/* ============================================================
   THE ASYMMETRICAL EDUCATION — Design System
   Premium Financial Publication Aesthetic
   ============================================================ */

/* ---------- Google Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Playfair+Display:ital,wght@0,400;0,500;0,600;0,700;1,400;1,500&display=swap');

/* ---------- Design Tokens ---------- */
:root {
  --color-bg: #0c0c0c;
  --color-surface: #161616;
  --color-surface-hover: #1e1e1e;
  --color-text: #b0b0b0;
  --color-text-strong: #e8e8e8;
  --color-heading: #f2f0eb;
  --color-accent: #d4a843;
  --color-accent-hover: #e6c366;
  --color-accent-dim: rgba(212, 168, 67, 0.15);
  --color-muted: #5a5a5a;
  --color-border: #252525;
  --color-border-light: #333;

  --font-heading: 'Playfair Display', Georgia, 'Times New Roman', serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

  --max-width-article: 720px;
  --max-width-index: 960px;
  --transition-fast: 0.2s ease;
  --transition-med: 0.35s ease;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.8;
  font-weight: 400;
  min-height: 100vh;
}

::selection {
  background: var(--color-accent);
  color: var(--color-bg);
}

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

/* ---------- Reading Progress Bar ---------- */
.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  width: 0%;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent), var(--color-accent-hover));
  z-index: 1000;
  transition: width 0.1s linear;
}

/* ---------- Navigation ---------- */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(12, 12, 12, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border);
  padding: 0 24px;
}

.site-nav .nav-inner {
  max-width: var(--max-width-index);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.site-nav .nav-logo {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--color-heading);
  text-decoration: none;
  letter-spacing: -0.01em;
  transition: color var(--transition-fast);
}

.site-nav .nav-logo:hover {
  color: var(--color-accent);
}

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

.site-nav .nav-links {
  display: flex;
  gap: 28px;
  list-style: none;
}

.site-nav .nav-links a {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--color-muted);
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  transition: color var(--transition-fast);
}

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

/* ---------- Links ---------- */
a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

/* ---------- Container ---------- */
.container {
  max-width: var(--max-width-article);
  margin: 0 auto;
  padding: 40px 24px 60px;
}

.container--wide {
  max-width: var(--max-width-index);
}

/* ---------- Page Entry Animation ---------- */
.page-enter {
  animation: fadeInUp 0.6s ease both;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ============================================================
   HERO (Index Page)
   ============================================================ */
.hero {
  padding: 80px 0 60px;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 48px;
}

.hero__label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--color-accent);
  margin-bottom: 20px;
  display: block;
}

.hero__title {
  font-family: var(--font-heading);
  font-size: clamp(2.2rem, 5vw, 3.2rem);
  font-weight: 700;
  color: var(--color-heading);
  line-height: 1.15;
  margin-bottom: 20px;
  letter-spacing: -0.02em;
}

.hero__subtitle {
  font-size: 1.15rem;
  color: var(--color-text);
  line-height: 1.7;
  max-width: 600px;
  font-weight: 300;
}

/* ---------- Gemini Explainer Button ---------- */
.explainer-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-top: 28px;
  padding: 12px 24px;
  background: var(--color-accent-dim);
  border: 1px solid rgba(212, 168, 67, 0.3);
  border-radius: 8px;
  color: var(--color-accent);
  font-family: var(--font-body);
  font-size: 0.88rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-med);
}

.explainer-btn:hover {
  background: rgba(212, 168, 67, 0.25);
  border-color: var(--color-accent);
  transform: translateY(-1px);
}

.explainer-btn .loader {
  border: 2px solid rgba(212, 168, 67, 0.3);
  border-top: 2px solid var(--color-accent);
  border-radius: 50%;
  width: 14px;
  height: 14px;
  animation: spin 0.8s linear infinite;
  display: none;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ============================================================
   SECTIONS (Index Page)
   ============================================================ */
.section-label {
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--color-muted);
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--color-border);
}

/* ---------- Featured Post ---------- */
.featured-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-accent);
  border-radius: 8px;
  padding: 32px;
  margin-bottom: 48px;
  transition: all var(--transition-med);
}

.featured-card:hover {
  border-color: var(--color-accent);
  background: var(--color-surface-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.featured-card .card-category {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-accent);
  margin-bottom: 12px;
}

.featured-card .card-title {
  font-family: var(--font-heading);
  font-size: 1.55rem;
  font-weight: 600;
  color: var(--color-heading);
  line-height: 1.3;
  margin-bottom: 12px;
}

.featured-card .card-title a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

.featured-card .card-title a:hover {
  color: var(--color-accent);
}

.featured-card .card-excerpt {
  font-size: 0.95rem;
  color: var(--color-text);
  line-height: 1.7;
  margin-bottom: 16px;
}

.read-more {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--color-accent);
  text-decoration: none;
  letter-spacing: 0.03em;
  transition: all var(--transition-fast);
}

.read-more:hover {
  color: var(--color-accent-hover);
  letter-spacing: 0.06em;
}

/* ---------- Tools Section ---------- */
.tools-section {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 28px 32px;
  margin-bottom: 48px;
}

.tools-section h3 {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  color: var(--color-heading);
  margin: 0 0 16px;
}

.tool-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 12px 0;
}

.tool-item-left {
  display: flex;
  align-items: center;
  gap: 16px;
}

.tool-icon {
  width: 48px;
  height: 48px;
  border-radius: 10px;
  flex-shrink: 0;
  filter: drop-shadow(0 0 6px rgba(212, 168, 67, 0.2));
  transition: filter var(--transition-med), transform var(--transition-med);
}

.tool-item:hover .tool-icon {
  filter: drop-shadow(0 0 12px rgba(212, 168, 67, 0.4));
  transform: scale(1.05);
}

.tool-badge {
  background: var(--color-accent);
  color: var(--color-bg);
  padding: 4px 12px;
  border-radius: 4px;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  white-space: nowrap;
  flex-shrink: 0;
}

/* ---------- Article Grid ---------- */
.article-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--color-border);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  overflow: hidden;
  margin-bottom: 48px;
}

.article-grid .grid-item {
  background: var(--color-surface);
  padding: 24px 28px;
  transition: background var(--transition-fast);
}

.article-grid .grid-item:hover {
  background: var(--color-surface-hover);
}

.article-grid .grid-category {
  font-size: 0.68rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-accent);
  margin-bottom: 6px;
}

.article-grid .grid-title {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--color-heading);
  line-height: 1.35;
  margin-bottom: 8px;
}

.article-grid .grid-title a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

.article-grid .grid-title a:hover {
  color: var(--color-accent);
}

.article-grid .grid-excerpt {
  font-size: 0.88rem;
  color: var(--color-muted);
  line-height: 1.6;
  margin-bottom: 10px;
}

/* ============================================================
   ARTICLE PAGE TYPOGRAPHY
   ============================================================ */

/* ---------- Article Header ---------- */
.article-header {
  padding: 60px 0 40px;
  margin-bottom: 40px;
  border-bottom: 1px solid var(--color-border);
}

.article-header .back-link {
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--color-muted);
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  transition: color var(--transition-fast);
  display: inline-block;
  margin-bottom: 24px;
}

.article-header .back-link:hover {
  color: var(--color-accent);
}

.article-header h1 {
  font-family: var(--font-heading);
  font-size: clamp(1.8rem, 4.5vw, 2.6rem);
  font-weight: 700;
  color: var(--color-heading);
  line-height: 1.2;
  letter-spacing: -0.02em;
  border-left: 4px solid var(--color-accent);
  padding-left: 20px;
  margin: 0;
}

/* ---------- Article Body ---------- */
.article-content h2 {
  font-family: var(--font-heading);
  font-size: 1.55rem;
  font-weight: 600;
  color: var(--color-heading);
  margin-top: 48px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
  line-height: 1.3;
}

.article-content h3 {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  font-weight: 500;
  color: var(--color-text-strong);
  margin-top: 36px;
  margin-bottom: 12px;
  font-style: italic;
}

.article-content p {
  margin-bottom: 22px;
  font-size: 1.05rem;
  line-height: 1.85;
}

.article-content strong {
  color: var(--color-text-strong);
  font-weight: 600;
}

/* Drop Cap */
.article-content > p:first-of-type::first-letter {
  font-family: var(--font-heading);
  font-size: 3.5em;
  float: left;
  line-height: 0.8;
  padding-right: 10px;
  padding-top: 6px;
  color: var(--color-accent);
  font-weight: 700;
}

/* ---------- Blockquotes ---------- */
.article-content blockquote {
  margin: 32px 0;
  padding: 24px 28px;
  background: var(--color-surface);
  border-left: 4px solid var(--color-accent);
  border-radius: 0 8px 8px 0;
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-style: italic;
  color: var(--color-text-strong);
  line-height: 1.6;
}

.article-content blockquote p {
  margin: 0;
}

/* ---------- Lists ---------- */
.article-content ul,
.article-content ol {
  margin: 20px 0;
  padding-left: 24px;
}

.article-content ul li,
.article-content ol li {
  margin-bottom: 12px;
  padding-left: 8px;
  line-height: 1.7;
}

.article-content ol li {
  padding-left: 4px;
}

/* ---------- Tables ---------- */
.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 32px 0;
  font-size: 0.92rem;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  overflow: hidden;
}

.article-content th,
.article-content td {
  padding: 14px 18px;
  text-align: left;
  border: 1px solid var(--color-border);
}

.article-content th {
  background: var(--color-surface);
  color: var(--color-accent);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-size: 0.8rem;
}

.article-content td {
  background: var(--color-bg);
}

.article-content tr:hover td {
  background: var(--color-surface);
}

/* ============================================================
   AUTHOR BIO (End of Article)
   ============================================================ */
.author-bio {
  margin-top: 56px;
  padding-top: 32px;
  border-top: 1px solid var(--color-border);
}

.author-bio .bio-label {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-accent);
  margin-bottom: 8px;
}

.author-bio p {
  font-size: 0.9rem;
  color: var(--color-muted);
  line-height: 1.7;
}

/* ============================================================
   AUTHOR PAGE
   ============================================================ */
.author-content {
  display: flex;
  flex-wrap: wrap;
  gap: 36px;
  margin-bottom: 40px;
}

.author-image {
  flex: 0 0 180px;
}

.author-image svg {
  width: 100%;
  height: auto;
  border-radius: 8px;
  border: 2px solid var(--color-border);
}

.author-bio-full {
  flex: 1;
  min-width: 280px;
}

.author-bio-full p {
  margin-bottom: 18px;
  font-size: 1rem;
  line-height: 1.8;
}

.credentials-list {
  list-style: none;
  padding: 0;
}

.credentials-list li {
  margin-bottom: 14px;
  padding-left: 28px;
  position: relative;
  line-height: 1.6;
}

.credentials-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--color-accent);
  font-weight: 700;
}

.credentials-list strong {
  color: var(--color-text-strong);
}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 32px 24px;
  margin-top: 64px;
  text-align: center;
}

.site-footer .footer-inner {
  max-width: var(--max-width-index);
  margin: 0 auto;
}

.site-footer p {
  font-size: 0.78rem;
  color: var(--color-muted);
  margin-bottom: 6px;
  line-height: 1.6;
}

.site-footer .footer-links {
  margin-top: 12px;
  display: flex;
  justify-content: center;
  gap: 24px;
}

.site-footer .footer-links a {
  font-size: 0.78rem;
  color: var(--color-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

/* ============================================================
   MODAL (Gemini Explainer)
   ============================================================ */
.modal {
  position: fixed;
  inset: 0;
  z-index: 200;
  overflow-y: auto;
  background-color: rgba(0, 0, 0, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  opacity: 0;
  transition: opacity 0.3s ease;
  visibility: hidden;
}

.modal.is-open {
  opacity: 1;
  visibility: visible;
}

.modal-content {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  color: var(--color-text);
  border-radius: 12px;
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.5);
  width: 100%;
  max-width: 480px;
  transform: scale(0.95);
  opacity: 0;
  transition: all 0.3s ease;
}

.modal.is-open .modal-content {
  transform: scale(1);
  opacity: 1;
}

.modal-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-header h3 {
  margin: 0;
  font-family: var(--font-heading);
  font-size: 1.15rem;
  color: var(--color-heading);
  font-weight: 600;
}

.modal-close {
  background: none;
  border: none;
  color: var(--color-muted);
  font-size: 1.5rem;
  line-height: 1;
  cursor: pointer;
  padding: 0;
  transition: color var(--transition-fast);
}

.modal-close:hover {
  color: var(--color-text);
}

.modal-body {
  padding: 24px;
}

.modal-body p {
  font-size: 1rem;
  margin: 0;
  line-height: 1.7;
}

.modal-footer {
  padding: 16px 24px;
  background: var(--color-bg);
  border-top: 1px solid var(--color-border);
  border-radius: 0 0 12px 12px;
  text-align: right;
}

.modal-footer button {
  background: var(--color-accent);
  color: var(--color-bg);
  border: none;
  padding: 10px 20px;
  border-radius: 6px;
  font-weight: 600;
  font-family: var(--font-body);
  font-size: 0.88rem;
  cursor: pointer;
  transition: background var(--transition-fast);
}

.modal-footer button:hover {
  background: var(--color-accent-hover);
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 768px) {
  body {
    font-size: 16px;
  }

  .site-nav .nav-links {
    gap: 16px;
  }

  .site-nav .nav-links a {
    font-size: 0.75rem;
  }

  .hero {
    padding: 48px 0 40px;
  }

  .hero__title {
    font-size: 2rem;
  }

  .article-header h1 {
    font-size: 1.7rem;
  }

  .featured-card {
    padding: 24px;
  }

  .container {
    padding: 24px 16px 48px;
  }

  .author-content {
    flex-direction: column;
  }

  .author-image {
    flex: none;
    width: 140px;
  }
}

@media (max-width: 480px) {
  .site-nav .nav-links {
    gap: 12px;
  }

  .hero__title {
    font-size: 1.7rem;
  }

  .featured-card .card-title {
    font-size: 1.25rem;
  }

  .article-grid .grid-item {
    padding: 20px;
  }
}