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

:root {
  --bg-color: #f9fafb;
  --text-color: #1f2933;
  --card-bg: #ffffff;
  --primary: #2563eb;
  --secondary: #64748b;
  --border: #e5e7eb;
}

body.dark {
  --bg-color: #0f172a;
  --text-color: #e5e7eb;
  --card-bg: #1e293b;
  --primary: #60a5fa;
  --secondary: #94a3b8;
  --border: #334155;
}

body {
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.7;
  transition: background 0.3s, color 0.3s;
}

/* ==============================
   NAVBAR
============================== */
nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 18px 60px;
  border-bottom: 1px solid var(--border);
  background-color: var(--bg-color);
  position: sticky;
  top: 0;
  z-index: 100;
}

nav .logo {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--primary);
}

nav ul {
  list-style: none;
  display: flex;
  gap: 28px;
}

nav ul li a {
  text-decoration: none;
  color: var(--secondary);
  font-weight: 500;
  transition: color 0.2s;
}

nav ul li a:hover {
  color: var(--primary);
}

.toggle-theme {
  cursor: pointer;
  font-size: 1.2rem;
}

/* ==============================
   LAYOUT
============================== */
.container {
  max-width: 1100px;
  margin: 80px auto;
  padding: 0 20px;
}

h1, h2, h3 {
  font-weight: 700;
}

h2 {
  margin-bottom: 24px;
  font-size: 2rem;
}

/* ==============================
   HERO
============================== */
.hero {
  min-height: 80vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 0 20px;
}

.hero h1 {
  font-size: 3rem;
  margin-bottom: 16px;
}

.hero span {
  color: var(--primary);
}

.hero p {
  color: var(--secondary);
  margin-bottom: 32px;
  font-size: 1.1rem;
}

/* ==============================
   BUTTON
============================== */
.btn {
  display: inline-block;
  padding: 12px 28px;
  background-color: var(--primary);
  color: #ffffff;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  transition: transform 0.2s, opacity 0.2s;
}

.btn:hover {
  transform: translateY(-2px);
  opacity: 0.9;
}

/* ==============================
   GRID & CARD
============================== */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.card {
  background-color: var(--card-bg);
  padding: 24px;
  border-radius: 12px;
  border: 1px solid var(--border);
  transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
}

.card h3 {
  margin-bottom: 12px;
  font-size: 1.2rem;
}

.card p {
  color: var(--secondary);
  font-size: 0.95rem;
}

/* ==============================
   PROJECT LINKS
============================== */
.project-links {
  margin-top: 16px;
  display: flex;
  gap: 16px;
}

.project-links a {
  text-decoration: none;
  font-weight: 600;
  color: var(--primary);
}

/* ==============================
   CONTACT
============================== */
.contact-list {
  margin-top: 32px;
  display: grid;
  gap: 20px;
}

.contact-item strong {
  display: block;
  margin-bottom: 6px;
}

.contact-item a {
  color: var(--primary);
  text-decoration: none;
}

.contact-item a:hover {
  text-decoration: underline;
}

/* ==============================
   ANIMATION
============================== */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.6s ease;
}

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

/* ==============================
   RESPONSIVE
============================== */
@media (max-width: 768px) {
  nav {
    padding: 16px 24px;
  }

  nav ul {
    gap: 16px;
  }

  .hero h1 {
    font-size: 2.2rem;
  }

  h2 {
    font-size: 1.6rem;
  }
}