/* ========================================
   CSS VARIABLES & DESIGN SYSTEM
   ======================================== */
:root {
  /* Color Palette */
  --color-primary: #1a3d63;
  --color-primary-dark: #0a1931;
  --color-primary-light: #2d5a8a;
  --color-accent: #4a90e2;
  --color-accent-hover: #357abd;
  
  --color-bg-light: #f8f9fa;
  --color-bg-white: #ffffff;
  --color-bg-dark: #0b1a30;
  --color-bg-card: #0b1a30;
  
  --color-text-primary: #ffffff;
  --color-text-secondary: #e0e0e0;
  --color-text-dark: #333333;
  --color-text-muted: #6c757d;
  
  /* Typography */
  --font-primary: "Open Sans", sans-serif;
  --font-secondary: "Roboto", sans-serif;
  
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  
  /* Borders & Shadows */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-full: 9999px;
  
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.15);
  --shadow-lg: 0 10px 20px rgba(0, 0, 0, 0.2);
  --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.3);
  
  /* Transitions */
  --transition-fast: 0.15s ease-in-out;
  --transition-base: 0.3s ease-in-out;
  --transition-slow: 0.5s ease-in-out;
  
  /* Layout */
  --container-max-width: 1200px;
  --header-height: 70px;
}

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

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

body {
  font-family: var(--font-primary);
  line-height: 1.6;
  color: var(--color-text-dark);
  background-color: var(--color-bg-light);
  overflow-x: hidden;
}

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

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  transition: all var(--transition-base);
}

/* ========================================
   HEADER & NAVIGATION
   ======================================== */
.header-container {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  padding: var(--spacing-md) var(--spacing-xl);
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: var(--shadow-md);
  animation: slideDown 0.5s ease-out;
}

@keyframes slideDown {
  from {
    transform: translateY(-100%);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

.logo {
  width: 45px;
  height: 45px;
  transition: transform var(--transition-base);
}

.logo:hover {
  transform: scale(1.1) rotate(5deg);
}

.navbar {
  display: flex;
  gap: var(--spacing-sm);
  transition: 0.3s;
}

.navbar ul {
  list-style: none;
  display: flex;
  gap: var(--spacing-sm);
  align-items: center;
}

/* Mobile menu active state */
#nav-menu.active {
  display: flex !important;
}

.navbar a {
  color: var(--color-text-primary);
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--radius-full);
  font-weight: 500;
  position: relative;
  display: inline-block;
  transition: all var(--transition-base);
}

.navbar a::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  width: 100%;
  height: 100%;
  background-color: var(--color-primary-dark);
  border-radius: var(--radius-full);
  transform: scale(0);
  opacity: 0;
  transition: transform var(--transition-base), opacity var(--transition-base);
  z-index: -1;
}

.navbar a:hover::before {
  transform: scale(1);
  opacity: 1;
}

.navbar a:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

/* Mobile Navigation Toggle */
.mobile-nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--color-text-primary);
  font-size: var(--font-size-2xl);
  cursor: pointer;
}

/* Close button inside mobile menu */
.mobile-menu-close {
  display: none;
  position: absolute;
  top: var(--spacing-lg);
  right: var(--spacing-lg);
  background: rgba(255, 255, 255, 0.1);
  border: 2px solid rgba(255, 255, 255, 0.3);
  color: var(--color-text-primary);
  font-size: var(--font-size-2xl);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  cursor: pointer;
  transition: all var(--transition-base);
  z-index: 10;
}

.mobile-menu-close:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: rotate(90deg);
}

@media (max-width: 768px) {
  .mobile-menu-close {
    display: flex;
    align-items: center;
    justify-content: center;
  }
}

/* ========================================
   MOBILE RESPONSIVE NAVIGATION (SIDEBAR)
   ======================================== */
@media (max-width: 768px) {
  .mobile-nav-toggle {
    display: block;
    z-index: 1001;
    position: relative;
  }
  
  .navbar {
    position: fixed;
    top: 0;
    right: -100%;
    height: 100vh;
    width: 280px;
    background: linear-gradient(135deg, rgba(26, 61, 99, 0.98) 0%, rgba(10, 25, 49, 0.98) 100%);
    backdrop-filter: blur(10px);
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    justify-content: flex-start;
    padding-top: var(--spacing-3xl);
    transition: right 0.3s ease;
    z-index: 1000;
    box-shadow: -5px 0 15px rgba(0, 0, 0, 0.3);
  }
  
  .navbar.active {
    right: 0;
  }
  
  .navbar ul {
    flex-direction: column;
    gap: var(--spacing-lg);
    width: 100%;
    padding: var(--spacing-xl) var(--spacing-lg);
  }
  
  .navbar ul li {
    width: 100%;
    text-align: center;
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.3s ease;
  }
  
  .navbar.active ul li {
    opacity: 1;
    transform: translateY(0);
  }
  
  .navbar.active ul li:nth-child(1) { transition-delay: 0.1s; }
  .navbar.active ul li:nth-child(2) { transition-delay: 0.15s; }
  .navbar.active ul li:nth-child(3) { transition-delay: 0.2s; }
  .navbar.active ul li:nth-child(4) { transition-delay: 0.25s; }
  
  .navbar a {
    display: block;
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: var(--font-size-lg);
    color: #ffffff;
    transition: all 0.3s ease;
  }
  
  .navbar a:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: scale(1.05);
  }
}

/* ========================================
   BUTTONS
   ======================================== */
.btn {
  background-color: var(--color-bg-light);
  color: var(--color-primary);
  border: 2px solid transparent;
  padding: var(--spacing-sm) var(--spacing-xl);
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: var(--font-size-base);
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition: all var(--transition-base);
}

.btn::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: var(--color-primary-dark);
  transform: translate(-50%, -50%);
  transition: width var(--transition-base), height var(--transition-base);
  z-index: 0;
}

.btn:hover::before {
  width: 300px;
  height: 300px;
}

.btn:hover {
  color: var(--color-text-primary);
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

.btn span {
  position: relative;
  z-index: 1;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-accent) 0%, var(--color-accent-hover) 100%);
  color: var(--color-text-primary);
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--color-text-primary);
  color: var(--color-text-primary);
}

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

/* ========================================
   ABOUT SECTION
   ======================================== */
.About-section {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
  padding: var(--spacing-3xl) var(--spacing-xl);
  position: relative;
  overflow: hidden;
}

.About-section::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
  border-radius: 50%;
  animation: float 6s ease-in-out infinite;
}

@keyframes float {
  0%, 100% {
    transform: translateY(0) rotate(0deg);
  }
  50% {
    transform: translateY(-30px) rotate(180deg);
  }
}

.about-me {
  color: var(--color-text-primary);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--spacing-2xl);
  max-width: var(--container-max-width);
  margin: 0 auto;
  animation: fadeInUp 0.8s ease-out;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.about-text {
  flex: 1;
  max-width: 600px;
}

.about-text h1 {
  font-size: var(--font-size-4xl);
  margin-bottom: var(--spacing-lg);
  font-weight: 700;
  line-height: 1.2;
  color: #ffffff;
}

.about-text p {
  font-size: var(--font-size-lg);
  line-height: 1.8;
  margin-bottom: var(--spacing-xl);
  color: #ffffff;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
}

/* My Journey Button Styling */
.about-text .btn {
  background: linear-gradient(135deg, #4a90e2 0%, #357abd 100%);
  color: white;
  padding: 10px 20px;
  border-radius: 25px;
  display: inline-block;
  font-weight: 600;
  transition: all 0.3s ease;
  box-shadow: 0 4px 12px rgba(74, 144, 226, 0.3);
}

.about-text .btn:hover {
  background: linear-gradient(135deg, #357abd 0%, #4a90e2 100%);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(74, 144, 226, 0.4);
}

.about-image {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  box-shadow: var(--shadow-xl);
  transition: transform var(--transition-base);
  animation: pulse 3s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% {
    box-shadow: 0 0 0 0 rgba(255, 255, 255, 0.4);
  }
  50% {
    box-shadow: 0 0 0 20px rgba(255, 255, 255, 0);
  }
}

.about-image:hover {
  transform: scale(1.1) rotate(5deg);
}

/* ========================================
   PROJECTS SECTION
   ======================================== */
.projects-section {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
  padding: var(--spacing-3xl) var(--spacing-xl);
  color: var(--color-text-primary);
}

.projects-section h2 {
  font-size: var(--font-size-3xl);
  margin-bottom: var(--spacing-2xl);
  text-align: center;
  font-weight: 700;
  animation: fadeIn 0.8s ease-out;
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

.scrolling-wrapper {
  display: flex;
  overflow-x: auto;
  gap: var(--spacing-xl);
  padding: var(--spacing-lg) var(--spacing-sm) var(--spacing-xl);
  scroll-behavior: smooth;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  max-width: var(--container-max-width);
  margin: 0 auto;
}

.scrolling-wrapper::-webkit-scrollbar {
  height: 10px;
}

.scrolling-wrapper::-webkit-scrollbar-track {
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-full);
}

.scrolling-wrapper::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.3);
  border-radius: var(--radius-full);
  transition: background var(--transition-base);
}

.scrolling-wrapper::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.5);
}

.project-card {
  flex: 0 0 300px;
  min-width: 300px;
  padding: var(--spacing-xl);
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, var(--color-bg-card) 0%, #132a4a 100%);
  color: var(--color-text-primary);
  text-decoration: none;
  transition: all var(--transition-base);
  border: 1px solid rgba(255, 255, 255, 0.1);
  scroll-snap-align: start;
  position: relative;
  overflow: hidden;
  animation: slideIn 0.6s ease-out backwards;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateX(50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.project-card:nth-child(1) { animation-delay: 0.1s; }
.project-card:nth-child(2) { animation-delay: 0.2s; }
.project-card:nth-child(3) { animation-delay: 0.3s; }
.project-card:nth-child(4) { animation-delay: 0.4s; }
.project-card:nth-child(5) { animation-delay: 0.5s; }

.project-card::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: linear-gradient(45deg, transparent, rgba(255, 255, 255, 0.1), transparent);
  transform: rotate(45deg);
  transition: all var(--transition-slow);
}

.project-card:hover::before {
  left: 100%;
}

.project-card:hover {
  transform: translateY(-10px) scale(1.02);
  box-shadow: var(--shadow-xl);
  border-color: rgba(255, 255, 255, 0.3);
}

.card-icon {
  background: linear-gradient(135deg, #ffffff 0%, #f0f0f0 100%);
  width: 70px;
  height: 70px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  margin-bottom: var(--spacing-lg);
  transition: transform var(--transition-base);
  box-shadow: var(--shadow-md);
}

.project-card:hover .card-icon {
  transform: rotate(10deg) scale(1.1);
}

.card-icon img {
  max-width: 50px;
  max-height: 50px;
}

.project-card h3 {
  font-size: var(--font-size-xl);
  margin-bottom: var(--spacing-sm);
  font-weight: bold;
  transition: color var(--transition-base);
}

.project-card p {
  font-size: var(--font-size-base);
  color: #e0e0e0;
  line-height: 1.6;
}

/* ========================================
   FOOTER
   ======================================== */
footer {
  background: linear-gradient(135deg, var(--color-primary-dark) 0%, #000000 100%);
  color: var(--color-text-primary);
  padding: var(--spacing-2xl) var(--spacing-xl);
  text-align: center;
}

footer p {
  margin-bottom: var(--spacing-md);
  font-size: var(--font-size-base);
}

footer a {
  color: var(--color-accent);
  font-weight: 600;
  transition: color var(--transition-base);
}

footer a:hover {
  color: var(--color-accent-hover);
  text-decoration: underline;
}

/* ========================================
   UTILITY CLASSES
   ======================================== */
.container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-xl);
}

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

.fade-in {
  animation: fadeIn 0.8s ease-out;
}

.slide-up {
  animation: fadeInUp 0.8s ease-out;
}

/* ========================================
   RESPONSIVE DESIGN - MOBILE FIRST
   ======================================== */

/* Tablets (768px and up) */
@media (max-width: 768px) {
  :root {
    --font-size-4xl: 2rem;
    --font-size-3xl: 1.5rem;
    --spacing-3xl: 2rem;
  }
  
  .header-container {
    flex-wrap: wrap;
    padding: var(--spacing-md);
  }
  
  .navbar {
    width: 100%;
    margin-top: var(--spacing-md);
  }
  
  #nav-menu {
    display: none;
    transition: 0.3s;
  }
  
  #nav-menu.active {
    display: flex !important;
    flex-direction: column;
    width: 100%;
    gap: var(--spacing-sm);
  }
  
  .navbar ul {
    flex-direction: column;
    width: 100%;
    gap: var(--spacing-sm);
  }
  
  .navbar a {
    display: block;
    width: 100%;
    text-align: center;
  }
  
  .mobile-nav-toggle {
    display: block;
  }
  
  .about-me {
    flex-direction: column;
    text-align: center;
    gap: var(--spacing-xl);
  }
  
  .about-text {
    max-width: 100%;
  }
  
  .about-text p {
    font-size: var(--font-size-base);
  }
  
  .about-image {
    width: 120px;
    height: 120px;
  }
  
  .projects-section {
    padding: var(--spacing-2xl) var(--spacing-md);
  }
  
  .scrolling-wrapper {
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-xs);
  }
  
  .project-card {
    flex: 0 0 280px;
    min-width: 280px;
    padding: var(--spacing-lg);
  }
}

/* Mobile (576px and down) */
@media (max-width: 576px) {
  :root {
    --font-size-4xl: 1.75rem;
    --font-size-3xl: 1.25rem;
    --spacing-xl: 1.25rem;
  }
  
  .logo {
    width: 35px;
    height: 35px;
  }
  
  .about-text h1 {
    font-size: var(--font-size-3xl);
  }
  
  .project-card {
    flex: 0 0 260px;
    min-width: 260px;
  }
  
  .About-section, .projects-section {
    padding: var(--spacing-xl) var(--spacing-md);
  }
}

/* Large Desktops (1440px and up) */
@media (min-width: 1440px) {
  :root {
    --container-max-width: 1400px;
    --font-size-5xl: 3.5rem;
    --font-size-4xl: 2.75rem;
  }
}