/*
 * Antonio Narra - antonionarra.io
 * Main Stylesheet
 * Author: Antonio Narra (with Claude collaboration)
 * Colors: Cyan brand (#0891b2, #06b6d4, #0e7490)
 * Mobile-first responsive design
 */

/* ============================================
   CSS VARIABLES (Custom Properties)
   ============================================ */

:root {
  /* Brand Colors (from logo) */
  --color-primary: #0891b2;
  --color-primary-light: #06b6d4;
  --color-primary-dark: #0e7490;

  /* Neutrals */
  --color-background: #ffffff;
  --color-text: #1e293b;
  --color-text-light: #64748b;
  --color-text-muted: #94a3b8;
  --color-border: #e2e8f0;
  --color-background-alt: #f8fafc;

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 3rem;
  --spacing-xl: 4rem;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen",
    "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue",
    sans-serif;
  --font-mono: "Courier New", Courier, monospace;

  /* Transitions */
  --transition-base: all 0.3s ease;
  --transition-fast: all 0.15s ease;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);

  /* Layout */
  --container-width: 1200px;
  --header-height: 70px;
}

/* ============================================
   BASE STYLES
   ============================================ */

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-background);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: var(--transition-base);
}

a:hover {
  color: var(--color-primary-dark);
}

/* ============================================
   TYPOGRAPHY
   ============================================ */

h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-top: 0;
  margin-bottom: var(--spacing-sm);
  color: var(--color-text);
}

h1 {
  font-size: 2.5rem;
}

h2 {
  font-size: 2rem;
}

h3 {
  font-size: 1.5rem;
}

p {
  margin-top: 0;
  margin-bottom: var(--spacing-sm);
}

.section-title {
  text-align: center;
  font-size: 2.5rem;
  margin-bottom: var(--spacing-lg);
  color: var(--color-text);
}

.section-intro {
  text-align: center;
  font-size: 1.125rem;
  color: var(--color-text-light);
  max-width: 700px;
  margin: 0 auto var(--spacing-lg);
}

/* ============================================
   LAYOUT & CONTAINERS
   ============================================ */

.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--spacing-sm);
}

section {
  padding: var(--spacing-xl) 0;
}

/* ============================================
   HEADER & NAVIGATION
   ============================================ */

.site-header {
  position: sticky;
  top: 0;
  background-color: var(--color-background);
  box-shadow: var(--shadow-sm);
  z-index: 1000;
  height: var(--header-height);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
}

.logo img {
  width: 50px;
  height: 50px;
  transition: var(--transition-base);
}

.logo:hover img {
  transform: scale(1.05);
}

.logo:hover {
  color: var(--color-primary);
}

/* Navigation */
.main-nav ul {
  display: flex;
  gap: var(--spacing-md);
  list-style: none;
  margin: 0;
  padding: 0;
}

.main-nav a {
  color: var(--color-text);
  font-weight: 500;
  padding: 0.5rem 1rem;
  border-radius: 0.375rem;
  transition: var(--transition-fast);
}

.main-nav a:hover,
.main-nav a.active {
  color: var(--color-primary);
  background-color: var(--color-background-alt);
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.mobile-menu-toggle span {
  width: 25px;
  height: 3px;
  background-color: var(--color-text);
  transition: var(--transition-fast);
}

/* ============================================
   HERO SECTION
   ============================================ */

.hero {
  background: linear-gradient(
    135deg,
    var(--color-primary-dark) 0%,
    var(--color-primary) 100%
  );
  color: white;
  padding: var(--spacing-xl) 0;
  text-align: center;
}

.hero-content {
  max-width: 900px;
  margin: 0 auto;
}

.hero-title {
  font-size: 3rem;
  margin-bottom: var(--spacing-md);
  line-height: 1.1;
}

.hero-title .highlight {
  color: var(--color-primary-light);
  display: block;
}

.hero-subtitle {
  font-size: 1.25rem;
  line-height: 1.8;
  margin-bottom: var(--spacing-lg);
  opacity: 0.95;
}

.hero-subtitle strong {
  color: var(--color-primary-light);
  font-weight: 600;
}

.hero-cta {
  display: flex;
  gap: var(--spacing-sm);
  justify-content: center;
  flex-wrap: wrap;
}

/* ============================================
   BUTTONS
   ============================================ */

.btn {
  display: inline-block;
  padding: 0.875rem 2rem;
  font-size: 1rem;
  font-weight: 600;
  text-align: center;
  border-radius: 0.5rem;
  transition: var(--transition-base);
  cursor: pointer;
  border: 2px solid transparent;
}

.btn-primary {
  background-color: white;
  color: var(--color-primary);
  border-color: white;
}

.btn-primary:hover {
  background-color: var(--color-background-alt);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background-color: transparent;
  color: white;
  border-color: white;
}

.btn-secondary:hover {
  background-color: rgba(255, 255, 255, 0.1);
  transform: translateY(-2px);
}

.btn-outline {
  background-color: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-outline:hover {
  background-color: var(--color-primary);
  color: white;
}

.btn-large {
  padding: 1rem 2.5rem;
  font-size: 1.125rem;
}

/* ============================================
   TECH STACK SECTION
   ============================================ */

.tech-stack {
  background-color: var(--color-background-alt);
}

.tech-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-md);
}

.tech-category h3 {
  color: var(--color-primary);
  margin-bottom: var(--spacing-sm);
  font-size: 1.25rem;
}

.tech-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.badge {
  display: inline-block;
  padding: 0.5rem 1rem;
  background-color: white;
  color: var(--color-text);
  border-radius: 0.375rem;
  font-size: 0.875rem;
  font-weight: 500;
  box-shadow: var(--shadow-sm);
  transition: var(--transition-fast);
}

.badge:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  color: var(--color-primary);
}

/* ============================================
   TIMELINE / EXPERIENCE
   ============================================ */

.experience-highlights {
  background-color: white;
}

.timeline {
  max-width: 800px;
  margin: 0 auto;
  position: relative;
  padding-left: var(--spacing-md);
}

.timeline::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: linear-gradient(
    to bottom,
    var(--color-primary),
    var(--color-primary-light)
  );
}

.timeline-item {
  position: relative;
  margin-bottom: var(--spacing-lg);
  padding-left: var(--spacing-md);
}

.timeline-item::before {
  content: "";
  position: absolute;
  left: -22px;
  top: 5px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background-color: var(--color-primary);
  border: 3px solid white;
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

.timeline-year {
  display: inline-block;
  background-color: var(--color-primary);
  color: white;
  padding: 0.25rem 0.75rem;
  border-radius: 0.25rem;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.timeline-content h3 {
  color: var(--color-text);
  margin-bottom: 0.5rem;
}

.timeline-content p {
  color: var(--color-text-light);
  margin-bottom: var(--spacing-sm);
}

.tech-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tech-tags span {
  padding: 0.25rem 0.75rem;
  background-color: var(--color-background-alt);
  color: var(--color-primary);
  border-radius: 0.25rem;
  font-size: 0.75rem;
  font-weight: 500;
}

.cta-center {
  text-align: center;
  margin-top: var(--spacing-lg);
}

/* ============================================
   COURSES PREVIEW
   ============================================ */

.courses-preview {
  background-color: var(--color-background-alt);
}

.courses-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-md);
  max-width: 1000px;
  margin: 0 auto;
}

.course-card {
  background-color: white;
  padding: var(--spacing-md);
  border-radius: 0.75rem;
  box-shadow: var(--shadow-md);
  transition: var(--transition-base);
}

.course-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.course-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: var(--spacing-sm);
}

.course-header h3 {
  color: var(--color-text);
  margin: 0;
}

.course-badge {
  background-color: var(--color-primary-light);
  color: white;
  padding: 0.25rem 0.75rem;
  border-radius: 0.25rem;
  font-size: 0.75rem;
  font-weight: 600;
  white-space: nowrap;
}

.course-description {
  color: var(--color-text-light);
  margin-bottom: var(--spacing-sm);
}

.course-highlights {
  list-style: none;
  padding: 0;
  margin: 0 0 var(--spacing-sm);
}

.course-highlights li {
  padding: 0.5rem 0;
  color: var(--color-text-light);
  position: relative;
  padding-left: 1.5rem;
}

.course-highlights li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: bold;
}

/* ============================================
   PHILOSOPHY SECTION
   ============================================ */

.philosophy {
  background-color: white;
}

.philosophy-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-md);
  max-width: 1000px;
  margin: 0 auto;
}

.philosophy-item {
  text-align: center;
  padding: var(--spacing-md);
}

.philosophy-icon {
  font-size: 3rem;
  margin-bottom: var(--spacing-sm);
}

.philosophy-item h3 {
  color: var(--color-text);
  margin-bottom: var(--spacing-sm);
}

.philosophy-item p {
  color: var(--color-text-light);
}

/* ============================================
   CTA SECTION
   ============================================ */

.cta-section {
  background: linear-gradient(
    135deg,
    var(--color-primary-dark) 0%,
    var(--color-primary) 100%
  );
  color: white;
  text-align: center;
}

.cta-section h2 {
  color: white;
  font-size: 2.5rem;
  margin-bottom: var(--spacing-sm);
}

.cta-section p {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-lg);
  opacity: 0.95;
}

.cta-buttons {
  display: flex;
  gap: var(--spacing-sm);
  justify-content: center;
  flex-wrap: wrap;
}

/* ============================================
   FOOTER
   ============================================ */

.site-footer {
  background-color: var(--color-text);
  color: white;
  padding: var(--spacing-xl) 0 var(--spacing-md);
}

.footer-content {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.footer-brand img {
  width: 40px;
  height: 40px;
}

.footer-brand p {
  color: var(--color-text-muted);
  margin: 0;
}

.footer-links h4,
.footer-social h4 {
  color: white;
  margin-bottom: var(--spacing-sm);
  font-size: 1rem;
}

.footer-links ul,
.social-links {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-links li,
.social-links li {
  margin-bottom: 0.5rem;
}

.footer-links a,
.social-links a {
  color: var(--color-text-muted);
  transition: var(--transition-fast);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.footer-links a:hover,
.social-links a:hover {
  color: var(--color-primary-light);
}

.social-links svg {
  width: 20px;
  height: 20px;
}

.github-coming-soon .disabled {
  color: var(--color-text-light);
  cursor: not-allowed;
  opacity: 0.5;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--spacing-md);
  text-align: center;
  color: var(--color-text-muted);
}

.footer-bottom p {
  margin-bottom: 0.5rem;
}

.footer-bottom a {
  color: var(--color-primary-light);
}

/* ============================================
   RESPONSIVE - TABLET (768px+)
   ============================================ */

@media (min-width: 768px) {
  .container {
    padding: 0 var(--spacing-md);
  }

  h1 {
    font-size: 3rem;
  }

  .section-title {
    font-size: 3rem;
  }

  .hero-title {
    font-size: 3.5rem;
  }

  .tech-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .courses-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .philosophy-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-content {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ============================================
   RESPONSIVE - DESKTOP (1024px+)
   ============================================ */

@media (min-width: 1024px) {
  section {
    padding: 5rem 0;
  }

  .hero {
    padding: 5rem 0;
  }

  .hero-title {
    font-size: 4rem;
  }

  .tech-grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .philosophy-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

/* ============================================
   RESPONSIVE - MOBILE (max 767px)
   ============================================ */

@media (max-width: 767px) {
  .main-nav {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background-color: white;
    box-shadow: var(--shadow-lg);
    padding: var(--spacing-sm);
  }

  .main-nav.active {
    display: block;
  }

  .main-nav ul {
    flex-direction: column;
    gap: 0;
  }

  .main-nav a {
    display: block;
    padding: var(--spacing-sm);
  }

  .mobile-menu-toggle {
    display: flex;
  }

  .hero-title {
    font-size: 2rem;
  }

  .section-title {
    font-size: 2rem;
  }
}

/* ============================================
   UTILITIES
   ============================================ */

.text-center {
  text-align: center;
}

.mt-0 {
  margin-top: 0;
}
.mt-1 {
  margin-top: var(--spacing-sm);
}
.mt-2 {
  margin-top: var(--spacing-md);
}
.mt-3 {
  margin-top: var(--spacing-lg);
}

.mb-0 {
  margin-bottom: 0;
}
.mb-1 {
  margin-bottom: var(--spacing-sm);
}
.mb-2 {
  margin-bottom: var(--spacing-md);
}
.mb-3 {
  margin-bottom: var(--spacing-lg);
}