:root {
  --bg-color: #0f172a;
  --card-bg: #1e293b;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --primary: #38bdf8;
  --accent: #3b82f6;
}

body.light-theme {
  --bg-color: #f8fafc;
  --card-bg: #ffffff;
  --text-main: #0f172a;
  --text-muted: #64748b;
  --primary: #0284c7;
  --accent: #2563eb;
}

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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.6;
  padding: 40px 20px;
  transition: background-color 0.3s, color 0.3s;
}

.container {
  max-width: 800px;
  margin: 0 auto;
}

.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 40px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--card-bg);
}

.header h1 {
  font-size: 2.2rem;
  color: var(--primary);
}

.tagline {
  color: var(--text-muted);
  font-size: 1.1rem;
}

.btn-theme {
  background: var(--card-bg);
  color: var(--text-main);
  border: 1px solid var(--primary);
  padding: 8px 16px;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s;
}

.btn-theme:hover {
  background: var(--primary);
  color: #fff;
}

.section {
  margin-bottom: 35px;
}

.section h2 {
  font-size: 1.5rem;
  margin-bottom: 15px;
  color: var(--primary);
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 15px;
}

.skill-card, .project-item {
  background: var(--card-bg);
  padding: 20px;
  border-radius: 10px;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.skill-card h3, .project-item h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
  color: var(--text-main);
}

.skill-card p, .project-item p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.projects-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer {
  text-align: center;
  margin-top: 50px;
  padding-top: 20px;
  color: var(--text-muted);
  font-size: 0.9rem;
}