/* ==========================================================================
   RAJ PRABHAKARAN — PERSONAL PORTFOLIO & WRITING
   Clean, Editorial & Light Theme Design System
   ========================================================================== */

:root {
  /* Color Palette - Light, crisp & warm editorial neutrals */
  --bg-page: #faf9f6;
  --bg-surface: #ffffff;
  --bg-subtle: #f4f3ef;
  --bg-card-hover: #fcfcfb;
  
  --text-primary: #18181b;
  --text-secondary: #4b5563;
  --text-muted: #6b7280;
  --text-subtle: #9ca3af;
  
  --accent-primary: #1d4ed8;
  --accent-hover: #1e40af;
  --accent-light: #eff6ff;
  --accent-border: #bfdbfe;
  
  --border-light: #e5e7eb;
  --border-subtle: #f3f4f6;
  --border-focus: #93c5fd;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.03);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.04), 0 4px 6px -4px rgba(0, 0, 0, 0.02);
  --shadow-card: 0 1px 3px 0 rgba(0, 0, 0, 0.04), 0 1px 2px -1px rgba(0, 0, 0, 0.03);

  /* Fluid Spacing Scale */
  --space-2xs: 4px;
  --space-xs: 8px;
  --space-sm: 16px;
  --space-md: 24px;
  --space-lg: 32px;
  --space-xl: 48px;
  --space-2xl: 64px;
  --space-3xl: 96px;

  /* Layout */
  --container-width: 720px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: var(--bg-page);
  color: var(--text-secondary);
  font-family: var(--font-sans);
  line-height: 1.75;
  font-size: 1.0625rem;
  letter-spacing: -0.011em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Base Links & Typography */
a {
  color: inherit;
  text-decoration: none;
  transition: color 0.15s ease, border-color 0.15s ease;
}

strong {
  color: var(--text-primary);
  font-weight: 600;
}

/* Main Container Layout */
.site-wrapper {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: var(--space-xl) var(--space-md) var(--space-3xl);
  flex: 1;
}

/* ==========================================================================
   HEADER & NAVIGATION
   ========================================================================== */
.site-header {
  display: flex;
  justify-content: center;
  align-items: center;
  padding-bottom: var(--space-sm);
  margin-bottom: var(--space-lg);
  border-bottom: 1px solid var(--border-light);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.nav-item {
  font-size: 0.9rem;
  color: var(--text-muted);
  font-weight: 500;
  padding: var(--space-2xs) 0;
  position: relative;
}

.nav-item:hover {
  color: var(--text-primary);
}

.nav-item.active {
  color: var(--text-primary);
  font-weight: 600;
}

/* ==========================================================================
   AUTHOR PROFILE / HERO
   ========================================================================== */
.hero-intro-card {
  display: flex;
  align-items: flex-start;
  gap: var(--space-lg);
  margin-bottom: var(--space-xl);
  padding: var(--space-lg);
  background-color: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.hero-portrait-frame {
  flex-shrink: 0;
  width: 140px;
  height: 155px;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
  border: 1px solid var(--border-light);
  background-color: var(--bg-subtle);
}

.hero-portrait-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center top;
  display: block;
  transition: transform 0.3s ease;
}

.hero-intro-card:hover .hero-portrait-img {
  transform: scale(1.03);
}

.hero-intro-text {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.hero-greeting {
  font-size: 1.15rem;
  color: var(--text-secondary);
  line-height: 1.4;
  margin: 0;
}

.hero-greeting strong {
  color: var(--text-primary);
  font-weight: 700;
}

.hero-title {
  font-size: clamp(1.25rem, 3vw, 1.6rem);
  line-height: 1.3;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.025em;
  margin: 4px 0 6px 0;
}

.hero-question {
  font-size: 0.96rem;
  color: var(--text-muted);
  line-height: 1.55;
  margin: 0;
}

.hero-question strong {
  color: var(--text-secondary);
}

/* ==========================================================================
   STORY / BIO CONTENT
   ========================================================================== */
.bio-content {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  margin-bottom: var(--space-2xl);
}

.bio-paragraph {
  font-size: 1.08rem;
  line-height: 1.8;
  color: var(--text-secondary);
}

.bio-paragraph.highlight {
  font-size: 1.15rem;
  color: var(--text-primary);
  line-height: 1.6;
  border-left: none;
  padding-left: 0;
}

/* ==========================================================================
   PROJECTS SECTION & CARDS
   ========================================================================== */
.projects-section {
  margin-top: var(--space-xl);
  margin-bottom: var(--space-2xl);
}

.section-intro {
  margin-bottom: var(--space-md);
}

.section-heading {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  margin-bottom: 6px;
}

.section-subheading {
  font-size: 0.96rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin: 0;
}

.projects-grid {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.project-card {
  display: block;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: var(--space-md) var(--space-lg);
  box-shadow: var(--shadow-card);
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  overflow: hidden;
  text-decoration: none;
}

.project-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background-color: var(--accent-primary);
  opacity: 0;
  transition: opacity 0.2s ease;
}

.project-card:hover {
  border-color: var(--accent-border);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  background-color: var(--bg-card-hover);
}

.project-card:hover::before {
  opacity: 1;
}

.project-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.project-card-title-group {
  display: flex;
  align-items: center;
  gap: 10px;
}

.project-status-dot {
  width: 8px;
  height: 8px;
  border-radius: var(--radius-full);
  background-color: #10b981;
  flex-shrink: 0;
}

.project-card-title {
  font-size: 1.12rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.015em;
  margin: 0;
  transition: color 0.15s ease;
}

.project-card:hover .project-card-title {
  color: var(--accent-primary);
}

.arrow-icon {
  display: inline-block;
  color: var(--text-muted);
  font-size: 1.1rem;
  transition: transform 0.2s ease, color 0.15s ease;
}

.project-card:hover .arrow-icon {
  transform: translateX(4px);
  color: var(--accent-primary);
}

.project-card-desc {
  font-size: 0.93rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin: 0 0 var(--space-sm) 0;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
  padding-top: 10px;
  border-top: 1px solid var(--border-subtle);
}

.project-tag {
  display: inline-flex;
  align-items: center;
  background-color: var(--bg-subtle);
  color: var(--text-muted);
  font-size: 0.78rem;
  font-weight: 500;
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-light);
}

.project-badge-writing {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--accent-primary);
  background-color: var(--accent-light);
  padding: 2px 7px;
  border-radius: 4px;
  letter-spacing: 0.05em;
  flex-shrink: 0;
}

/* ==========================================================================
   FOOTER
   ========================================================================== */
.site-footer {
  margin-top: auto;
  padding-top: var(--space-xl);
  border-top: 1px solid var(--border-light);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-sm);
  font-size: 0.875rem;
  color: var(--text-muted);
}

.footer-links {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.footer-link {
  color: var(--text-muted);
  font-weight: 500;
  text-decoration: none;
  font-size: 0.88rem;
}

.footer-link:hover {
  color: var(--text-primary);
}

/* Email Copy Button */
.email-copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background-color: var(--bg-subtle);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 4px 10px;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  color: var(--text-primary);
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s ease;
}

.email-copy-btn:hover {
  background-color: var(--accent-light);
  border-color: var(--accent-border);
  color: var(--accent-primary);
}

.copy-icon-wrap {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  transition: all 0.15s ease;
}

.copy-svg {
  display: block;
}

.check-svg {
  display: none;
}

.email-copy-btn:hover .copy-icon-wrap {
  color: var(--accent-primary);
}

.email-copy-btn.copied {
  background-color: #f0fdf4;
  border-color: #86efac;
  color: #15803d;
}

.email-copy-btn.copied .copy-svg {
  display: none;
}

.email-copy-btn.copied .check-svg {
  display: block;
}

/* ==========================================================================
   MOBILE RESPONSIVENESS (< 640px)
   ========================================================================== */
@media (max-width: 640px) {
  .site-wrapper {
    padding: 16px 20px 60px;
  }

  .site-header {
    padding-bottom: var(--space-md);
    margin-bottom: var(--space-md);
  }

  .hero-intro-card {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-sm);
    padding: var(--space-md);
  }

  .hero-portrait-frame {
    width: 115px;
    height: 128px;
  }

  .hero-title {
    font-size: 1.6rem;
    line-height: 1.25;
    margin-bottom: var(--space-md);
  }

  .bio-paragraph {
    font-size: 1rem;
    line-height: 1.7;
  }

  .bio-paragraph.highlight {
    font-size: 1.05rem;
  }

  .project-callout-card {
    padding: var(--space-md);
  }

  .site-footer {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-xs);
  }
}