/* BT360 Marketing Site — Based on business-simulation.ru */

/* ============================================
   Reset & Base
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;

    /* Colors — extracted from business-simulation.ru */
    --color-text: #1a1a1a;
    --color-text-light: #6b7280;
    --color-background: #ffffff;
    --color-background-light: #f9fafb;
    --color-border: #e5e7eb;
    --color-primary: #1e3a8a;
    --color-accent: #ff6b4a;
    --color-accent-hover: #e55a35;

    /* Spacing */
    --space-xs: 8px;
    --space-sm: 16px;
    --space-md: 24px;
    --space-lg: 48px;
    --space-xl: 80px;
    --space-2xl: 120px;

    /* Layout */
    --container-width: 1200px;
    --border-radius: 12px;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--color-text);
    background: var(--color-background);
}

/* ============================================
   Typography
   ============================================ */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--space-md);
    color: var(--color-text);
}

h1 {
    font-size: clamp(2.5rem, 5vw + 1rem, 4.5rem);
    font-weight: 800;
    letter-spacing: -0.03em;
}

h2 {
    font-size: clamp(2rem, 4vw + 0.5rem, 3rem);
    font-weight: 800;
    letter-spacing: -0.02em;
}

h3 {
    font-size: clamp(1.5rem, 2.5vw + 0.5rem, 2rem);
    font-weight: 700;
}

p {
    margin-bottom: var(--space-md);
    line-height: 1.7;
}

ul {
    list-style: none;
    margin-bottom: var(--space-md);
}

li {
    margin-bottom: var(--space-sm);
    padding-left: var(--space-md);
    position: relative;
}

li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--color-accent);
    font-weight: bold;
    font-size: 1.2em;
}

a {
    color: var(--color-text);
    text-decoration: none;
    transition: color 0.2s ease;
}

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

strong {
    font-weight: 700;
    color: var(--color-text);
}

/* ============================================
   Layout
   ============================================ */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--space-md);
}

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

/* ============================================
   Header
   ============================================ */
.site-header {
    background: var(--color-background);
    padding: var(--space-md) 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--space-lg);
}

.logo a {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.logo-text {
    font-size: 2rem;
    font-weight: 800;
    line-height: 1;
    letter-spacing: -0.02em;
    color: var(--color-primary);
}

.logo-subtitle {
    font-size: 0.6875rem;
    font-weight: 500;
    color: var(--color-text-light);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.main-nav ul {
    display: flex;
    gap: var(--space-lg);
    list-style: none;
    margin: 0;
}

.main-nav li {
    margin: 0;
    padding: 0;
}

.main-nav li::before {
    display: none;
}

.main-nav a {
    font-size: 1rem;
    font-weight: 500;
    color: var(--color-text);
}

.main-nav a:hover {
    color: var(--color-primary);
}

.btn-login {
    padding: 14px 32px;
    background: var(--color-accent);
    color: var(--color-background);
    border: none;
    border-radius: 8px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-login:hover {
    background: var(--color-accent-hover);
    color: var(--color-background);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(255, 107, 74, 0.3);
}

/* ============================================
   Hero
   ============================================ */
.hero {
    padding: var(--space-2xl) 0;
    background: var(--color-background-light);
}

.hero-title {
    max-width: 950px;
    margin-bottom: var(--space-md);
}

.hero-lead {
    font-size: clamp(1.125rem, 1.8vw + 0.5rem, 1.375rem);
    line-height: 1.7;
    max-width: 800px;
    margin-bottom: var(--space-xl);
    color: var(--color-text-light);
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: var(--space-lg);
    margin-top: var(--space-xl);
}

.stat-item {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.stat-number {
    font-size: clamp(3.5rem, 7vw, 6rem);
    font-weight: 800;
    line-height: 1;
    letter-spacing: -0.03em;
    color: var(--color-primary);
}

.stat-label {
    font-size: 1.0625rem;
    line-height: 1.4;
    color: var(--color-text-light);
}

/* ============================================
   About Section
   ============================================ */
.about-section {
    background: var(--color-background);
}

.section-title {
    margin-bottom: var(--space-lg);
    font-size: clamp(2rem, 3.5vw, 2.75rem);
}

.not-grid, .is-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-md);
    margin-bottom: var(--space-xl);
}

.not-item, .is-item {
    padding: var(--space-lg);
    background: var(--color-background-light);
    border-radius: var(--border-radius);
}

.not-item p, .is-item p {
    margin: 0;
    font-size: 1rem;
    line-height: 1.7;
    color: var(--color-text);
}

.project-description {
    max-width: 800px;
    margin-top: var(--space-xl);
}

.project-description p {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--color-text);
}

/* ============================================
   Categories Preview
   ============================================ */
.categories-preview {
    background: var(--color-background-light);
}

.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: var(--space-md);
    margin-top: var(--space-xl);
}

.category-card {
    padding: var(--space-lg);
    background: var(--color-background);
    border-radius: var(--border-radius);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
    display: block;
    transition: all 0.3s ease;
}

.category-card:hover {
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
    transform: translateY(-4px);
}

.category-title {
    font-size: 1.375rem;
    font-weight: 700;
    margin-bottom: var(--space-xs);
    color: var(--color-primary);
}

.category-count {
    font-size: 0.9375rem;
    color: var(--color-accent);
    font-weight: 600;
    margin-bottom: var(--space-md);
}

.category-description {
    font-size: 1rem;
    line-height: 1.7;
    color: var(--color-text-light);
    margin: 0;
}

.cta-section {
    text-align: center;
    padding: var(--space-xl) 0 0;
    margin-top: var(--space-xl);
}

.cta-section p {
    font-size: 1.25rem;
    margin-bottom: var(--space-lg);
    color: var(--color-text);
}

.btn-primary {
    display: inline-block;
    padding: 18px 48px;
    background: var(--color-accent);
    color: var(--color-background);
    border-radius: 8px;
    font-weight: 600;
    font-size: 1.125rem;
    transition: all 0.3s ease;
    box-shadow: 0 4px 14px rgba(255, 107, 74, 0.25);
}

.btn-primary:hover {
    background: var(--color-accent-hover);
    color: var(--color-background);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(255, 107, 74, 0.35);
}

/* ============================================
   Methodology
   ============================================ */
.methodology {
    background: var(--color-background);
}

.methodology-content {
    max-width: 850px;
}

.methodology-content p {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--color-text);
}

.methodology-content ul {
    margin: var(--space-lg) 0;
}

.methodology-content li {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--color-text);
}

/* ============================================
   Partner Section
   ============================================ */
.partner-section {
    padding: var(--space-xl) 0;
    text-align: center;
    background: var(--color-background-light);
}

.partner-label {
    font-size: 0.875rem;
    color: var(--color-text-light);
    margin-bottom: var(--space-md);
    text-transform: uppercase;
    letter-spacing: 0.15em;
    font-weight: 600;
}

.partner-logo {
    display: inline-block;
    transition: opacity 0.2s ease;
}

.partner-logo:hover {
    opacity: 0.8;
}

.partner-name {
    font-size: 2rem;
    font-weight: 800;
    letter-spacing: 0.05em;
    color: var(--color-primary);
}

/* ============================================
   Footer
   ============================================ */
.site-footer {
    background: var(--color-background);
    border-top: 1px solid var(--color-border);
    padding: var(--space-xl) 0 var(--space-lg);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: var(--space-lg);
    margin-bottom: var(--space-lg);
}

.footer-logo {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.footer-logo .logo-text {
    font-size: 1.75rem;
}

.footer-nav {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.footer-nav a {
    font-size: 1rem;
    color: var(--color-text-light);
}

.footer-nav a:hover {
    color: var(--color-primary);
}

.footer-partner {
    text-align: right;
}

.footer-partner p {
    font-size: 0.875rem;
    color: var(--color-text-light);
    margin-bottom: var(--space-xs);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    font-weight: 600;
}

.footer-partner a {
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--color-primary);
}

.footer-bottom {
    padding-top: var(--space-lg);
    border-top: 1px solid var(--color-border);
    text-align: center;
}

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

/* ============================================
   Categories Detail Page
   ============================================ */
.categories-detail {
    background: var(--color-background);
}

.category-block {
    padding: var(--space-xl) 0;
    border-bottom: 1px solid var(--color-border);
}

.category-block:last-child {
    border-bottom: none;
}

.category-block h2 {
    font-size: clamp(1.75rem, 3vw, 2.25rem);
    color: var(--color-primary);
    margin-bottom: var(--space-sm);
}

.category-meta {
    font-size: 1rem;
    color: var(--color-accent);
    font-weight: 600;
    margin-bottom: var(--space-lg);
}

.category-content p {
    font-size: 1.0625rem;
    line-height: 1.8;
    color: var(--color-text);
    margin-bottom: var(--space-md);
}

.cta-section-full {
    background: var(--color-background-light);
    padding: var(--space-xl) 0;
    text-align: center;
}

.cta-section-full h2 {
    font-size: clamp(1.75rem, 3vw, 2.5rem);
    margin-bottom: var(--space-sm);
}

.cta-section-full p {
    font-size: 1.125rem;
    color: var(--color-text-light);
    margin-bottom: var(--space-lg);
}

/* ============================================
   Tests Page
   ============================================ */
.tests-listing {
    background: var(--color-background);
}

.tests-category-section {
    margin-bottom: var(--space-2xl);
}

.tests-category-section h2 {
    font-size: clamp(1.75rem, 3vw, 2.25rem);
    color: var(--color-primary);
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-md);
    border-bottom: 2px solid var(--color-accent);
}

.tests-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--space-md);
}

.test-card {
    padding: var(--space-md);
    background: var(--color-background-light);
    border-radius: var(--border-radius);
    border-left: 4px solid var(--color-accent);
}

.test-card h3 {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: var(--space-xs);
}

.test-author {
    font-size: 0.875rem;
    color: var(--color-text-light);
    font-style: italic;
    margin-bottom: var(--space-sm);
}

.test-description {
    font-size: 0.9375rem;
    line-height: 1.6;
    color: var(--color-text);
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 992px) {
    .header-content {
        flex-wrap: wrap;
    }

    .main-nav {
        order: 3;
        flex-basis: 100%;
        margin-top: var(--space-sm);
    }

    .main-nav ul {
        justify-content: center;
        flex-wrap: wrap;
        gap: var(--space-md);
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--space-lg);
    }

    .footer-partner {
        text-align: left;
    }
}

@media (max-width: 768px) {
    :root {
        --space-xl: 64px;
        --space-2xl: 96px;
    }

    section {
        padding: var(--space-xl) 0;
    }

    .hero-stats {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
        gap: var(--space-md);
    }

    .not-grid, .is-grid {
        grid-template-columns: 1fr;
    }

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

@media (max-width: 480px) {
    :root {
        --space-lg: 32px;
        --space-xl: 48px;
        --space-2xl: 72px;
    }

    .btn-login {
        padding: 12px 24px;
        font-size: 0.9375rem;
    }

    .btn-primary {
        padding: 16px 36px;
        font-size: 1.0625rem;
    }
}