* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
:root {
    --bg-color: #0a0a0a;
    --text-color: #e0e0e0;
    --accent-color: #00ffcc;
    --highlight-color: #ff00cc;
    --card-bg: rgba(15, 15, 15, 0.85);
}

body.light-mode{
    --bg-color: #ffffff;
    --text-color: #1a1a1a;
    --accent-color: #007acc;
    --highlight-color: #cc007a;
    --card-bg: #f5f5f5;
}

body {
    font-family: 'Arial', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    background-image: url('images/tech-background.jpg');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    line-height: 1.6;
    padding: 20px;
    transition: background-color 0.3s ease, color 0.3s ease;
}
header {
    background-color: rgba(0, 0, 0, 0.7);
    padding: 20px;
    text-align: center;
    border-bottom: 2px solid var(--accent-color);
    box-shadow: 0 0 8px var(--accent-color);
}

nav {
    margin-top: 10px;
}

nav a {
    color: var(--accent-color);
    text-decoration: none;
    margin: 0 15px;
    font-size: 18px;
    transition: color 0.3s ease;
}

nav a:hover {
    color: var(--highlight-color);
    text-decoration: underline;
}

.toggle-btn {
    background: none;
    border: 2px solid var(--accent-color);
    color: var(--accent-color);
    padding: 6px 12px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 14px;
    margin-top: 15px;
    transition: all 0.3s ease;
}

.toggle-btn:hover {
    background-color: var(--accent-color);
    color: #000;
}

section {
    max-width: 900px;
    margin: 0 auto;
    background-color: var(--card-bg);
    padding: 30px;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 0 10px var(--accent-color);
    transition: background-color 0.3s ease;
}
section {
  display: none;
}

section.active {
  display: block;
}


section h2 {
    margin-bottom: 15px;
}

section p {
    font-size: 18px;
    margin-bottom: 20px;
}

#typewriter-heading::after {
    content: '|';
    color: var(--accent-color);
    animation: blink 0.7s infinite;
}

@keyframes blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0; }
}

.skills-list {
    max-width: 700px;
    margin: 0 auto 20px auto;
    text-align: left;
}

.skills-list li {
    font-size: 17px;
    margin-bottom: 10px;
}

img.responsive {
    max-width: 100%;
    height: auto;
    margin-top: 20px;
    border: 2px solid var(--accent-color);
    border-radius: 10px;
    box-shadow: 0 0 15px var(--accent-color);
}

footer {
    text-align: center;
    padding: 20px;
    font-size: 14px;
    color: #888;
    margin-top: 40px;
}

@media (max-width: 600px) {
    nav a {
        display: block;
        margin: 10px 0;
    }

    header h1 {
        font-size: 28px;
    }

    section h2 {
        font-size: 24px;
    }

        section p, .skills-list li {
            font-size: 16px;
        }
    }  

#activities {
  padding: 40px 15px;
  background: linear-gradient(135deg, #0a0a0a, #1a1a1a);
  color: #e0e0e0;
  text-align: center;
  border-radius: 10px;
  max-width: 800px;
  margin: 40px auto;
}

#activities h2 {
  font-size: 2rem; 
  margin-bottom: 8px;
  color: var(--accent-color);
  text-transform: uppercase;
  letter-spacing: 1.5px;
}

#activities p {
  font-size: 1rem;
  margin-bottom: 30px;
  color: #cccccc;
}

.activities-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
  max-width: 900px;
  margin: 0 auto;
}
.activity-card {
  position: relative;
  border-radius: 12px;
  overflow: hidden;
  cursor: pointer;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.activity-card img {
  width: 100%;
  height: 180px;
  object-fit: cover;
  display: block;
  filter: brightness(85%);
  border-radius: 12px;
}
.activity-card p {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  padding: 12px;
  font-size: 0.9rem;
  color: #fff;
  background: linear-gradient(transparent, rgba(0, 0, 0, 0.7));
  text-align: left;
}
.activity-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 6px 15px rgba(0, 255, 204, 0.25);
}
.lightbox {
  display: none;
  position: fixed;
  z-index: 1000;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: rgba(0,0,0,0.9);
  justify-content: center;
  align-items: center;
}
.lightbox img {
  max-width: 90%;
  max-height: 90%;
  border-radius: 10px;
  box-shadow: 0 0 20px rgba(0,255,204,0.6);
}
.lightbox .close {
  position: absolute;
  top: 20px;
  right: 30px;
  font-size: 2rem;
  color: #fff;
  cursor: pointer;
  font-weight: bold;
}