/* ========== Modern Premium Design System ========== */
:root {
  /* Sophisticated Color Palette */
  --bg: #ffffff;
  --bg-secondary: #fbfbfd;
  --bg-gradient: linear-gradient(180deg, #ffffff 0%, #f5f5f7 100%);
  --text-primary: #1d1d1f;
  --text-secondary: #6e6e73;
  --text-tertiary: #86868b;
  --accent: #0066cc;
  --accent-hover: #0071e3;
  --border: rgba(0, 0, 0, 0.08);
  --card-bg: rgba(255, 255, 255, 0.8);
  --card-shadow: 0 4px 24px rgba(0, 0, 0, 0.04);
  --card-hover-shadow: 0 20px 40px rgba(0, 0, 0, 0.08);

  /* Reading Progress */
  --progress-height: 4px;
  --progress-bg: rgba(0, 102, 204, 0.1);
  --progress-fill: var(--accent);

  /* Typography */
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-heading: 'EB Garamond', serif;

  /* Spacing & Layout */
  --max-width: 980px;
  --container-padding: 40px;
  --section-spacing: 120px;

  /* Transitions */
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-medium: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  background: var(--bg-gradient);
  color: var(--text-primary);
  font-family: var(--font-body);
  line-height: 1.5;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

ul {
  list-style: none;
}

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

/* ========== Navigation ========== */
.header-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 24px 0;
  margin-bottom: 60px;
}

.site-title {
  font-weight: 600;
  font-size: 1.2rem;
  letter-spacing: -0.02em;
}

.nav-link {
  font-size: 0.95rem;
  color: var(--text-secondary);
  font-weight: 500;
  padding: 8px 16px;
  border-radius: 20px;
}

.nav-link:hover {
  color: var(--text-primary);
  background: var(--bg-secondary);
}

/* ========== Typography ========== */
h1 {
  font-family: var(--font-heading);
  font-size: 4rem;
  font-weight: 500;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: 24px;
}

h2 {
  font-family: var(--font-heading);
  font-size: 2.5rem;
  font-weight: 500;
  line-height: 1.2;
  margin-bottom: 20px;
}

.tagline {
  font-size: 1.5rem;
  color: var(--text-secondary);
  font-weight: 400;
  max-width: 600px;
  margin-bottom: 40px;
}

.intro {
  font-size: 1.25rem;
  color: var(--text-secondary);
  line-height: 1.6;
  max-width: 700px;
  margin-bottom: 80px;
  font-weight: 400;
}

/* ========== Writings List (Grid Layout) ========== */
.writings-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
  margin-bottom: var(--section-spacing);
}

.writing-item {
  position: relative;
  background: var(--card-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-radius: 24px;
  border: 1px solid var(--border);
  transition: var(--transition-medium);
  overflow: hidden;
  height: 100%;
}

.writing-item:hover {
  transform: translateY(-8px);
  box-shadow: var(--card-hover-shadow);
  border-color: transparent;
}

.writing-link {
  display: flex;
  flex-direction: column;
  padding: 40px;
  height: 100%;
  justify-content: space-between;
}

.writing-title {
  font-family: var(--font-heading);
  font-size: 2rem;
  line-height: 1.2;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.writing-excerpt {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 24px;
  flex-grow: 1;
}

.writing-meta {
  font-size: 0.85rem;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
}

/* ========== Reading Progress ========== */
.progress-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--progress-height);
  background: var(--progress-bg);
  z-index: 1000;
}

.progress-bar {
  height: 100%;
  background: var(--progress-fill);
  width: 0%;
  transition: width 0.1s ease-out;
}

/* ========== Article Page Specific ========== */
.article-page {
  animation: fadeInUp 1s cubic-bezier(0.16, 1, 0.3, 1) both;
}

.article-page .site-header {
  text-align: left;
  padding: 0;
  margin-top: 40px;
  margin-bottom: 60px;
}

.article-page h1 {
  font-size: 3.5rem;
  margin-bottom: 16px;
}

.content h2 {
  font-size: 2.2rem;
  margin-top: 60px;
  margin-bottom: 24px;
}

.content p {
  margin-bottom: 28px;
}

.content blockquote {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-style: italic;
  margin: 48px 0;
  padding-left: 32px;
  border-left: 2px solid var(--text-primary);
  color: var(--text-secondary);
}

.back-link {
  display: inline-flex;
  align-items: center;
  color: var(--text-secondary);
  font-weight: 500;
  margin-bottom: 60px;
  font-size: 0.95rem;
}

.back-link:hover {
  color: var(--text-primary);
  transform: translateX(-4px);
}

/* ========== Social Links ========== */
.social-links {
  display: flex;
  gap: 24px;
  margin-top: 32px;
}

.social-link {
  font-size: 1.4rem;
  color: var(--text-secondary);
  transition: var(--transition-fast);
}

.social-link:hover {
  color: var(--text-primary);
  transform: translateY(-2px);
}

/* ========== Footer ========== */
footer {
  padding: 80px 0;
  text-align: center;
  border-top: 1px solid var(--border);
  color: var(--text-tertiary);
  font-size: 0.9rem;
}

footer p {
  margin-top: 24px;
}

/* ========== Animations ========== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.container>* {
  animation: fadeInUp 0.8s cubic-bezier(0.16, 1, 0.3, 1) both;
}

.writings-list .writing-item:nth-child(1) {
  animation-delay: 0.1s;
}

.writings-list .writing-item:nth-child(2) {
  animation-delay: 0.2s;
}

.writings-list .writing-item:nth-child(3) {
  animation-delay: 0.3s;
}

.writings-list .writing-item:nth-child(4) {
  animation-delay: 0.4s;
}

/* ========== Responsive ========== */
@media (max-width: 860px) {
  :root {
    --container-padding: 24px;
  }

  h1 {
    font-size: 3rem;
  }

  h2 {
    font-size: 2rem;
  }

  .writings-list {
    grid-template-columns: 1fr;
  }

  .writing-link {
    padding: 32px;
  }
}

@media (max-width: 480px) {
  h1 {
    font-size: 2.5rem;
  }

  .tagline {
    font-size: 1.25rem;
  }

  .intro {
    font-size: 1.1rem;
  }
}