/* ========================
   GLOBAL / VARIABLES
   ======================== */
:root {
  --primary: #000066;
  --secondary: #000000;
  --background: #ffffff;
  --accent: #ff4081;
  --step--1: 0.667rem;
  --step-0: 1rem;
  --step-1: 1.5rem;
  --step-2: 2.25rem;
  --step-3: 3.375rem;
  --step-4: 5.063rem;
}

[data-theme="dark"] {
  --primary: #00ffff;
  --secondary: #ffffff;
  --background: #000066;
  --accent: #ff4081;
}

/* ========================
   RESET & BASE
   ======================== */
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--background);
  color: var(--secondary);
  font-family: 'Inter', sans-serif;
  line-height: 1.6;
  transition: background .4s, color .4s;
}

/* Typography */
.brand {
  font-family: 'Poppins', sans-serif;
  font-size: var(--step-2);
  color: var(--primary);
  font-weight: 700;
}

/* Section titles */
.section-title {
  font-family: 'Montserrat', sans-serif;
  font-size: var(--step-2);
  color: var(--primary);
  text-align: center;
  margin-bottom: 1.5rem;
}

/* ========================
   BANNER / NAV
   ======================== */
.banner {
  position: sticky;
  top: 0;
  background: var(--background);
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  border-bottom: 2px solid var(--primary);
  z-index: 10;
}

.nav-links a {
  margin: 0 0.8rem;
  text-decoration: none;
  color: var(--secondary);
  font-weight: 500;
  transition: color .3s;
}

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

.mode-btn {
  width: 36px; height: 36px;
  border: 2px solid var(--primary);
  border-radius: 50%;
  background: var(--primary);
  cursor: pointer;
  transition: all .3s;
}
[data-theme="dark"] .mode-btn { background: var(--secondary); }

/* ========================
   HOME
   ======================== */
.section { padding: 4rem 1.5rem; }
.home { text-align: center; }

.photo-border {
  width: 160px; height: 160px;
  margin: 0 auto 1.5rem;
  border: 5px solid var(--primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  animation: spin-border 8s linear infinite;
}

.photo-inner {
  width: 145px; height: 145px; /* slightly smaller than border */
  border-radius: 50%;
  overflow: hidden;
}

.profile-pic {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 50%;
}

@keyframes spin-border {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.typing-heading {
  font-family: 'Poppins', sans-serif;
  font-size: var(--step-2);
  margin-bottom: 1rem;
}

.cursor {
  color: var(--primary);
  animation: blink 0.7s infinite;
}

@keyframes blink {
  0%, 50%, 100% { opacity: 1; }
  25%, 75% { opacity: 0; }
}

.about-text {
  max-width: 600px;
  margin: 0 auto;
  font-size: var(--step-0);
}

/* ========================
   CV TIMELINE
   ======================== */
.timeline {
  position: relative;
  max-width: 700px;
  margin: 0 auto;
  padding-left: 2rem;
  border-left: 3px solid var(--primary);
}
.timeline-item { margin-bottom: 1.5rem; }
.timeline-date { font-weight: 700; color: var(--primary); }
.timeline-content h3 { font-family: 'Montserrat'; color: var(--secondary); }
.timeline-content p { margin-top: 0.25rem; }

/* ========================
   SKILLS
   ======================== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  max-width: 800px;
  margin: 0 auto;
}
.skill-category h3 { color: var(--primary); margin-bottom: 0.5rem; }

/* ========================
   PROJECTS
   ======================== */
.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
  max-width: 900px;
  margin: 0 auto;
  text-align: center;
}
.project-card {
  background: var(--background);
  border: 2px solid var(--primary);
  border-radius: 1rem;
  overflow: hidden;
  text-decoration: none;
  color: var(--secondary);
  transition: transform .3s, box-shadow .3s;
}
.project-card:hover {
  transform: scale(1.05);
  box-shadow: 0 0 15px var(--accent);
}
.project-card img { width: 100%; height: 150px; object-fit: cover; }
.project-card p { padding: 0.5rem; }

/* ========================
   ACHIEVEMENTS
   ======================== */
.achievements-list {
  max-width: 600px;
  margin: 0 auto;
  list-style: square;
  padding-left: 1.5rem;
  font-size: var(--step-0);
}

/* ========================
   CONTACT
   ======================== */
.contact-buttons {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
}
.btn {
  text-decoration: none;
  background: var(--primary);
  color: var(--background);
  padding: 0.75rem 1.5rem;
  border-radius: 2rem;
  transition: all .3s;
}
.btn:hover {
  background: var(--accent);
  transform: scale(1.07);
  box-shadow: 0 0 10px var(--accent);
}

/* ========================
   FOOTER
   ======================== */
.footer {
  text-align: center;
  padding: 1rem;
  font-size: var(--step--1);
  color: var(--secondary);
}

/* ========================
   RESPONSIVE TYPE SCALE
   ======================== */
@media (max-width: 767px) {
  :root {
    --step--1: 0.667rem;
    --step-0: 1rem;
    --step-1: 1.5rem;
    --step-2: 2.25rem;
    --step-3: 3.375rem;
    --step-4: 5.063rem; /* Perfect Fifth */
  }
}

@media (min-width: 768px) {
  :root {
    --step--1: 0.875rem;
    --step-0: 1rem;
    --step-1: 1.125rem;
    --step-2: 1.26rem;
    --step-3: 1.42rem;
    --step-4: 1.6rem; /* Major Second */
  }
}