/* ═══════════════════════════════════════════════════════
   Edward Ayoub, PhD — Premium Academic Portfolio
   ═══════════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=Playfair+Display:ital,wght@0,500;0,600;0,700;1,500&display=swap');

:root {
  /* ── Color Palette ── */
  --bg: #fafafa;
  --bg-alt: #f3f4f6;
  --card: #ffffff;
  --text: #1a1a2e;
  --text-secondary: #4a5568;
  --muted: #718096;
  --accent: #1a365d;
  --accent-light: #2b6cb0;
  --accent-glow: #3182ce;
  --gold: #c9a84c;
  --gold-light: #d4b65c;
  --border: #e8ecf1;
  --border-light: #f0f3f7;
  --hero-bg: #0a192f;
  --hero-bg-2: #112240;
  --hero-text: #e2e8f0;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08), 0 2px 4px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.1), 0 4px 12px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.12), 0 8px 20px rgba(0, 0, 0, 0.06);
  --radius: 12px;
  --radius-lg: 20px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  overflow-x: hidden;
}

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

a {
  color: var(--accent-light);
  text-decoration: none;
  transition: color var(--transition);
}

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

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

/* ═══════════════════════════════════════════════════════
   Navigation
   ═══════════════════════════════════════════════════════ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 0 2rem;
  background: rgba(10, 25, 47, 0.85);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  transition: all var(--transition);
}

.navbar.scrolled {
  background: rgba(10, 25, 47, 0.95);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.2);
}

.navbar-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.nav-brand {
  color: #fff;
  font-weight: 700;
  font-size: 1.1rem;
  text-decoration: none;
  letter-spacing: -0.02em;
  transition: color var(--transition);
  position: relative;
}

.nav-brand::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 24px;
  height: 2px;
  background: var(--gold);
  border-radius: 2px;
}

.nav-brand:hover {
  color: var(--gold);
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 0.25rem;
  align-items: center;
}

.nav-links a {
  color: rgba(255, 255, 255, 0.65);
  text-decoration: none;
  padding: 0.5rem 1rem;
  border-radius: 8px;
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  transition: all var(--transition);
  position: relative;
}

.nav-links a:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.08);
}

.nav-links a.active {
  color: var(--gold);
  background: rgba(201, 168, 76, 0.1);
}

.hamburger {
  display: none;
  background: none;
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: #fff;
  font-size: 1.25rem;
  cursor: pointer;
  padding: 0.4rem 0.6rem;
  border-radius: 8px;
  transition: all var(--transition);
}

.hamburger:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.25);
}

/* ═══════════════════════════════════════════════════════
   Hero Section (Home Page)
   ═══════════════════════════════════════════════════════ */
.hero {
  background: var(--hero-bg);
  color: var(--hero-text);
  text-align: center;
  padding: 10rem 2rem 6rem;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% 0%, rgba(26, 54, 93, 0.5) 0%, transparent 60%),
    radial-gradient(ellipse 60% 50% at 80% 50%, rgba(49, 130, 206, 0.12) 0%, transparent 50%),
    radial-gradient(ellipse 50% 40% at 20% 60%, rgba(201, 168, 76, 0.08) 0%, transparent 50%);
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.015'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  margin: 0 auto;
}

.hero-label {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 1.5rem;
  padding: 0.4rem 1.2rem;
  border: 1px solid rgba(201, 168, 76, 0.3);
  border-radius: 50px;
  background: rgba(201, 168, 76, 0.06);
}

.hero h1 {
  font-family: 'Playfair Display', Georgia, serif;
  font-size: clamp(2.5rem, 5.5vw, 4rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
  color: #fff;
}

.hero .subtitle {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: #94a3b8;
  font-weight: 400;
  line-height: 1.6;
  margin-bottom: 2rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero-links {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 2.5rem;
}

.hero-links a {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  border-radius: 50px;
  font-size: 0.9rem;
  font-weight: 600;
  transition: all var(--transition);
  text-decoration: none;
}

.hero-links .btn-primary {
  background: var(--gold);
  color: var(--hero-bg);
}

.hero-links .btn-primary:hover {
  background: var(--gold-light);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(201, 168, 76, 0.25);
}

.hero-links .btn-outline {
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: #fff;
  background: rgba(255, 255, 255, 0.03);
}

.hero-links .btn-outline:hover {
  border-color: rgba(255, 255, 255, 0.4);
  background: rgba(255, 255, 255, 0.08);
  transform: translateY(-2px);
}

.hero-divider {
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--gold), transparent);
  margin: 0 auto;
  border-radius: 3px;
  position: relative;
  z-index: 1;
}

/* ═══════════════════════════════════════════════════════
   Page Header (Sub-pages)
   ═══════════════════════════════════════════════════════ */
.page-header {
  background: var(--hero-bg);
  color: var(--hero-text);
  text-align: center;
  padding: 8rem 2rem 3.5rem;
  position: relative;
  overflow: hidden;
}

.page-header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% 0%, rgba(26, 54, 93, 0.4) 0%, transparent 60%),
    radial-gradient(ellipse 50% 40% at 80% 60%, rgba(201, 168, 76, 0.06) 0%, transparent 50%);
  pointer-events: none;
}

.page-header h1 {
  font-family: 'Playfair Display', Georgia, serif;
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  position: relative;
  z-index: 1;
}

.page-header .subtitle {
  color: #94a3b8;
  font-size: 1rem;
  margin-top: 0.75rem;
  position: relative;
  z-index: 1;
  font-weight: 400;
}

.page-header .header-line {
  width: 50px;
  height: 3px;
  background: var(--gold);
  margin: 1.5rem auto 0;
  border-radius: 3px;
  position: relative;
  z-index: 1;
}

/* ═══════════════════════════════════════════════════════
   Main Content Container
   ═══════════════════════════════════════════════════════ */
.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 3rem 1.5rem 4rem;
}

/* ═══════════════════════════════════════════════════════
   Section Cards
   ═══════════════════════════════════════════════════════ */
.section-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem 2.25rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
}

.section-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--border-light);
}

.section-card h2 {
  font-family: 'Playfair Display', Georgia, serif;
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  color: var(--accent);
  padding-bottom: 0.75rem;
  border-bottom: none;
  position: relative;
}

.section-card h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 40px;
  height: 3px;
  background: var(--gold);
  border-radius: 3px;
}

.section-card h3 {
  font-size: 1.05rem;
  margin: 1.5rem 0 0.5rem;
  color: var(--text);
  font-weight: 600;
}

.section-card p {
  margin-bottom: 0.75rem;
  color: var(--text-secondary);
  line-height: 1.75;
}

.section-card ul {
  padding-left: 1.5rem;
  margin-bottom: 0.75rem;
}

.section-card li {
  margin-bottom: 0.4rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ═══════════════════════════════════════════════════════
   Scroll Reveal Animations
   ═══════════════════════════════════════════════════════ */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s cubic-bezier(0.4, 0, 0.2, 1),
              transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }

/* ═══════════════════════════════════════════════════════
   Entry / Experience Items
   ═══════════════════════════════════════════════════════ */
.entry {
  margin-bottom: 2rem;
  padding-bottom: 1.75rem;
  border-bottom: 1px solid var(--border-light);
  position: relative;
}

.entry:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.entry-header {
  margin-bottom: 0.5rem;
}

.entry-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.4;
}

.entry-meta {
  font-size: 0.88rem;
  color: var(--muted);
  margin-top: 0.25rem;
  line-height: 1.5;
}

.entry-body {
  margin-top: 0.75rem;
}

.entry-body p {
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

.entry-body ul {
  padding-left: 1.25rem;
}

.entry-body li {
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 0.35rem;
}

/* ═══════════════════════════════════════════════════════
   Significance Blocks
   ═══════════════════════════════════════════════════════ */
.significance {
  background: linear-gradient(135deg, #f8fafc, #f1f5f9);
  border-left: 3px solid var(--gold);
  padding: 1rem 1.25rem;
  border-radius: 0 var(--radius) var(--radius) 0;
  margin-top: 1rem;
}

.significance strong {
  display: block;
  margin-bottom: 0.5rem;
  font-size: 0.85rem;
  color: var(--gold);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  font-weight: 700;
}

.significance ul {
  padding-left: 1.25rem;
  margin: 0;
}

.significance li {
  margin-bottom: 0.3rem;
  font-size: 0.93rem;
  color: var(--text-secondary);
}

/* ═══════════════════════════════════════════════════════
   Publication / Poster Items
   ═══════════════════════════════════════════════════════ */
.pub-item {
  margin-bottom: 1.75rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-light);
  padding-left: 1.25rem;
  position: relative;
}

.pub-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.45rem;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--gold);
}

.pub-item:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.pub-title {
  font-weight: 600;
  font-size: 0.98rem;
  color: var(--text);
  line-height: 1.5;
}

.pub-title a {
  color: var(--accent-light);
  transition: color var(--transition);
}

.pub-title a:hover {
  color: var(--gold);
}

.pub-date {
  font-size: 0.82rem;
  color: var(--muted);
  margin-top: 0.25rem;
  font-weight: 500;
}

.pub-note {
  margin-top: 0.5rem;
  font-size: 0.9rem;
  color: var(--muted);
  font-style: italic;
  line-height: 1.6;
}

/* ═══════════════════════════════════════════════════════
   Fellowship / Award Items
   ═══════════════════════════════════════════════════════ */
.award-item {
  margin-bottom: 1.75rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-light);
}

.award-item:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.award-title {
  font-weight: 700;
  font-size: 1rem;
  color: var(--text);
  line-height: 1.4;
}

.award-amount {
  display: inline-block;
  font-weight: 700;
  color: var(--gold);
  font-size: 0.93rem;
  margin-top: 0.25rem;
}

/* ═══════════════════════════════════════════════════════
   Skills Grid
   ═══════════════════════════════════════════════════════ */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.skills-grid .section-card {
  margin-bottom: 0;
}

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

.skill-list li {
  padding: 0.45rem 0;
  border-bottom: 1px solid var(--border-light);
  font-size: 0.92rem;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.skill-list li::before {
  content: '';
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--gold);
  flex-shrink: 0;
}

.skill-list li:last-child {
  border-bottom: none;
}

/* ═══════════════════════════════════════════════════════
   Highlights Section (Home Page)
   ═══════════════════════════════════════════════════════ */
.highlights {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.25rem;
  margin-top: 1.25rem;
}

.highlight-card {
  background: linear-gradient(135deg, #fafbfc, #f5f7fa);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem 1.25rem;
  text-align: center;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.highlight-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 40px;
  height: 3px;
  background: var(--gold);
  border-radius: 0 0 3px 3px;
}

.highlight-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(201, 168, 76, 0.2);
}

.highlight-card .number {
  font-family: 'Playfair Display', Georgia, serif;
  font-size: 2.75rem;
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
}

.highlight-card .label {
  font-size: 0.85rem;
  color: var(--muted);
  margin-top: 0.5rem;
  font-weight: 500;
  letter-spacing: 0.02em;
}

/* ═══════════════════════════════════════════════════════
   About / Intro Section
   ═══════════════════════════════════════════════════════ */
.intro-section {
  position: relative;
}

.intro-section p {
  font-size: 1.02rem;
  color: var(--text-secondary);
}

.intro-section p:first-of-type::first-line {
  font-weight: 500;
  color: var(--text);
}

/* ═══════════════════════════════════════════════════════
   Footer
   ═══════════════════════════════════════════════════════ */
footer {
  background: var(--hero-bg);
  color: #94a3b8;
  text-align: center;
  padding: 2.5rem 1.5rem;
  font-size: 0.85rem;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  position: relative;
}

footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 40px;
  height: 2px;
  background: var(--gold);
  border-radius: 2px;
}

footer small {
  opacity: 0.8;
}

/* ═══════════════════════════════════════════════════════
   Responsive Design
   ═══════════════════════════════════════════════════════ */
@media (max-width: 768px) {
  .hamburger {
    display: block;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: rgba(10, 25, 47, 0.98);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 1rem 1.5rem 1.5rem;
    box-shadow: 0 16px 40px rgba(0, 0, 0, 0.3);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links a {
    padding: 0.75rem 1rem;
    font-size: 0.95rem;
    border-radius: 8px;
  }

  .hero {
    padding: 8rem 1.5rem 4rem;
  }

  .page-header {
    padding: 7rem 1.5rem 2.5rem;
  }

  .container {
    padding: 2rem 1rem 3rem;
  }

  .section-card {
    padding: 1.5rem;
    border-radius: 10px;
  }

  .highlights {
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
  }

  .highlight-card {
    padding: 1.25rem 0.75rem;
  }

  .highlight-card .number {
    font-size: 2rem;
  }

  .skills-grid {
    grid-template-columns: 1fr;
  }

  .hero-links {
    flex-direction: column;
    align-items: center;
  }

  .hero-links a {
    width: 100%;
    max-width: 260px;
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .navbar {
    padding: 0 1rem;
  }

  .highlights {
    grid-template-columns: 1fr 1fr;
  }

  .section-card {
    padding: 1.25rem;
  }

  .pub-item {
    padding-left: 1rem;
  }
}

/* ═══════════════════════════════════════════════════════
   Print Styles
   ═══════════════════════════════════════════════════════ */
@media print {
  .navbar,
  .hamburger {
    display: none !important;
  }

  .hero,
  .page-header {
    background: #fff !important;
    color: #000 !important;
    padding-top: 2rem !important;
  }

  .hero h1,
  .page-header h1 {
    color: #000 !important;
  }

  .section-card {
    box-shadow: none !important;
    border: 1px solid #ddd !important;
    break-inside: avoid;
  }

  footer {
    background: #fff !important;
    color: #666 !important;
  }
}