equation-form .form-field {
    display: flex;
    flex-direction: column;
}

.equation-form label {
    font-size: 0.9rem;
    margin-bottom: 5px;
    color: #444;
}

.equation-form input,
.equation-form select,
.equation-form textarea {
    padding: 10px;
    font-size: 1rem;
    border: 1px solid #cfd7e3;
    border-radius: 8px;
    outline: none;
    transition: border-color 0.2s ease;
}

.equation-form input:focus,
.equation-form select:focus,
.equation-form textarea:focus {
    border-color: var(--accent);
}

.equation-form textarea {
    min-height: 120px;
    resize: vertical;
}

.equation-form button {
    margin-top: 5px;
    padding: 11px;
    background: var(--accent);
    color: #fff;
    font-size: 1rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.2s ease;
}

.equation-form button:hover {
    background: #0a5dde;
}

.equation-output {
    display: block;
    margin-top: 1rem;
    padding: 12px;
    background: #eef1ff;
    border-left: 4px solid var(--accent);
    border-radius: 6px;
    color: #333;
    font-size: 0.95rem;
}

.module-hero {
    background: linear-gradient(135deg, rgba(11, 105, 255, 0.08), rgba(11, 105, 255, 0.02));
    border: 1px solid #dae4f5;
    border-radius: 20px;
    padding: 1.75rem;
    box-shadow: 0 25px 45px rgba(16, 42, 67, 0.08);
    margin-bottom: 2rem;
}

.module-hero h1 {
    font-size: 2rem;
    margin-bottom: 0.6rem;
}

.module-hero p {
    margin-top: 0.4rem;
}

.module-hero__equation {
    font-size: 1.05rem;
    color: var(--accent);
    margin: 1rem 0;
    font-family: "Merriweather", Georgia, serif;
}

.eyebrow {
    text-transform: uppercase;
    font-size: 0.78rem;
    letter-spacing: 0.08em;
    color: var(--accent);
    font-family: Roboto, Arial, sans-serif;
    margin: 0;
}

.module-meta {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1rem;
    margin: 1.25rem 0;
}

.module-meta dl {
    margin: 0;
    padding: 1rem;
    background: #fff;
    border-radius: 14px;
    border: 1px solid #e6eef6;
}

.module-meta dt {
    font-family: Roboto, Arial, sans-serif;
    font-weight: 600;
    font-size: 0.85rem;
    color: var(--muted);
    margin-bottom: 0.25rem;
}

.module-meta dd {
    margin: 0;
}

.module-meta--compact dl {
    padding: 0.75rem 1rem;
    background: #f8fafc;
}

.module-section {
    margin-bottom: 2.5rem;
}

.cta-group {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.toc-grid {
    display: grid;
    gap: 1.25rem;
}

@media(min-width:720px) {
    .toc-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

.toc-card {
    border: 1px solid #e0e8f5;
    border-radius: 16px;
    background: #fff;
    padding: 1.25rem;
    box-shadow: 0 12px 24px rgba(16, 42, 67, 0.06);
    display: flex;
    flex-direction: column;
    gap: 0.85rem;
}

.toc-card__header h3 {
    margin: 0.2rem 0;
}

.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.2rem 0.6rem;
    border-radius: 999px;
    background: rgba(11, 105, 255, 0.12);
    color: var(--accent);
    font-size: 0.8rem;
    font-family: Roboto, Arial, sans-serif;
}

.toc-card__list {
    margin: 0;
    padding-left: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.toc-card__list li {
    font-size: 0.95rem;
}

.toc-card__list a {
    font-weight: 600;
    color: var(--text);
    text-decoration: none;
}

.toc-card__list a:hover {
    color: var(--accent);
}

.toc-card__list span {
    display: block;
    font-size: 0.82rem;
    color: var(--muted);
}

.feature-list {
    list-style: none;
    padding: 0;
    margin: 1.1rem 0;
    display: grid;
    gap: 0.75rem;
}

.feature-list li {
    padding-left: 0.5rem;
}

.callout {
    border-left: 4px solid var(--accent);
    padding: 0.75rem 1rem;
    background: rgba(11, 105, 255, 0.06);
    border-radius: 12px;
    color: var(--muted);
}

.workflow {
    counter-reset: steps;
    list-style: none;
    padding: 0;
    margin: 1rem 0 1.5rem;
}

.workflow li {
    position: relative;
    padding-left: 2.2rem;
    margin-bottom: 0.9rem;
}

.workflow li::before {
    counter-increment: steps;
    content: counter(steps);
    position: absolute;
    left: 0;
    top: 0.25rem;
    width: 1.5rem;
    height: 1.5rem;
    border-radius: 50%;
    background: var(--accent);
    color: #fff;
    font-size: 0.85rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.breadcrumb {
    margin: 1rem 0 1.5rem;
    font-family: Roboto, Arial, sans-serif;
    font-size: 0.9rem;
    color: var(--muted);
}

.breadcrumb ol {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 0.35rem;
}

.breadcrumb a {
    color: var(--accent);
    text-decoration: none;
}

.breadcrumb li::after {
    content: "/";
    margin-left: 0.35rem;
    color: rgba(16, 42, 67, 0.4);
}

.breadcrumb li:last-child::after {
    content: "";
}

.lesson {
    background: #fff;
    border: 1px solid #dfe7f3;
    border-radius: 20px;
    padding: 1.75rem;
    box-shadow: 0 18px 30px rgba(16, 42, 67, 0.08);
    margin-bottom: 2.5rem;
}

.lesson-header {
    border-bottom: 1px solid #e7eef8;
    padding-bottom: 1.25rem;
    margin-bottom: 1.5rem;
}

.lesson-tag {
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-size: 0.78rem;
    color: var(--accent);
    margin: 0;
}

.lesson-objectives ul,
.practice-list,
.checklist {
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    gap: 0.5rem;
}

.lesson-objectives li,
.practice-list li,
.checklist li {
    padding-left: 1.35rem;
    position: relative;
}

.lesson-objectives li::before,
.practice-list li::before,
.checklist li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--accent);
}

.concept-grid {
    display: grid;
    gap: 1rem;
    margin-top: 1rem;
}

@media(min-width:720px) {
    .concept-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

.concept-card {
    background: #f8faff;
    border: 1px solid #e0e8f5;
    border-radius: 16px;
    padding: 1rem 1.15rem;
}

.concept-card h3 {
    margin-top: 0;
}

.formula {
    color: var(--accent);
    font-weight: 600;
    margin-top: 0.6rem;
}

.example-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    gap: 1rem;
}

.example-list h3 {
    margin-bottom: 0.35rem;
}

.quick-tool,
.callout-card {
    border: 1px solid #dfe7f3;
    border-radius: 14px;
    padding: 1rem;
    background: rgba(11, 105, 255, 0.05);
    margin-top: 1rem;
}

.tips-box {
    border-left: 4px solid var(--accent);
    padding: 0.75rem 1rem;
    background: rgba(11, 105, 255, 0.06);
    border-radius: 10px;
    margin: 1rem 0;
}