:root {
    --color-primary: #0066cc;
    --color-primary-dark: #004d99;
    --color-primary-light: #e6f0fa;
    --color-bg: #ffffff;
    --color-bg-alt: #f8f9fa;
    --color-text: #1a1a2e;
    --color-text-light: #5a5a6e;
    --color-border: #e1e4e8;
    --color-success: #28a745;
    --color-warning: #ffc107;
    --color-error: #dc3545;
    --font-stack: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --max-width: 1200px;
    --header-height: 64px;
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --transition: 0.2s ease;
}

*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

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

body {
    font-family: var(--font-stack);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

main {
    flex: 1;
}

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

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition);
}

a:hover {
    color: var(--color-primary-dark);
}

h1,
h2,
h3,
h4,
h5,
h6 {
    line-height: 1.3;
    font-weight: 600;
    color: var(--color-text);
}

h1 {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
}

h2 {
    font-size: clamp(1.5rem, 3vw, 2rem);
}

h3 {
    font-size: clamp(1.25rem, 2.5vw, 1.5rem);
}

h4 {
    font-size: 1.125rem;
}

p {
    margin-bottom: var(--spacing-md);
}

p:last-child {
    margin-bottom: 0;
}

ul,
ol {
    padding-left: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

li {
    margin-bottom: var(--spacing-xs);
}

code {
    background: var(--color-bg-alt);
    padding: 0.125rem 0.375rem;
    border-radius: var(--radius-sm);
    font-size: 0.875em;
    font-family: 'SF Mono', Consolas, monospace;
}

pre {
    background: var(--color-text);
    color: #f8f8f2;
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    overflow-x: auto;
    margin-bottom: var(--spacing-md);
}

pre code {
    background: none;
    padding: 0;
    color: inherit;
}

.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    height: var(--header-height);
}

.header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.logo:hover {
    color: var(--color-primary);
}

.logo svg {
    width: 32px;
    height: 32px;
}

.nav {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

.nav__list {
    display: flex;
    gap: var(--spacing-lg);
    list-style: none;
    padding: 0;
    margin: 0;
}

.nav__link {
    color: var(--color-text);
    font-weight: 500;
    padding: var(--spacing-sm) 0;
    position: relative;
}

.nav__link:hover,
.nav__link--active {
    color: var(--color-primary);
}

.nav__toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
}

.nav__toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text);
    margin: 6px 0;
    transition: var(--transition);
}

.hero {
    padding: var(--spacing-3xl) 0;
    background: linear-gradient(135deg, var(--color-primary-light) 0%, var(--color-bg) 100%);
}

.hero__content {
    max-width: 700px;
}

.hero__title {
    margin-bottom: var(--spacing-md);
}

.hero__subtitle {
    font-size: 1.125rem;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-xl);
}

.hero__actions {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: transform var(--transition), background-color var(--transition);
    text-decoration: none;
}

.btn:hover {
    transform: translateY(-2px);
}

.btn--primary {
    background: var(--color-primary);
    color: #fff;
}

.btn--primary:hover {
    background: var(--color-primary-dark);
    color: #fff;
}

.btn--secondary {
    background: var(--color-bg);
    color: var(--color-primary);
    border: 2px solid var(--color-primary);
}

.btn--secondary:hover {
    background: var(--color-primary-light);
    color: var(--color-primary);
}

.section {
    padding: var(--spacing-3xl) 0;
}

.section--alt {
    background: var(--color-bg-alt);
}

.section__header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.section__title {
    margin-bottom: var(--spacing-sm);
}

.section__subtitle {
    color: var(--color-text-light);
    max-width: 600px;
    margin: 0 auto;
}

.grid {
    display: grid;
    gap: var(--spacing-xl);
}

.grid--2 {
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.grid--3 {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid--4 {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.card {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    transition: transform var(--transition), box-shadow var(--transition);
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
}

.card__icon {
    width: 48px;
    height: 48px;
    background: var(--color-primary-light);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
    color: var(--color-primary);
}

.card__title {
    margin-bottom: var(--spacing-sm);
}

.card__text {
    color: var(--color-text-light);
    margin-bottom: var(--spacing-md);
}

.card__link {
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.card__link::after {
    content: '→';
    transition: transform var(--transition);
}

.card__link:hover::after {
    transform: translateX(4px);
}

.article-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.article-list__item {
    border-bottom: 1px solid var(--color-border);
    margin: 0;
}

.article-list__item:last-child {
    border-bottom: none;
}

.article-list__link {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md) 0;
    color: var(--color-text);
}

.article-list__link:hover {
    color: var(--color-primary);
}

.article-list__link::after {
    content: '→';
    color: var(--color-text-light);
    transition: transform var(--transition), color var(--transition);
}

.article-list__link:hover::after {
    transform: translateX(4px);
    color: var(--color-primary);
}

.article {
    max-width: 800px;
    margin: 0 auto;
    padding: var(--spacing-2xl) var(--spacing-md);
}

.article__header {
    margin-bottom: var(--spacing-2xl);
}

.article__meta {
    color: var(--color-text-light);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-md);
}

.article__content h2 {
    margin-top: var(--spacing-2xl);
    margin-bottom: var(--spacing-md);
}

.article__content h3 {
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
}

.article__content p,
.article__content ul,
.article__content ol {
    margin-bottom: var(--spacing-md);
}

.breadcrumb {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    list-style: none;
    padding: var(--spacing-md) 0;
    margin: 0;
    font-size: 0.875rem;
}

.breadcrumb__item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin: 0;
}

.breadcrumb__item:not(:last-child)::after {
    content: '/';
    color: var(--color-text-light);
}

.breadcrumb__link {
    color: var(--color-text-light);
}

.breadcrumb__link:hover {
    color: var(--color-primary);
}

.breadcrumb__current {
    color: var(--color-text);
}

.cta {
    background: var(--color-primary);
    color: #fff;
    text-align: center;
    padding: var(--spacing-3xl) var(--spacing-md);
}

.cta__title {
    color: #fff;
    margin-bottom: var(--spacing-md);
}

.cta__text {
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto var(--spacing-xl);
}

.cta .btn--secondary {
    background: #fff;
    border-color: #fff;
}

.footer {
    background: var(--color-text);
    color: #fff;
    padding: var(--spacing-2xl) 0 var(--spacing-md);
}

.footer__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
}

.footer__title {
    color: #fff;
    font-size: 1rem;
    margin-bottom: var(--spacing-md);
}

.footer__list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer__list li {
    margin-bottom: var(--spacing-sm);
}

.footer__link {
    color: rgba(255, 255, 255, 0.7);
    transition: color var(--transition);
}

.footer__link:hover {
    color: #fff;
}

.footer__bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--spacing-md);
    text-align: center;
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.875rem;
}

.form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.form__group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.form__label {
    font-weight: 500;
    font-size: 0.875rem;
}

.form__input,
.form__textarea {
    padding: 0.75rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-family: inherit;
    transition: border-color var(--transition);
}

.form__input:focus,
.form__textarea:focus {
    outline: none;
    border-color: var(--color-primary);
}

.form__textarea {
    min-height: 150px;
    resize: vertical;
}

.features {
    display: grid;
    gap: var(--spacing-md);
}

.feature {
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-start;
}

.feature__icon {
    flex-shrink: 0;
    width: 24px;
    height: 24px;
    color: var(--color-primary);
}

.feature__content h4 {
    margin-bottom: var(--spacing-xs);
}

.feature__content p {
    color: var(--color-text-light);
    font-size: 0.9375rem;
    margin: 0;
}

.alert {
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
}

.alert--info {
    background: var(--color-primary-light);
    border-left: 4px solid var(--color-primary);
}

.alert--warning {
    background: #fff8e6;
    border-left: 4px solid var(--color-warning);
}

.alert--error {
    background: #ffe6e6;
    border-left: 4px solid var(--color-error);
}

.alert--success {
    background: #e6f4ea;
    border-left: 4px solid var(--color-success);
}

.table-wrapper {
    overflow-x: auto;
    margin-bottom: var(--spacing-md);
}

table {
    width: 100%;
    border-collapse: collapse;
}

th,
td {
    padding: var(--spacing-sm) var(--spacing-md);
    text-align: left;
    border-bottom: 1px solid var(--color-border);
}

th {
    background: var(--color-bg-alt);
    font-weight: 600;
}

.page-header {
    background: var(--color-bg-alt);
    padding: var(--spacing-2xl) 0;
    margin-bottom: var(--spacing-2xl);
}

.page-header__title {
    margin-bottom: var(--spacing-sm);
}

.page-header__subtitle {
    color: var(--color-text-light);
    max-width: 600px;
}

.steps {
    counter-reset: step;
}

.step {
    position: relative;
    padding-left: var(--spacing-2xl);
    padding-bottom: var(--spacing-xl);
}

.step::before {
    counter-increment: step;
    content: counter(step);
    position: absolute;
    left: 0;
    width: 28px;
    height: 28px;
    background: var(--color-primary);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.875rem;
}

.step:not(:last-child)::after {
    content: '';
    position: absolute;
    left: 13px;
    top: 36px;
    bottom: 0;
    width: 2px;
    background: var(--color-border);
}

.step__title {
    margin-bottom: var(--spacing-sm);
}

.step__content {
    color: var(--color-text-light);
}

.skip-link {
    position: absolute;
    top: -100%;
    left: var(--spacing-md);
    background: var(--color-primary);
    color: #fff;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    z-index: 1000;
}

.skip-link:focus {
    top: var(--spacing-md);
}

.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;
}

@media (max-width: 768px) {
    .nav__list {
        display: none;
        position: absolute;
        top: var(--header-height);
        left: 0;
        right: 0;
        background: var(--color-bg);
        flex-direction: column;
        padding: var(--spacing-md);
        border-bottom: 1px solid var(--color-border);
        gap: 0;
    }

    .nav__list.active {
        display: flex;
    }

    .nav__link {
        display: block;
        padding: var(--spacing-md);
    }

    .nav__toggle {
        display: block;
    }

    .hero {
        padding: var(--spacing-2xl) 0;
    }

    .section {
        padding: var(--spacing-2xl) 0;
    }

    .footer__grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero__actions {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }
}