@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;500;600;700;800&family=Inter:wght@300;400;500&display=swap');

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

:root {
  --bg-primary: #0d0a1a;
  --bg-secondary: #1a1035;
  --bg-card: #221445;
  --accent: #a855f7;
  --accent-light: #d8b4fe;
  --accent-gradient: linear-gradient(135deg, #a855f7, #7c3aed);
  --text-primary: #e6edf3;
  --text-secondary: #8b949e;
  --border: #3b1f5e;
  --nav-height: 68px;
  --glow-sm: 0 0 12px rgba(168, 85, 247, 0.5);
  --glow-md: 0 0 24px rgba(168, 85, 247, 0.55), 0 0 48px rgba(168, 85, 247, 0.25);
  --glow-lg: 0 0 40px rgba(168, 85, 247, 0.6), 0 0 80px rgba(168, 85, 247, 0.3);
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
}

/* ── Navigation ── */
nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-height);
  background: rgba(13, 10, 26, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 20px rgba(168, 85, 247, 0.2);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  z-index: 1000;
}

.nav-logo {
  font-family: 'Poppins', sans-serif;
  font-size: 1.4rem;
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-decoration: none;
  letter-spacing: -0.5px;
  filter: drop-shadow(0 0 8px rgba(168, 85, 247, 0.7));
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.88rem;
  font-weight: 500;
  transition: color 0.25s;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px; left: 0;
  width: 0; height: 2px;
  background: var(--accent-gradient);
  border-radius: 2px;
  transition: width 0.25s;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--accent-light);
}

.nav-links a.active::after,
.nav-links a:hover::after {
  width: 100%;
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 5px;
  background: none;
  border: none;
}

.hamburger span {
  width: 25px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all 0.3s;
  display: block;
}

.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.mobile-nav {
  display: none;
  position: fixed;
  top: var(--nav-height);
  left: 0; right: 0;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  padding: 0.75rem 1rem;
  z-index: 999;
}

.mobile-nav.open { display: block; }

.mobile-nav ul { list-style: none; }

.mobile-nav a {
  display: block;
  padding: 0.7rem 1rem;
  color: var(--text-secondary);
  text-decoration: none;
  border-radius: 10px;
  transition: all 0.2s;
  font-size: 0.95rem;
}

.mobile-nav a:hover,
.mobile-nav a.active {
  background: var(--bg-card);
  color: var(--accent-light);
}

.page-content { padding-top: var(--nav-height); }

/* ── Hero ── */
.hero {
  padding: 5rem 2rem 4rem;
  text-align: center;
  background: radial-gradient(ellipse at 50% 0%, rgba(168, 85, 247, 0.35) 0%, rgba(124, 58, 237, 0.1) 40%, transparent 70%);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 4px 60px rgba(168, 85, 247, 0.12);
}

.hero-tag {
  display: inline-block;
  padding: 0.3rem 1rem;
  background: rgba(168, 85, 247, 0.12);
  border: 1px solid rgba(168, 85, 247, 0.35);
  border-radius: 50px;
  font-size: 0.82rem;
  color: var(--accent-light);
  margin-bottom: 1.25rem;
  font-weight: 500;
  letter-spacing: 0.5px;
  box-shadow: var(--glow-sm);
}

.hero h1 {
  font-family: 'Poppins', sans-serif;
  font-size: clamp(2.2rem, 5vw, 3.8rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 1rem;
}

.gradient-text {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 580px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ── Sections ── */
.section {
  padding: 3.5rem 2rem;
  max-width: 1080px;
  margin: 0 auto;
}

.section-header { margin-bottom: 1.75rem; }

.section-title {
  font-family: 'Poppins', sans-serif;
  font-size: 1.6rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 0.6rem;
}

.section-divider {
  width: 48px;
  height: 3px;
  background: var(--accent-gradient);
  border-radius: 3px;
  box-shadow: var(--glow-sm);
}

/* ── Story Card ── */
.story-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 2rem;
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.85;
}

.story-card p + p { margin-top: 1rem; }

/* ── Profile Section ── */
.profile-section {
  display: flex;
  align-items: flex-start;
  gap: 2rem;
  flex-wrap: wrap;
}

.profile-photo {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  border: 3px solid var(--accent);
  flex-shrink: 0;
  overflow: hidden;
  object-fit: cover;
  display: block;
  box-shadow: var(--glow-md);
}

.profile-photo-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-secondary);
  font-size: 3rem;
  opacity: 0.5;
}

/* ── Hobbies Grid ── */
.hobbies-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
}

.hobby-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.5rem 1rem;
  text-align: center;
  transition: all 0.3s;
  text-decoration: none;
  color: inherit;
  display: block;
}

.hobby-card:hover {
  border-color: var(--accent);
  transform: translateY(-5px);
  box-shadow: 0 12px 35px rgba(168, 85, 247, 0.3), var(--glow-sm);
  background: var(--bg-card);
}

.hobby-card .hobby-icon { font-size: 2.2rem; margin-bottom: 0.6rem; display: block; }
.hobby-card h3 {
  font-family: 'Poppins', sans-serif;
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 0.3rem;
}
.hobby-card p { font-size: 0.78rem; color: var(--text-secondary); }

/* ── Photo Grid ── */
.photo-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.photo-placeholder {
  aspect-ratio: 4/3;
  background: var(--bg-secondary);
  border: 2px dashed var(--border);
  border-radius: 14px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  color: var(--text-secondary);
  font-size: 0.8rem;
  transition: all 0.3s;
  cursor: pointer;
  text-align: center;
  padding: 1rem;
}

.photo-placeholder:hover {
  border-color: var(--accent);
  background: rgba(168, 85, 247, 0.06);
  color: var(--accent-light);
  box-shadow: var(--glow-sm);
}

.photo-placeholder .photo-icon { font-size: 1.8rem; opacity: 0.4; }

/* ── Coming Soon ── */
.coming-soon {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 3rem 2rem;
  text-align: center;
}

.coming-soon .big-icon { font-size: 2.8rem; margin-bottom: 0.75rem; display: block; }

.coming-soon h3 {
  font-family: 'Poppins', sans-serif;
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
}

.coming-soon p { color: var(--text-secondary); font-size: 0.9rem; }

.badge {
  display: inline-block;
  padding: 0.25rem 0.8rem;
  background: rgba(168, 85, 247, 0.12);
  border: 1px solid rgba(168, 85, 247, 0.3);
  border-radius: 50px;
  font-size: 0.72rem;
  color: var(--accent-light);
  margin-top: 1rem;
  font-weight: 600;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

/* ── Keyboard Gallery ── */
.keyboard-toggle {
  cursor: pointer;
  position: relative;
}

.keyboard-toggle .expand-hint {
  display: block;
  font-size: 0.7rem;
  color: var(--accent-light);
  margin-top: 0.3rem;
  opacity: 0.7;
}

.keyboard-toggle.open .expand-hint {
  color: var(--accent-light);
  opacity: 1;
}

.keyboard-gallery {
  display: none;
  margin-top: 1rem;
}

.keyboard-gallery.open {
  display: block;
}

/* ── Video Grid ── */
.video-grid {
  display: grid;
  grid-template-columns: repeat(2, 280px);
  gap: 1rem;
}

.video-card {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.video-title {
  text-align: center;
  font-family: 'Poppins', sans-serif;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
}

.music-video {
  width: 100%;
  height: 180px;
  border-radius: 10px;
  border: 1px solid var(--accent);
  background: #000;
  object-fit: cover;
  box-shadow: var(--glow-sm);
  transition: box-shadow 0.3s;
}

.music-video:hover {
  box-shadow: var(--glow-md);
}

@media (max-width: 600px) {
  .video-grid { grid-template-columns: 1fr; }
}

/* ── Video Link Buttons ── */
.video-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
}

.video-link-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 12px;
  color: var(--text-primary);
  text-decoration: none;
  font-family: 'Poppins', sans-serif;
  font-size: 0.95rem;
  font-weight: 600;
  transition: all 0.25s;
}

.video-link-btn:hover {
  border-color: var(--accent);
  background: var(--bg-card);
  color: var(--accent-light);
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(168, 85, 247, 0.3), var(--glow-sm);
}

/* ── Prerequisites ── */
.prereq-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.prereq-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1.25rem;
}

.prereq-title {
  font-family: 'Poppins', sans-serif;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--accent-light);
  text-transform: uppercase;
  letter-spacing: 0.07em;
  margin-bottom: 0.6rem;
}

.code-inline {
  display: inline-block;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 5px;
  font-family: monospace;
  font-size: 0.72rem;
  color: var(--accent-light);
  padding: 0.15rem 0.4rem;
  word-break: break-all;
  margin-top: 0.25rem;
}

@media (max-width: 768px) {
  .prereq-grid { grid-template-columns: 1fr; }
}

/* ── Robotics Project Cards ── */
.robotics-video-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.robotics-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1rem;
}

.project-tag {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  font-family: 'Poppins', sans-serif;
  font-size: 0.7rem;
  font-weight: 700;
  padding: 0.18rem 0.65rem;
  border-radius: 20px;
  margin-bottom: 0.4rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.instructions-toggle {
  width: 100%;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--accent-light);
  font-family: 'Poppins', sans-serif;
  font-size: 0.8rem;
  font-weight: 600;
  padding: 0.45rem 1rem;
  cursor: pointer;
  transition: all 0.2s;
  margin-top: 0.25rem;
}

.instructions-toggle:hover {
  background: var(--bg-card);
  border-color: var(--accent);
  color: var(--accent);
}

.instructions-panel {
  display: none;
  flex-direction: column;
  gap: 0.65rem;
  margin-top: 0.75rem;
}

.instructions-panel.open {
  display: flex;
}

.project-section {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.8rem 1rem;
}

.project-section-title {
  font-family: 'Poppins', sans-serif;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-light);
  text-transform: uppercase;
  letter-spacing: 0.07em;
  margin-bottom: 0.5rem;
}

.project-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.project-list li {
  font-size: 0.84rem;
  color: var(--text-secondary);
  padding-left: 1.1rem;
  position: relative;
}

.project-list li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-size: 0.78rem;
}

.project-steps {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  counter-reset: step-counter;
}

.project-steps li {
  font-size: 0.84rem;
  color: var(--text-secondary);
  padding-left: 2rem;
  position: relative;
  counter-increment: step-counter;
  line-height: 1.5;
}

.project-steps li::before {
  content: counter(step-counter);
  position: absolute;
  left: 0;
  width: 1.35rem;
  height: 1.35rem;
  background: var(--accent);
  color: #fff;
  border-radius: 50%;
  font-size: 0.65rem;
  font-weight: 700;
  font-family: 'Poppins', sans-serif;
  display: flex;
  align-items: center;
  justify-content: center;
  top: 0.08rem;
}

.project-steps li strong {
  color: var(--text-primary);
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}

.project-learn-tag {
  background: rgba(168, 85, 247, 0.15);
  border: 1px solid rgba(168, 85, 247, 0.35);
  color: var(--accent-light);
  font-size: 0.71rem;
  font-weight: 600;
  padding: 0.18rem 0.6rem;
  border-radius: 20px;
  font-family: 'Poppins', sans-serif;
}

@media (max-width: 650px) {
  .robotics-video-grid {
    grid-template-columns: 1fr;
  }
}

/* ── Footer ── */
footer {
  text-align: center;
  padding: 2rem;
  border-top: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 0.82rem;
  margin-top: 2rem;
}

/* ── Fade-in animation ── */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ── Responsive ── */
@media (max-width: 900px) {
  .hobbies-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .hamburger { display: flex; }
  .photo-grid { grid-template-columns: repeat(2, 1fr); }
  .hobbies-grid { grid-template-columns: repeat(2, 1fr); }
  .hero { padding: 3rem 1.5rem 2.5rem; }
  .section { padding: 3rem 1.5rem; }
}

@media (max-width: 480px) {
  .photo-grid { grid-template-columns: 1fr; }
  .profile-section { flex-direction: column; align-items: center; text-align: center; }
  nav { padding: 0 1.25rem; }
}