/* ==========================================================================
   Sebas Duncan Ecom Blog - Stylesheet
   Mobile-first, performance-oriented CSS for SEO
   ========================================================================== */

:root {
  --color-primary: #1e40af;
  --color-primary-dark: #1e3a8a;
  --color-accent: #f59e0b;
  --color-bg: #ffffff;
  --color-bg-alt: #f8fafc;
  --color-text: #0f172a;
  --color-text-muted: #475569;
  --color-border: #e2e8f0;
  --color-success: #059669;
  --max-width: 1100px;
  --content-width: 760px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SF Mono", Monaco, Consolas, monospace;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --radius: 8px;
}

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

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

body {
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

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

/* ===== Header ===== */
.site-header {
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 50;
  box-shadow: var(--shadow-sm);
}

.site-header__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.site-logo {
  font-weight: 800;
  font-size: 1.25rem;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

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

.site-nav ul {
  list-style: none;
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.site-nav a {
  color: var(--color-text-muted);
  font-weight: 500;
  font-size: 0.95rem;
}

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

.cta-button {
  display: inline-block;
  background: var(--color-primary);
  color: #fff !important;
  padding: 0.6rem 1.2rem;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none !important;
  transition: background 0.2s ease, transform 0.2s ease;
}

.cta-button:hover {
  background: var(--color-primary-dark);
  transform: translateY(-1px);
}

.cta-button--accent {
  background: var(--color-accent);
}

.cta-button--accent:hover {
  background: #d97706;
}

/* ===== Layout containers ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.25rem;
}

.container--narrow {
  max-width: var(--content-width);
}

/* ===== Hero ===== */
.hero {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: #fff;
  padding: 4rem 1.25rem 5rem;
  text-align: center;
}

.hero h1 {
  font-size: clamp(1.875rem, 5vw, 2.75rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
  line-height: 1.2;
}

.hero p {
  font-size: clamp(1rem, 2.5vw, 1.2rem);
  opacity: 0.9;
  max-width: 700px;
  margin: 0 auto 1.5rem;
}

/* ===== Breadcrumbs ===== */
.breadcrumbs {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  padding: 1rem 0;
}

.breadcrumbs ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.breadcrumbs li:not(:last-child)::after {
  content: "/";
  margin-left: 0.5rem;
  color: var(--color-border);
}

.breadcrumbs a {
  color: var(--color-text-muted);
}

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

/* ===== Article ===== */
.article-header {
  padding: 2.5rem 0 1.5rem;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 2rem;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin-bottom: 1rem;
}

.article-meta .tag {
  background: var(--color-bg-alt);
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  color: var(--color-primary);
  font-weight: 500;
}

.article-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: 1rem;
  color: var(--color-text);
}

.article-excerpt {
  font-size: 1.15rem;
  color: var(--color-text-muted);
  line-height: 1.6;
  margin-bottom: 1.5rem;
}

.article-author {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem 0;
  font-size: 0.95rem;
}

.author-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 700;
  font-size: 1.1rem;
}

.author-info strong {
  display: block;
  color: var(--color-text);
}

.author-info span {
  color: var(--color-text-muted);
  font-size: 0.85rem;
}

/* ===== Article content ===== */
.article-content {
  font-size: 1.0625rem;
  line-height: 1.75;
}

.article-content h2 {
  font-size: 1.75rem;
  font-weight: 700;
  margin: 2.5rem 0 1rem;
  letter-spacing: -0.01em;
  scroll-margin-top: 80px;
}

.article-content h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin: 2rem 0 0.75rem;
  scroll-margin-top: 80px;
}

.article-content p {
  margin-bottom: 1.25rem;
}

.article-content ul,
.article-content ol {
  margin: 1.25rem 0 1.25rem 1.5rem;
}

.article-content li {
  margin-bottom: 0.5rem;
}

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

.article-content blockquote {
  border-left: 4px solid var(--color-accent);
  background: var(--color-bg-alt);
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
  font-style: italic;
  color: var(--color-text-muted);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.article-content code {
  background: var(--color-bg-alt);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.9em;
  color: var(--color-primary-dark);
}

.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.95rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
}

.article-content th,
.article-content td {
  padding: 0.75rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}

.article-content th {
  background: var(--color-bg-alt);
  font-weight: 700;
  color: var(--color-text);
}

.article-content tr:last-child td {
  border-bottom: none;
}

.article-content tr:hover {
  background: var(--color-bg-alt);
}

/* ===== TOC (Table of Contents) ===== */
.toc {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  margin: 2rem 0;
}

.toc h2 {
  font-size: 1rem !important;
  font-weight: 700 !important;
  margin: 0 0 0.75rem !important;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted) !important;
}

.toc ol {
  margin: 0 0 0 1.25rem;
  padding: 0;
}

.toc li {
  margin-bottom: 0.35rem;
  font-size: 0.95rem;
}

.toc a {
  color: var(--color-text);
  font-weight: 500;
}

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

/* ===== Callout boxes ===== */
.callout {
  background: #fef3c7;
  border-left: 4px solid var(--color-accent);
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
  border-radius: 0 var(--radius) var(--radius) 0;
}

.callout--info {
  background: #dbeafe;
  border-left-color: var(--color-primary);
}

.callout--success {
  background: #d1fae5;
  border-left-color: var(--color-success);
}

.callout strong {
  display: block;
  margin-bottom: 0.25rem;
  color: var(--color-text);
}

/* ===== FAQ ===== */
.faq-section {
  margin: 3rem 0 2rem;
}

.faq-item {
  border-bottom: 1px solid var(--color-border);
  padding: 1rem 0;
}

.faq-item summary {
  font-weight: 700;
  font-size: 1.05rem;
  cursor: pointer;
  color: var(--color-text);
  list-style: none;
  position: relative;
  padding-right: 1.5rem;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 0;
  top: 0;
  font-size: 1.5rem;
  color: var(--color-primary);
  transition: transform 0.2s ease;
}

.faq-item[open] summary::after {
  transform: rotate(45deg);
}

.faq-item div {
  padding-top: 0.75rem;
  color: var(--color-text-muted);
}

/* ===== Card grid (homepage) ===== */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0 3rem;
}

.card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
  display: flex;
  flex-direction: column;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
}

.card__tag {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-primary);
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.card__title {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  line-height: 1.3;
}

.card__title a {
  color: var(--color-text);
}

.card__title a:hover {
  color: var(--color-primary);
  text-decoration: none;
}

.card__excerpt {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  margin-bottom: 1rem;
  flex: 1;
}

.card__meta {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  display: flex;
  gap: 0.75rem;
  align-items: center;
}

/* ===== Section ===== */
.section {
  padding: 3rem 0;
}

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

.section h2 {
  font-size: clamp(1.5rem, 3.5vw, 2rem);
  font-weight: 800;
  letter-spacing: -0.01em;
  margin-bottom: 0.5rem;
}

.section p.lead {
  color: var(--color-text-muted);
  font-size: 1.05rem;
  max-width: 700px;
  margin-bottom: 1.5rem;
}

/* ===== Related articles ===== */
.related {
  margin: 3rem 0 2rem;
  padding: 2rem 0;
  border-top: 1px solid var(--color-border);
}

.related h2 {
  font-size: 1.3rem;
  margin-bottom: 1.25rem;
}

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

.related-grid a {
  display: block;
  padding: 1rem;
  background: var(--color-bg-alt);
  border-radius: var(--radius);
  border: 1px solid transparent;
  color: var(--color-text);
  font-weight: 500;
  transition: all 0.2s ease;
}

.related-grid a:hover {
  border-color: var(--color-primary);
  background: var(--color-bg);
  text-decoration: none;
}

/* ===== CTA banner ===== */
.cta-banner {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: #fff;
  padding: 3rem 1.5rem;
  border-radius: var(--radius);
  text-align: center;
  margin: 3rem 0;
}

.cta-banner h2 {
  color: #fff;
  margin-bottom: 0.5rem;
}

.cta-banner p {
  opacity: 0.9;
  margin-bottom: 1.25rem;
}

.cta-banner .cta-button {
  background: var(--color-accent);
  font-size: 1.05rem;
  padding: 0.75rem 1.75rem;
}

.cta-banner .cta-button:hover {
  background: #d97706;
}

/* ===== Footer ===== */
.site-footer {
  background: var(--color-text);
  color: #cbd5e1;
  padding: 3rem 1.25rem 1.5rem;
  margin-top: 4rem;
}

.site-footer__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid #334155;
}

.site-footer h3 {
  color: #fff;
  font-size: 1rem;
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.site-footer ul {
  list-style: none;
}

.site-footer li {
  margin-bottom: 0.5rem;
  font-size: 0.95rem;
}

.site-footer a {
  color: #cbd5e1;
}

.site-footer a:hover {
  color: #fff;
}

.site-footer p {
  font-size: 0.9rem;
  line-height: 1.6;
}

.site-footer__bottom {
  max-width: var(--max-width);
  margin: 1.5rem auto 0;
  text-align: center;
  font-size: 0.85rem;
  color: #94a3b8;
}

/* ===== Responsive ===== */
@media (max-width: 640px) {
  .site-header__inner {
    padding: 0.75rem 1rem;
  }
  .site-nav ul {
    gap: 1rem;
  }
  .hero {
    padding: 3rem 1rem 3.5rem;
  }
  .article-content {
    font-size: 1rem;
  }
}

/* ===== Print ===== */
@media print {
  .site-header,
  .site-footer,
  .cta-banner,
  .related {
    display: none;
  }
}