:root {
  --orange: #ff8c42;
  --orange-dark: #e67e22;
  --gray-light: #f5f5f5;
  --text-dark: #2c3e50;
  --text-light: #7f8c8d;
  --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  --shadow-hover: 0 6px 12px rgba(0, 0, 0, 0.15);
  --transition: all 0.3s ease;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: system-ui, sans-serif;
  color: var(--text-dark);
  background: #fff;
  line-height: 1.6;
  font-size: 16px;
}

/* HEADER */
.header {
  background: linear-gradient(135deg, var(--orange), var(--orange-dark));
  color: #fff;
  text-align: center;
  padding: 3rem 1.5rem;
  box-shadow: var(--shadow);
}

.header h1 {
  font-size: 2.2rem;
  margin-bottom: 0.5rem;
}

.subtitle {
  font-size: 1rem;
  opacity: 0.9;
}

.greeting {
  font-size: 1.2rem;
  font-weight: 600;
  margin-top: 1rem;
  animation: fadeIn 0.8s ease-out;
}

/* NAVBAR */
.navbar {
  background: #fff;
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0.5rem 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 0.5rem;
}

.nav-link {
  text-decoration: none;
  color: var(--text-dark);
  padding: 0.6rem 1rem;
  transition: var(--transition);
  border-bottom: 2px solid transparent;
}

.nav-link:hover,
.nav-link.active {
  color: var(--orange);
  border-bottom-color: var(--orange);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  border: none;
  background: none;
  cursor: pointer;
}

.nav-toggle span {
  width: 25px;
  height: 3px;
  background: var(--text-dark);
}

/* MAIN CONTENT */
.main-content {
  max-width: 1100px;
  margin: 2rem auto;
  padding: 0 1.5rem;
}

section {
  margin-bottom: 4rem;
  text-align: center;
}

h2 {
  font-size: 1.8rem;
  color: var(--text-dark);
  margin-bottom: 1.5rem;
  position: relative;
}

h2::after {
  content: "";
  display: block;
  width: 60px;
  height: 3px;
  background: var(--orange);
  margin: 0.5rem auto;
  border-radius: 2px;
}

/* QUICK ACCESS BOXES */
.link-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
}

.link-box {
  background: var(--gray-light);
  padding: 2rem 1rem;
  border-radius: 12px;
  text-decoration: none;
  color: var(--text-dark);
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.link-box:hover {
  background: #fff;
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border: 1px solid var(--orange);
}

.link-icon {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
}

/* DEMO SECTION */
.interactive-demos {
  background: var(--gray-light);
  padding: 2rem;
  border-radius: 12px;
}

.demo-placeholder {
  background: #fff;
  border: 2px dashed var(--orange);
  padding: 2rem;
  border-radius: 12px;
  animation: fadeIn 0.6s ease-out;
}

.demo-icon {
  font-size: 3rem;
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

/* CATEGORY CARDS */
.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
}

.category-card {
  background: #fff;
  border: 1px solid var(--gray-light);
  border-radius: 10px;
  box-shadow: var(--shadow);
  padding: 1.5rem;
  transition: var(--transition);
}

.category-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: var(--orange);
}

.category-card h3 {
  margin-bottom: 0.5rem;
  color: var(--orange-dark);
}

.category-link {
  display: inline-block;
  color: var(--orange);
  text-decoration: none;
  font-weight: 600;
  margin-top: 1rem;
}

.category-link:hover {
  text-decoration: underline;
}

/* FOOTER */
.footer {
  background: var(--orange);
  color: #fff;
  text-align: center;
  padding: 1.5rem;
  margin-top: 4rem;
}

/* MOBILE */
@media (max-width: 768px) {
  .nav-toggle { display: flex; }
  .nav-menu {
    position: absolute;
    top: 60px;
    left: 0;
    background: #fff;
    width: 100%;
    flex-direction: column;
    overflow: hidden;
    max-height: 0;
    transition: var(--transition);
  }
  .nav-menu.active { max-height: 300px; }
  .nav-link {
    border-bottom: 1px solid var(--gray-light);
    padding: 1rem;
  }
}

/* SIMPLE ANIMATIONS */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}
/* Extra styling for essays page */
.essays-section {
  max-width: 800px;
  margin: 2rem auto;
  padding: 1rem 2rem;
  background-color: #fffaf5;
  border-radius: 10px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.essays-section h2 {
  color: #d35400;
  text-align: center;
  margin-bottom: 1.5rem;
}

.essay-item {
  margin-bottom: 1.5rem;
  padding: 1rem;
  background-color: #fff5ee;
  border-left: 5px solid #f39c12;
  border-radius: 5px;
}

.essay-item h3 {
  margin-bottom: 0.5rem;
}

.essay-item a {
  color: #e67e22;
  font-weight: bold;
  text-decoration: none;
}

.essay-item a:hover {
  text-decoration: underline;
}
/* Code project styles */
.project {
  background: #fff0f5;
  padding: 20px;
  margin: 20px;
  border-radius: 15px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}

.project h2 {
  color: #d63384;
}

pre {
  background: #f8f9fa;
  border-radius: 10px;
  padding: 15px;
  overflow-x: auto;
}

code {
  font-family: "Fira Code", monospace;
  color: #333;
  font-size: 0.95em;
}

.file-list {
    list-style: none;
    padding-left: 0;
}

.file-list li {
    margin: 10px 0;
}

.file-list a {
    display: inline-block;
    padding: 10px 15px;
    background: #fff0f5;
    border-radius: 8px;
    text-decoration: none;
    color: #333;
    border: 1px solid #e2c4d4;
    transition: 0.3s ease;
}

.file-list a:hover {
    background: #ffe6f0;
    border-color: #d39ab8;
}

.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.video-box {
    background: #f5f5f5;
    padding: 1rem;
    border-radius: 10px;
    box-shadow: var(--shadow);
}

.video-box h3 {
    margin-bottom: 1rem;
    font-size: 1.2rem;
}