/* =========== CUSTOM PROPERTIES =========== */
:root {
  /* Colors */
  --portfolio-primary: #3b82f6;
  --portfolio-accent: #2563eb;
  --portfolio-light: #f0f9ff;
  --color-white: #ffffff;
  --color-black: #000000;
  --color-gray-100: #f8f9fa;
  --color-gray-200: #e9ecef;
  --color-gray-300: #dee2e6;
  --color-gray-400: #ced4da;
  --color-gray-500: #adb5bd;
  --color-gray-600: #6c757d;
  --color-gray-700: #495057;
  --color-gray-800: #343a40;
  --color-gray-900: #212529;
  
  /* Font Family */
  --font-sans: 'Inter', sans-serif;
  --font-heading: 'Poppins', sans-serif;
  
  /* Font Sizes */
  --fs-sm: 0.875rem;
  --fs-base: 1rem;
  --fs-md: 1.125rem;
  --fs-lg: 1.25rem;
  --fs-xl: 1.5rem;
  --fs-2xl: 1.875rem;
  --fs-3xl: 2.25rem;
  --fs-4xl: 3rem;
  --fs-5xl: 3.75rem;
  
  /* Spacing */
  --spacing-1: 0.25rem;
  --spacing-2: 0.5rem;
  --spacing-3: 0.75rem;
  --spacing-4: 1rem;
  --spacing-6: 1.5rem;
  --spacing-8: 2rem;
  --spacing-12: 3rem;
  --spacing-16: 4rem;
  
  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.375rem;
  --radius-lg: 0.5rem;
  --radius-xl: 0.75rem;
  --radius-full: 9999px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  
  /* Transitions */
  --transition-base: all 0.3s ease;
  --transition-fast: all 0.15s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  color: var(--color-gray-800);
  background-color: var(--color-white);
  line-height: 1.6;
}

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

ul {
  list-style: none;
}

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

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

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: 4rem 0;
}

.section-title {
  font-family: var(--font-heading);
  font-size: var(--fs-3xl);
  font-weight: 700;
  color: var(--portfolio-accent);
  text-align: center;
  margin-bottom: 2.5rem;
  position: relative;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -0.75rem;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 4px;
  background-color: var(--portfolio-primary);
  border-radius: var(--radius-full);
}

.bg-light {
  background-color: var(--portfolio-light);
}

/* =========== HEADER STYLES =========== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background-color: var(--color-white);
  box-shadow: var(--shadow-sm);
  padding: 1.25rem 0;
  z-index: 100;
  transition: var(--transition-base);
}

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

.header.sticky {
  padding: 0.75rem 0;
  box-shadow: var(--shadow-md);
}

.logo {
  font-family: var(--font-heading);
  font-size: var(--fs-xl);
  font-weight: 700;
  color: var(--portfolio-primary);
}

.logo span {
  color: var(--portfolio-accent);
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-link {
  font-weight: 500;
  position: relative;
  padding: 0.5rem 0;
}

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

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

.nav-link.active {
  color: var(--portfolio-primary);
}

.nav-toggle,
.nav-close {
  display: none;
  font-size: var(--fs-xl);
  cursor: pointer;
  color: var(--color-gray-800);
}

/* =========== HERO SECTION =========== */
.hero-section {
  padding-top: 7rem;
  padding-bottom: 4rem;
  background: linear-gradient(to bottom right, var(--color-white), var(--portfolio-light));
}

.hero-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.profile-image {
  width: 8rem;
  height: 8rem;
  border-radius: 50%;
  border: 4px solid var(--portfolio-primary);
  overflow: hidden;
  position: relative;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow-lg);
}

.profile-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.profile-fallback {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--color-gray-300);
  color: var(--color-gray-800);
  font-weight: 700;
  font-size: var(--fs-xl);
}

.hero-name {
  font-family: var(--font-heading);
  font-size: var(--fs-4xl);
  font-weight: 700;
  color: var(--portfolio-accent);
  margin-bottom: 1rem;
}

.hero-title {
  font-size: var(--fs-lg);
  font-weight: 500;
  color: var(--color-gray-700);
  margin-bottom: 1.5rem;
}

.contact-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 2rem;
}

.contact-link {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  background-color: var(--color-white);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-sm);
  color: var(--color-gray-700);
  font-size: var(--fs-sm);
}

.contact-link:hover {
  box-shadow: var(--shadow-md);
  color: var(--portfolio-primary);
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  margin-top: 1rem;
}

.primary-btn {
  display: inline-block;
  padding: 0.75rem 2rem;
  background-color: var(--portfolio-primary);
  color: var(--color-white);
  border-radius: var(--radius-md);
  font-weight: 500;
  transition: var(--transition-base);
}

.primary-btn:hover {
  background-color: var(--portfolio-accent);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.secondary-btn {
  display: inline-block;
  padding: 0.75rem 2rem;
  background-color: transparent;
  color: var(--portfolio-primary);
  border: 2px solid var(--portfolio-primary);
  border-radius: var(--radius-md);
  font-weight: 500;
  transition: var(--transition-base);
}

.secondary-btn:hover {
  background-color: var(--portfolio-light);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

/* =========== ABOUT SECTION =========== */
.about-content {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

.about-text p {
  margin-bottom: 1rem;
  line-height: 1.7;
}

.about-info {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

.info-item {
  display: flex;
  flex-direction: column;
  padding: 1rem;
  background-color: var(--color-white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}

.info-item h4 {
  font-weight: 600;
  color: var(--portfolio-primary);
  margin-bottom: 0.5rem;
}

/* =========== EDUCATION SECTION =========== */
.timeline-container {
  position: relative;
}

.timeline-container::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0.75rem;
  width: 3px;
  background-color: var(--portfolio-primary);
}

.timeline-item {
  position: relative;
  padding-left: 3rem;
  margin-bottom: 2rem;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-icon {
  position: absolute;
  left: 0;
  top: 0;
  width: 2.5rem;
  height: 2.5rem;
  background-color: var(--portfolio-primary);
  color: var(--color-white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--fs-md);
}

.timeline-content {
  background-color: var(--color-white);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
}

.timeline-content h3 {
  font-weight: 600;
  color: var(--portfolio-accent);
  margin-bottom: 0.5rem;
}

.timeline-content h4 {
  font-weight: 500;
  color: var(--color-gray-700);
  margin-bottom: 0.5rem;
  font-size: var(--fs-sm);
}

.timeline-content p {
  color: var(--color-gray-600);
  margin-bottom: 0.5rem;
  font-size: var(--fs-sm);
}

.timeline-grade {
  font-weight: 600;
  color: var(--portfolio-primary) !important;
}

/* =========== SKILLS SECTION =========== */
.skills-container {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

.skills-category h3 {
  font-size: var(--fs-lg);
  font-weight: 600;
  color: var(--portfolio-primary);
  margin-bottom: 1.25rem;
}

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

.skill-item {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.skill-item span {
  font-weight: 500;
}

.skill-bar {
  height: 0.5rem;
  background-color: var(--color-gray-200);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.skill-progress {
  height: 100%;
  background-color: var(--portfolio-primary);
  border-radius: var(--radius-full);
  transition: width 1s ease-out;
}

/* =========== EXPERIENCE SECTION =========== */
.experience-container {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.experience-item {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  background-color: var(--color-white);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
}

.experience-timeline {
  font-size: var(--fs-sm);
  color: var(--color-gray-600);
}

.experience-title {
  font-size: var(--fs-lg);
  font-weight: 600;
  color: var(--portfolio-accent);
  margin-bottom: 0.25rem;
}

.experience-company {
  font-size: var(--fs-md);
  font-weight: 500;
  color: var(--color-gray-700);
  margin-bottom: 0.75rem;
}

.experience-description {
  font-size: var(--fs-base);
  color: var(--color-gray-600);
}

/* =========== PROJECTS SECTION =========== */
.projects-container {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

.project-card {
  background-color: var(--color-white);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: var(--transition-base);
}

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

.project-header {
  background-color: var(--portfolio-primary);
  color: var(--color-white);
  padding: 1.5rem;
}

.project-header h3 {
  font-size: var(--fs-lg);
  font-weight: 600;
}

.project-body {
  padding: 1.5rem;
}

.project-body p {
  margin-bottom: 1.25rem;
  line-height: 1.7;
}

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

.tag {
  font-size: var(--fs-sm);
  background-color: var(--portfolio-light);
  color: var(--portfolio-primary);
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
  font-weight: 500;
}

/* =========== ACHIEVEMENTS SECTION =========== */
.achievements-container {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

.achievement-item {
  display: flex;
  align-items: flex-start;
  gap: 1.5rem;
  background-color: var(--color-white);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
}

.achievement-icon {
  font-size: var(--fs-2xl);
  color: var(--portfolio-primary);
}

.achievement-content p {
  line-height: 1.7;
}

/* =========== CONTACT SECTION =========== */
.contact-container {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

.contact-info {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem;
  background-color: var(--color-white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: var(--transition-base);
}

.contact-item:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.contact-icon {
  font-size: var(--fs-xl);
  color: var(--portfolio-primary);
  width: 3rem;
  height: 3rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--portfolio-light);
  border-radius: 50%;
}

.contact-text h3 {
  font-size: var(--fs-md);
  font-weight: 600;
  color: var(--portfolio-accent);
  margin-bottom: 0.25rem;
}

.contact-text a:hover {
  color: var(--portfolio-primary);
}

.contact-form {
  background-color: var(--color-white);
  padding: 2rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  font-weight: 500;
  margin-bottom: 0.5rem;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  font-size: var(--fs-base);
  transition: var(--transition-base);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--portfolio-primary);
  box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.25);
}

.submit-btn {
  display: inline-block;
  padding: 0.75rem 2rem;
  background-color: var(--portfolio-primary);
  color: var(--color-white);
  border: none;
  border-radius: var(--radius-md);
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition-base);
}

.submit-btn:hover {
  background-color: var(--portfolio-accent);
}

/* =========== FOOTER STYLES =========== */
.footer {
  background-color: var(--color-gray-900);
  color: var(--color-white);
  padding: 4rem 0 1rem;
}

.footer-content {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  margin-bottom: 3rem;
}

.footer-logo h2 {
  font-family: var(--font-heading);
  font-size: var(--fs-2xl);
  font-weight: 700;
  color: var(--portfolio-primary);
  margin-bottom: 0.5rem;
}

.footer-logo p {
  color: var(--color-gray-400);
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.footer-links a {
  color: var(--color-gray-300);
}

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

.footer-social {
  display: flex;
  gap: 1rem;
}

.footer-social a {
  width: 2.5rem;
  height: 2.5rem;
  background-color: var(--color-gray-800);
  color: var(--color-white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--fs-lg);
  transition: var(--transition-base);
}

.footer-social a:hover {
  background-color: var(--portfolio-primary);
  transform: translateY(-3px);
}

.footer-bottom {
  border-top: 1px solid var(--color-gray-800);
  padding-top: 1.5rem;
  text-align: center;
  color: var(--color-gray-500);
  font-size: var(--fs-sm);
}

/* =========== ANIMATION STYLES =========== */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.animate-active {
  opacity: 1;
  transform: translateY(0);
}

/* =========== RESPONSIVE STYLES =========== */
@media screen and (max-width: 768px) {
  .nav-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 70%;
    height: 100vh;
    background-color: var(--color-white);
    box-shadow: var(--shadow-lg);
    padding: 4rem 2rem;
    transition: 0.4s;
    z-index: 100;
  }
  
  .nav-menu.active {
    right: 0;
  }
  
  .nav-list {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .nav-toggle,
  .nav-close {
    display: inline-flex;
  }
  
  .nav-close {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
  }
  
  .hero-name {
    font-size: var(--fs-3xl);
  }
  
  .hero-title {
    font-size: var(--fs-md);
  }
  
  .contact-links {
    flex-direction: column;
    align-items: center;
  }
}

@media screen and (min-width: 768px) {
  .section-title {
    font-size: var(--fs-4xl);
  }
  
  .about-content,
  .skills-container {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .about-info {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .timeline-container::before {
    left: 50%;
    transform: translateX(-50%);
  }
  
  .timeline-item {
    padding-left: 0;
    padding-right: 0;
  }
  
  .timeline-item:nth-child(odd) {
    padding-right: 50%;
    padding-left: 2rem;
    text-align: right;
  }
  
  .timeline-item:nth-child(even) {
    padding-left: 50%;
    padding-right: 2rem;
  }
  
  .timeline-icon {
    left: 50%;
    transform: translateX(-50%);
  }
  
  .projects-container {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .experience-item,
  .contact-container {
    grid-template-columns: 1fr 2fr;
  }
  
  .footer-content {
    grid-template-columns: repeat(3, 1fr);
  }
  
  .contact-info {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media screen and (min-width: 992px) {
  .projects-container {
    grid-template-columns: repeat(3, 1fr);
  }
  
  .skills-container {
    grid-template-columns: repeat(4, 1fr);
  }
}