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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica,
    Arial, sans-serif;
  color: #333;
  background: #f4f4f4;
  line-height: 1.6;
}

a {
  color: #1a1a2e;
}

.container {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 20px;
}

/* --- Header / Nav --- */

.site-header {
  background: #1a1a2e;
  padding: 16px 0;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-header h1 {
  color: #fff;
  font-size: 20px;
  font-weight: 600;
}

.site-header h1 a {
  color: inherit;
  text-decoration: none;
}

.site-header nav a {
  color: rgba(255, 255, 255, 0.8);
  text-decoration: none;
  margin-left: 20px;
  font-size: 14px;
}

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

/* --- Hero --- */

.hero {
  background: #fff;
  padding: 48px 0;
  text-align: center;
  border-bottom: 1px solid #e0e0e0;
}

.hero h2 {
  font-size: 28px;
  color: #1a1a2e;
  margin-bottom: 12px;
}

.hero p {
  font-size: 17px;
  color: #666;
  max-width: 500px;
  margin: 0 auto 24px;
}

/* --- Signup Form --- */

.signup-form {
  display: flex;
  gap: 8px;
  justify-content: center;
  flex-wrap: wrap;
}

.signup-form input[type="email"] {
  padding: 10px 14px;
  border: 1px solid #ccc;
  border-radius: 4px;
  font-size: 15px;
  width: 280px;
}

.signup-form button {
  padding: 10px 20px;
  background: #1a1a2e;
  color: #fff;
  border: none;
  border-radius: 4px;
  font-size: 15px;
  cursor: pointer;
}

.signup-form button:hover {
  background: #2a2a4e;
}

.signup-message {
  margin-top: 12px;
  font-size: 14px;
  min-height: 20px;
}

.signup-message.success {
  color: #2e7d32;
}

.signup-message.error {
  color: #c62828;
}

/* --- Section --- */

.section {
  padding: 40px 0;
}

.section h2 {
  font-size: 22px;
  color: #1a1a2e;
  margin-bottom: 20px;
}

/* --- Card Grid --- */

.card-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

@media (min-width: 520px) {
  .card-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.card {
  background: #fff;
  border-radius: 6px;
  padding: 20px;
  text-decoration: none;
  color: inherit;
  border: 1px solid #e0e0e0;
  transition: box-shadow 0.15s;
}

.card:hover {
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.card .category {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  color: #fff;
  background: #1a1a2e;
  padding: 2px 8px;
  border-radius: 3px;
  margin-bottom: 8px;
}

.card h3 {
  font-size: 16px;
  margin-bottom: 6px;
  color: #1a1a2e;
}

.card .tagline {
  font-size: 14px;
  color: #666;
  margin-bottom: 8px;
}

.card .date {
  font-size: 12px;
  color: #999;
}

/* --- Report Page --- */

.report-header {
  background: #fff;
  padding: 32px 0;
  border-bottom: 1px solid #e0e0e0;
}

.report-header h2 {
  font-size: 26px;
  color: #1a1a2e;
  margin-bottom: 8px;
}

.report-header .tagline {
  font-size: 17px;
  color: #666;
  font-style: italic;
}

.report-meta {
  margin-top: 12px;
  font-size: 13px;
  color: #999;
}

.report-meta a {
  color: #666;
}

/* --- Tabs --- */

.tabs {
  display: flex;
  gap: 0;
  border-bottom: 2px solid #e0e0e0;
  margin-bottom: 24px;
}

.tab {
  padding: 10px 20px;
  background: none;
  border: none;
  font-size: 15px;
  cursor: pointer;
  color: #666;
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  font-family: inherit;
}

.tab:hover {
  color: #333;
}

.tab.active {
  color: #1a1a2e;
  font-weight: 600;
}

.tab.active[data-level="beginner"] {
  border-bottom-color: #4caf50;
}

.tab.active[data-level="intermediate"] {
  border-bottom-color: #ff9800;
}

.tab.active[data-level="advanced"] {
  border-bottom-color: #f44336;
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
}

.level-content {
  background: #fff;
  padding: 24px;
  border-radius: 6px;
  border: 1px solid #e0e0e0;
  line-height: 1.7;
  font-size: 16px;
}

.level-content.beginner {
  border-left: 4px solid #4caf50;
}

.level-content.intermediate {
  border-left: 4px solid #ff9800;
}

.level-content.advanced {
  border-left: 4px solid #f44336;
}

.why-section,
.takeaways-section {
  background: #fff;
  padding: 24px;
  border-radius: 6px;
  border: 1px solid #e0e0e0;
  margin-bottom: 24px;
  line-height: 1.7;
  font-size: 16px;
}

.why-section h3,
.takeaways-section h3 {
  margin-bottom: 12px;
  font-size: 18px;
  color: #1a1a2e;
}

/* --- Load More --- */

.load-more {
  text-align: center;
  padding: 24px 0;
}

.load-more button {
  padding: 10px 24px;
  background: #fff;
  color: #1a1a2e;
  border: 1px solid #1a1a2e;
  border-radius: 4px;
  font-size: 14px;
  cursor: pointer;
}

.load-more button:hover {
  background: #1a1a2e;
  color: #fff;
}

/* --- Unsubscribe --- */

.unsub-message {
  text-align: center;
  padding: 60px 0;
}

.unsub-message h2 {
  margin-bottom: 12px;
}

/* --- Footer --- */

.site-footer {
  text-align: center;
  padding: 24px 0;
  font-size: 13px;
  color: #999;
}

.site-footer a {
  color: #666;
}

/* --- Markdown rendered content --- */

.level-content p,
.why-section p,
.takeaways-section p {
  margin-bottom: 12px;
}

.level-content code,
.why-section code {
  background: #f0f0f0;
  padding: 2px 5px;
  border-radius: 3px;
  font-size: 14px;
}

.level-content pre {
  background: #f0f0f0;
  padding: 12px;
  border-radius: 4px;
  overflow-x: auto;
  margin-bottom: 12px;
}