/* ==========================================================================
   CSS Custom Properties
   ========================================================================== */
:root {
    --color-primary: #1a5276;
    --color-primary-dark: #0e3650;
    --color-primary-light: #2980b9;
    --color-secondary: #27ae60;
    --color-secondary-dark: #1e8449;
    --color-white: #ffffff;
    --color-gray-50: #f8f9fa;
    --color-gray-100: #e9ecef;
    --color-gray-200: #dee2e6;
    --color-gray-600: #6c757d;
    --color-gray-800: #343a40;
    --color-gray-900: #212529;
    --color-danger: #e74c3c;

    --font-family: 'Segoe UI', -apple-system, BlinkMacSystemFont, Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.5rem;
    --font-size-2xl: 2rem;
    --font-size-3xl: 2.5rem;
    --line-height-base: 1.7;
    --line-height-heading: 1.25;

    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;

    --container-max: 1200px;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --transition: 0.2s ease;
}

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

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

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: var(--line-height-base);
    color: var(--color-gray-800);
    background-color: var(--color-white);
    -webkit-font-smoothing: antialiased;
}

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

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

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

ul, ol {
    list-style: none;
}

/* ==========================================================================
   Layout
   ========================================================================== */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--space-md);
}

/* ==========================================================================
   Typography
   ========================================================================== */
h1, h2, h3, h4 {
    color: var(--color-gray-900);
    line-height: var(--line-height-heading);
    font-weight: 700;
}

h1 { font-size: var(--font-size-2xl); margin-bottom: var(--space-lg); }
h2 { font-size: var(--font-size-xl); margin-bottom: var(--space-md); }
h3 { font-size: var(--font-size-lg); margin-bottom: var(--space-sm); }

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

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-sm);
    font-size: var(--font-size-base);
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    border: 2px solid transparent;
    transition: all var(--transition);
    text-decoration: none;
    line-height: 1.4;
}

.btn--cta {
    background-color: var(--color-secondary);
    color: var(--color-white);
    border-color: var(--color-secondary);
}

.btn--cta:hover {
    background-color: var(--color-secondary-dark);
    border-color: var(--color-secondary-dark);
    color: var(--color-white);
}

.btn--outline {
    background-color: transparent;
    color: var(--color-white);
    border-color: var(--color-white);
}

.btn--outline:hover {
    background-color: var(--color-white);
    color: var(--color-primary);
}

.btn--primary {
    background-color: var(--color-primary);
    color: var(--color-white);
    border-color: var(--color-primary);
}

.btn--primary:hover {
    background-color: var(--color-primary-dark);
    border-color: var(--color-primary-dark);
    color: var(--color-white);
}

.btn--sm {
    padding: 0.5rem 1rem;
    font-size: var(--font-size-sm);
}

.btn--lg {
    padding: 1rem 2rem;
    font-size: var(--font-size-lg);
}

/* ==========================================================================
   Header / Navigation
   ========================================================================== */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background-color: var(--color-white);
    box-shadow: var(--shadow-sm);
    border-bottom: 3px solid var(--color-primary);
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
    gap: var(--space-md);
}

.site-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-weight: 700;
    font-size: var(--font-size-lg);
    color: var(--color-primary);
    text-decoration: none;
    white-space: nowrap;
    flex-shrink: 0;
}

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

/* Mobile nav toggle */
.nav-toggle {
    display: none;
}

.nav-toggle-label {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    cursor: pointer;
    position: relative;
    z-index: 101;
}

.nav-toggle-label span,
.nav-toggle-label span::before,
.nav-toggle-label span::after {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--color-gray-800);
    border-radius: 2px;
    transition: all var(--transition);
    position: relative;
}

.nav-toggle-label span::before,
.nav-toggle-label span::after {
    content: '';
    position: absolute;
    left: 0;
}

.nav-toggle-label span::before { top: -7px; }
.nav-toggle-label span::after { top: 7px; }

.nav-toggle:checked ~ .nav-toggle-label span {
    background-color: transparent;
}

.nav-toggle:checked ~ .nav-toggle-label span::before {
    top: 0;
    transform: rotate(45deg);
}

.nav-toggle:checked ~ .nav-toggle-label span::after {
    top: 0;
    transform: rotate(-45deg);
}

.main-nav {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background-color: var(--color-white);
    box-shadow: var(--shadow-md);
    border-top: 1px solid var(--color-gray-100);
}

.nav-toggle:checked ~ .main-nav {
    display: block;
}

.main-nav ul {
    display: flex;
    flex-direction: column;
}

.main-nav > ul > li > a {
    display: block;
    padding: var(--space-md) var(--space-lg);
    color: var(--color-gray-800);
    font-weight: 500;
    border-bottom: 1px solid var(--color-gray-100);
}

.main-nav > ul > li > a:hover,
.main-nav > ul > li > a.active {
    color: var(--color-primary);
    background-color: var(--color-gray-50);
}

.main-nav .nav-dropdown-menu {
    background-color: var(--color-gray-50);
    display: none;
}

@media (max-width: 1023px) {
    .nav-toggle:checked ~ .main-nav .nav-dropdown-menu {
        display: block;
    }
}

.nav-dropdown-menu a {
    display: block;
    padding: var(--space-sm) var(--space-lg) var(--space-sm) var(--space-2xl);
    color: var(--color-gray-600);
    font-size: var(--font-size-sm);
    border-bottom: 1px solid var(--color-gray-100);
}

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

.header-cta {
    display: none;
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    color: var(--color-white);
    padding: var(--space-3xl) 0;
    text-align: center;
}

.hero h1 {
    color: var(--color-white);
    font-size: var(--font-size-2xl);
    max-width: 800px;
    margin: 0 auto var(--space-md);
}

.hero__subtitle {
    font-size: var(--font-size-lg);
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto var(--space-xl);
    line-height: var(--line-height-base);
}

.hero__actions {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
    align-items: center;
}

/* ==========================================================================
   Features Section
   ========================================================================== */
.features {
    padding: var(--space-3xl) 0;
    background-color: var(--color-gray-50);
}

.features > .container > h2 {
    text-align: center;
    margin-bottom: var(--space-2xl);
}

.features__grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-xl);
}

.feature-card {
    background: var(--color-white);
    padding: var(--space-xl);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    text-align: center;
    transition: box-shadow var(--transition), transform var(--transition);
}

.feature-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.feature-card__icon {
    width: 64px;
    height: 64px;
    margin: 0 auto var(--space-md);
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.feature-card__icon svg {
    width: 28px;
    height: 28px;
    stroke: var(--color-white);
    fill: none;
    stroke-width: 2;
}

.feature-card h3 {
    color: var(--color-primary);
}

.feature-card p {
    color: var(--color-gray-600);
    margin-bottom: 0;
}

/* ==========================================================================
   Article Cards
   ========================================================================== */
.articles-section {
    padding: var(--space-3xl) 0;
}

.articles-section > .container > h2 {
    text-align: center;
    margin-bottom: var(--space-2xl);
}

.articles__grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-xl);
}

.article-card {
    display: block;
    background: var(--color-white);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    transition: box-shadow var(--transition), transform var(--transition);
    text-decoration: none;
    color: inherit;
    border: 1px solid var(--color-gray-100);
}

.article-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
    border-color: var(--color-primary-light);
    color: inherit;
}

.article-card__icon {
    height: 160px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--color-gray-50) 0%, var(--color-gray-100) 100%);
}

.article-card__icon svg {
    width: 48px;
    height: 48px;
    stroke: var(--color-primary);
    fill: none;
    stroke-width: 1.5;
}

.article-card__body {
    padding: var(--space-lg);
}

.article-card__body h3 {
    font-size: var(--font-size-base);
    margin-bottom: var(--space-sm);
    color: var(--color-gray-900);
}

.article-card__body p {
    font-size: var(--font-size-sm);
    color: var(--color-gray-600);
    margin-bottom: var(--space-sm);
}

.article-card__link {
    font-size: var(--font-size-sm);
    color: var(--color-primary-light);
    font-weight: 600;
}

/* ==========================================================================
   CTA Section
   ========================================================================== */
.cta-section {
    padding: var(--space-3xl) 0;
    background-color: var(--color-gray-50);
    text-align: center;
}

.cta-section h2 {
    max-width: 600px;
    margin: 0 auto var(--space-md);
}

.cta-section p {
    color: var(--color-gray-600);
    max-width: 500px;
    margin: 0 auto var(--space-xl);
}

/* ==========================================================================
   Article / Prose Content
   ========================================================================== */
.article-page {
    padding: var(--space-2xl) 0 var(--space-3xl);
}

.article-page .container {
    max-width: 800px;
}

.prose h2 {
    margin-top: var(--space-2xl);
    padding-top: var(--space-lg);
    border-top: 1px solid var(--color-gray-100);
}

.prose h3 {
    margin-top: var(--space-xl);
}

.prose p {
    font-size: var(--font-size-base);
    color: var(--color-gray-800);
}

.prose ul, .prose ol {
    margin-bottom: var(--space-md);
    padding-left: var(--space-xl);
}

.prose ul { list-style: disc; }
.prose ol { list-style: decimal; }

.prose li {
    margin-bottom: var(--space-xs);
    line-height: var(--line-height-base);
}

.prose strong {
    color: var(--color-gray-900);
}

.prose table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: var(--space-xl);
    font-size: var(--font-size-sm);
}

.prose th, .prose td {
    padding: var(--space-sm) var(--space-md);
    border: 1px solid var(--color-gray-200);
    text-align: left;
}

.prose th {
    background-color: var(--color-primary);
    color: var(--color-white);
    font-weight: 600;
}

.prose tr:nth-child(even) {
    background-color: var(--color-gray-50);
}

.article-meta {
    color: var(--color-gray-600);
    font-size: var(--font-size-sm);
    margin-bottom: var(--space-xl);
}

.related-articles {
    margin-top: var(--space-3xl);
    padding-top: var(--space-xl);
    border-top: 2px solid var(--color-gray-100);
}

.related-articles h2 {
    border-top: none;
    padding-top: 0;
    margin-top: 0;
}

.related-articles ul {
    list-style: none;
    padding-left: 0;
}

.related-articles li {
    margin-bottom: var(--space-sm);
}

.related-articles a {
    font-weight: 500;
}

/* ==========================================================================
   Contact Page
   ========================================================================== */
.contact-page {
    padding: var(--space-2xl) 0 var(--space-3xl);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
}

.contact-info {
    background-color: var(--color-gray-50);
    padding: var(--space-xl);
    border-radius: var(--radius-md);
    order: -1;
}

.contact-info h2 {
    font-size: var(--font-size-xl);
    margin-bottom: var(--space-lg);
}

.contact-info-list {
    list-style: none;
    padding: 0;
}

.contact-info-list li {
    display: flex;
    align-items: flex-start;
    gap: var(--space-md);
    margin-bottom: var(--space-lg);
    color: var(--color-gray-800);
}

.contact-info-list svg {
    flex-shrink: 0;
    margin-top: 2px;
    color: var(--color-primary);
}

.contact-info-list a {
    color: var(--color-gray-800);
    font-weight: 500;
}

.contact-info-list a:hover {
    color: var(--color-primary);
}

/* Contact Form */
.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.form-field {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.form-field label {
    font-weight: 600;
    font-size: var(--font-size-sm);
    color: var(--color-gray-800);
}

.form-field input,
.form-field textarea {
    padding: 0.75rem;
    border: 1px solid var(--color-gray-200);
    border-radius: var(--radius-sm);
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    transition: border-color var(--transition), box-shadow var(--transition);
    width: 100%;
}

.form-field input:focus,
.form-field textarea:focus {
    outline: none;
    border-color: var(--color-primary-light);
    box-shadow: 0 0 0 3px rgba(41, 128, 185, 0.15);
}

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

.form-field--error input,
.form-field--error textarea {
    border-color: var(--color-danger);
}

.form-error {
    color: var(--color-danger);
    font-size: var(--font-size-sm);
}

.form-field--hp {
    position: absolute;
    left: -9999px;
    opacity: 0;
    height: 0;
    overflow: hidden;
}

.form-success {
    background-color: #d4edda;
    color: #155724;
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-sm);
    border: 1px solid #c3e6cb;
}

.form-global-error {
    background-color: #f8d7da;
    color: #721c24;
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-sm);
    border: 1px solid #f5c6cb;
}

/* ==========================================================================
   Breadcrumbs
   ========================================================================== */
.breadcrumbs {
    padding: var(--space-md) 0;
}

.breadcrumbs ol {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-xs);
    list-style: none;
    padding: 0;
    font-size: var(--font-size-sm);
    color: var(--color-gray-600);
}

.breadcrumbs li:not(:last-child)::after {
    content: '›';
    margin-left: var(--space-xs);
    color: var(--color-gray-600);
}

.breadcrumbs a {
    color: var(--color-primary-light);
}

.breadcrumbs span[aria-current] {
    color: var(--color-gray-600);
}

/* ==========================================================================
   Thank You Page
   ========================================================================== */
.thankyou-page {
    padding: var(--space-3xl) 0;
    text-align: center;
    min-height: 50vh;
    display: flex;
    align-items: center;
}

.thankyou-page .container {
    max-width: 600px;
}

.thankyou-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--space-xl);
    background: var(--color-secondary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.thankyou-icon svg {
    width: 40px;
    height: 40px;
    stroke: var(--color-white);
    fill: none;
    stroke-width: 2;
}

/* ==========================================================================
   404 Page
   ========================================================================== */
.error-page {
    padding: var(--space-3xl) 0;
    text-align: center;
    min-height: 50vh;
    display: flex;
    align-items: center;
}

.error-page .container {
    max-width: 600px;
}

.error-code {
    font-size: 6rem;
    font-weight: 800;
    color: var(--color-gray-200);
    line-height: 1;
    margin-bottom: var(--space-md);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
    background-color: var(--color-primary-dark);
    color: rgba(255, 255, 255, 0.8);
    padding: var(--space-3xl) 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-weight: 700;
    font-size: var(--font-size-lg);
    color: var(--color-white);
    margin-bottom: var(--space-md);
}

.footer-col h3 {
    color: var(--color-white);
    font-size: var(--font-size-base);
    margin-bottom: var(--space-md);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.footer-col ul {
    list-style: none;
    padding: 0;
}

.footer-col li {
    margin-bottom: var(--space-sm);
}

.footer-col a {
    color: rgba(255, 255, 255, 0.7);
    font-size: var(--font-size-sm);
    transition: color var(--transition);
}

.footer-col a:hover {
    color: var(--color-white);
}

.footer-col p {
    font-size: var(--font-size-sm);
    line-height: var(--line-height-base);
}

.footer-contact li {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.footer-contact svg {
    flex-shrink: 0;
    opacity: 0.7;
}

.footer-bottom {
    margin-top: var(--space-2xl);
    padding: var(--space-lg) 0;
    border-top: 1px solid rgba(255, 255, 255, 0.15);
    text-align: center;
}

.footer-bottom p {
    font-size: var(--font-size-sm);
    margin: 0;
    opacity: 0.7;
}

/* ==========================================================================
   Responsive — Tablet (768px+)
   ========================================================================== */
@media (min-width: 768px) {
    h1 { font-size: var(--font-size-3xl); }
    h2 { font-size: var(--font-size-2xl); }

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

    .hero {
        padding: var(--space-3xl) 0 calc(var(--space-3xl) + 1rem);
    }

    .hero h1 {
        font-size: var(--font-size-3xl);
    }

    .hero__actions {
        flex-direction: row;
        justify-content: center;
    }

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

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

    .contact-grid {
        grid-template-columns: 3fr 2fr;
    }

    .contact-info {
        order: 0;
    }

    .footer-grid {
        grid-template-columns: 2fr 1fr 1fr;
    }
}

/* ==========================================================================
   Responsive — Desktop (1024px+)
   ========================================================================== */
@media (min-width: 1024px) {
    .nav-toggle-label {
        display: none;
    }

    .main-nav {
        display: block;
        position: static;
        box-shadow: none;
        border-top: none;
    }

    .main-nav ul {
        flex-direction: row;
        align-items: center;
    }

    .main-nav > ul > li > a {
        padding: var(--space-sm) var(--space-md);
        border-bottom: none;
        border-radius: var(--radius-sm);
        font-size: var(--font-size-sm);
    }

    .main-nav > ul > li > a:hover,
    .main-nav > ul > li > a.active {
        background-color: var(--color-gray-50);
    }

    .nav-dropdown {
        position: relative;
    }

    .nav-dropdown-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        min-width: 280px;
        background-color: var(--color-white);
        box-shadow: var(--shadow-md);
        border-radius: var(--radius-md);
        border: 1px solid var(--color-gray-100);
        z-index: 200;
        padding: var(--space-sm) 0;
    }

    .nav-dropdown:hover .nav-dropdown-menu {
        display: block;
    }

    .nav-dropdown-menu a {
        padding: var(--space-sm) var(--space-lg);
        border-bottom: none;
    }

    .nav-dropdown-menu a:hover {
        background-color: var(--color-gray-50);
    }

    .header-cta {
        display: inline-block;
    }

    .features__grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .articles__grid {
        grid-template-columns: repeat(3, 1fr);
    }
}