/* ==========================================
   CSS VARIABLES
   ========================================== */
:root {
  /* Colors - Dark Theme */
  --color-background: #0a0e27;
  --color-surface: #151a36;
  --color-surface-hover: #1e2545;
  --color-primary: #00a8ff;
  --color-primary-dark: #0088cc;
  --color-accent: #00d4ff;
  --color-text-primary: #ffffff;
  --color-text-secondary: #b8c4d9;
  --color-text-muted: #8896ab;
  --color-border: #2a3554;
  --color-success: #00d977;
  --color-error: #ff4757;

  /* Typography */
  --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  --font-mono: 'SF Mono', Monaco, 'Cascadia Code', monospace;

  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.5rem;
  --font-size-2xl: 2rem;
  --font-size-3xl: 3rem;

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  --spacing-3xl: 6rem;

  /* Layout */
  --container-max-width: 1200px;
  --content-max-width: 800px;
  --header-height: 70px;

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);

  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
}

/* ==========================================
   RESET & BASE STYLES
   ========================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-primary);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--color-text-secondary);
  background-color: var(--color-background);
  overflow-x: hidden;
}

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

h1 {
  font-size: var(--font-size-3xl);
  font-weight: 700;
}

h2 {
  font-size: var(--font-size-2xl);
  font-weight: 600;
}

h3 {
  font-size: var(--font-size-xl);
  font-weight: 600;
}

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

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

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

ul {
  list-style: none;
}

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input, textarea {
  font-family: inherit;
  font-size: inherit;
}

/* ==========================================
   LAYOUT UTILITIES
   ========================================== */
.container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-sm);
}

.section {
  padding: var(--spacing-3xl) 0;
}

.section-title {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
  position: relative;
  display: inline-block;
  left: 50%;
  transform: translateX(-50%);
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 0;
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  border-radius: 2px;
}

/* ==========================================
   NAVIGATION
   ========================================== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  z-index: 1000;
  transition: background-color var(--transition-base), box-shadow var(--transition-base);
}

.header.scrolled {
  background-color: rgba(10, 14, 39, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-md);
}

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

.nav-brand a {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-text-primary);
}

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

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  width: 30px;
  height: 30px;
  z-index: 1001;
}

.hamburger,
.hamburger::before,
.hamburger::after {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--color-text-primary);
  transition: all var(--transition-base);
}

.hamburger {
  position: relative;
}

.hamburger::before,
.hamburger::after {
  content: '';
  position: absolute;
}

.hamburger::before {
  top: -8px;
}

.hamburger::after {
  bottom: -8px;
}

.nav-toggle.active .hamburger {
  background-color: transparent;
}

.nav-toggle.active .hamburger::before {
  top: 0;
  transform: rotate(45deg);
}

.nav-toggle.active .hamburger::after {
  bottom: 0;
  transform: rotate(-45deg);
}

.nav-menu {
  display: flex;
  gap: var(--spacing-lg);
  align-items: center;
}

.nav-link {
  color: var(--color-text-secondary);
  font-weight: 500;
  position: relative;
  padding: var(--spacing-xs) 0;
  transition: color var(--transition-fast);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  transition: width var(--transition-base);
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-text-primary);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

/* ==========================================
   HERO SECTION
   ========================================== */
.hero-section {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--spacing-2xl) var(--spacing-sm);
  background: linear-gradient(135deg, rgba(0, 168, 255, 0.1) 0%, rgba(10, 14, 39, 1) 50%);
  position: relative;
  overflow: hidden;
}

.hero-section::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -50%;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle, rgba(0, 212, 255, 0.1) 0%, transparent 70%);
  animation: float 20s ease-in-out infinite;
}

@keyframes float {
  0%, 100% {
    transform: translate(0, 0) scale(1);
  }
  50% {
    transform: translate(-50px, 50px) scale(1.1);
  }
}

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

.hero-name {
  font-size: clamp(2.5rem, 8vw, 4rem);
  margin-bottom: var(--spacing-sm);
  background: linear-gradient(135deg, var(--color-text-primary), var(--color-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-title {
  font-size: clamp(1.125rem, 3vw, 1.5rem);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xl);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* ==========================================
   BUTTONS
   ========================================== */
.btn {
  display: inline-block;
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--radius-md);
  font-weight: 600;
  text-align: center;
  transition: all var(--transition-base);
  cursor: pointer;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  color: var(--color-text-primary);
  box-shadow: 0 4px 15px rgba(0, 168, 255, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 168, 255, 0.4);
  color: var(--color-text-primary);
}

.btn-primary:active {
  transform: translateY(0);
}

/* ==========================================
   ABOUT SECTION
   ========================================== */
.about-section {
  background-color: var(--color-background);
}

.about-wrapper {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-xl);
  max-width: var(--content-max-width);
  margin: 0 auto;
}

.about-image {
  flex-shrink: 0;
}

.profile-photo {
  width: 250px;
  height: 250px;
  border-radius: 50%;
  object-fit: cover;
  border: 4px solid var(--color-primary);
  box-shadow: 0 8px 24px rgba(0, 168, 255, 0.3);
  transition: all var(--transition-base);
}

.profile-photo:hover {
  transform: scale(1.05);
  box-shadow: 0 12px 32px rgba(0, 168, 255, 0.4);
}

.about-content {
  max-width: var(--content-max-width);
  text-align: center;
}

.about-content p {
  font-size: var(--font-size-lg);
  line-height: 1.8;
  margin-bottom: var(--spacing-md);
}

/* ==========================================
   SKILLS SECTION
   ========================================== */
.skills-section {
  background-color: var(--color-surface);
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-md);
  max-width: 900px;
  margin: 0 auto;
}

.skill-badge {
  background-color: var(--color-background);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  text-align: center;
  transition: all var(--transition-base);
}

.skill-badge h3 {
  font-size: var(--font-size-lg);
  color: var(--color-primary);
  margin: 0;
}

.skill-badge:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
  background-color: var(--color-surface-hover);
}

/* ==========================================
   PROJECTS SECTION
   ========================================== */
.projects-section {
  background-color: var(--color-background);
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-xl);
}

.project-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  transition: all var(--transition-base);
}

.project-card h3 {
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-md);
}

.project-card p {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-md);
  line-height: 1.7;
}

.project-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary);
}

.tech-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
  margin-top: var(--spacing-md);
}

.tag {
  display: inline-block;
  padding: var(--spacing-xs) var(--spacing-sm);
  background-color: rgba(0, 168, 255, 0.15);
  color: var(--color-accent);
  border-radius: var(--radius-sm);
  font-size: var(--font-size-sm);
  font-weight: 500;
  border: 1px solid rgba(0, 168, 255, 0.3);
}

/* ==========================================
   BLOG SECTION
   ========================================== */
.blog-section {
  background-color: var(--color-surface);
}

.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-xl);
}

.blog-card {
  background-color: var(--color-background);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--transition-base);
}

.blog-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary);
}

.blog-image {
  width: 100%;
  height: 200px;
  background: linear-gradient(135deg, var(--color-surface), var(--color-surface-hover));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
}

.blog-image::after {
  content: 'Image Placeholder';
}

.blog-content {
  padding: var(--spacing-lg);
}

.blog-content h3 {
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-sm);
}

.blog-meta {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-sm);
}

.blog-excerpt {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-md);
  line-height: 1.7;
}

.blog-link {
  color: var(--color-primary);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  transition: all var(--transition-fast);
}

.blog-link:hover {
  color: var(--color-accent);
  transform: translateX(5px);
}

/* ==========================================
   CONTACT SECTION
   ========================================== */
.contact-section {
  background-color: var(--color-background);
}

.contact-container {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-2xl);
  max-width: 900px;
  margin: 0 auto;
}

.contact-info p {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
  line-height: 1.8;
}

.social-links {
  display: flex;
  gap: var(--spacing-md);
}

.social-links a {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-md);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  transition: all var(--transition-base);
}

.social-links a:hover {
  background-color: var(--color-surface-hover);
  border-color: var(--color-primary);
  color: var(--color-primary);
  transform: translateY(-2px);
}

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

.contact-form {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
}

.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-group label {
  display: block;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-xs);
  font-weight: 500;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: var(--spacing-sm);
  background-color: var(--color-background);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-primary);
  transition: all var(--transition-base);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(0, 168, 255, 0.1);
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

.form-group.error input,
.form-group.error textarea {
  border-color: var(--color-error);
}

.form-group .error-message {
  display: block;
  color: var(--color-error);
  font-size: var(--font-size-sm);
  margin-top: var(--spacing-xs);
  min-height: 20px;
}

.form-message {
  margin-top: var(--spacing-md);
  padding: var(--spacing-sm);
  border-radius: var(--radius-md);
  text-align: center;
  font-weight: 500;
  display: none;
}

.form-message.success {
  display: block;
  background-color: rgba(0, 217, 119, 0.1);
  color: var(--color-success);
  border: 1px solid var(--color-success);
}

.form-message.error {
  display: block;
  background-color: rgba(255, 71, 87, 0.1);
  color: var(--color-error);
  border: 1px solid var(--color-error);
}

/* ==========================================
   FOOTER
   ========================================== */
.footer {
  background-color: var(--color-surface);
  padding: var(--spacing-xl) 0;
  text-align: center;
  border-top: 1px solid var(--color-border);
}

.footer .container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-sm);
}

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

.footer-links {
  display: flex;
  gap: var(--spacing-md);
}

.footer-links a {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

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

/* ==========================================
   ANIMATIONS
   ========================================== */
.fade-in {
  opacity: 0;
  animation: fadeIn 1s ease forwards;
}

.fade-in:nth-child(1) {
  animation-delay: 0.2s;
}

.fade-in:nth-child(2) {
  animation-delay: 0.4s;
}

.fade-in:nth-child(3) {
  animation-delay: 0.6s;
}

@keyframes fadeIn {
  to {
    opacity: 1;
  }
}

.slide-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.slide-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ==========================================
   RESPONSIVE - MOBILE
   ========================================== */
@media (max-width: 767px) {
  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    position: fixed;
    top: var(--header-height);
    right: -100%;
    width: 70%;
    max-width: 300px;
    height: calc(100vh - var(--header-height));
    background-color: rgba(21, 26, 54, 0.98);
    backdrop-filter: blur(10px);
    flex-direction: column;
    align-items: flex-start;
    padding: var(--spacing-xl);
    gap: var(--spacing-md);
    transition: right var(--transition-base);
    box-shadow: var(--shadow-lg);
  }

  .nav-menu.active {
    right: 0;
  }

  .nav-link {
    width: 100%;
    padding: var(--spacing-sm) 0;
    font-size: var(--font-size-lg);
  }

  .hero-section {
    min-height: calc(100vh - var(--header-height));
    padding-top: var(--header-height);
  }

  .section {
    padding: var(--spacing-2xl) 0;
  }

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

  .projects-grid,
  .blog-grid {
    grid-template-columns: 1fr;
  }

  .contact-container {
    grid-template-columns: 1fr;
  }
}

/* ==========================================
   RESPONSIVE - TABLET
   ========================================== */
@media (min-width: 768px) {
  .container {
    padding: 0 var(--spacing-lg);
  }

  .section {
    padding: var(--spacing-3xl) 0;
  }

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

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

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

  .contact-container {
    grid-template-columns: 1fr 1fr;
    align-items: start;
  }
}

/* ==========================================
   RESPONSIVE - DESKTOP
   ========================================== */
@media (min-width: 1024px) {
  .skills-grid {
    grid-template-columns: repeat(3, 1fr);
  }

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

  .about-wrapper {
    flex-direction: row;
    align-items: flex-start;
    max-width: 1000px;
  }

  .about-content {
    text-align: left;
  }

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

  .hero-title {
    font-size: 1.5rem;
  }
}

/* ==========================================
   ACCESSIBILITY
   ========================================== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
textarea:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}