:root {
  --black: #000000;
  --white: #ffffff;
  --grey-900: #1a1a1a;
  --grey-700: #3a3a3a;
  --grey-500: #777777;
  --grey-300: #c9c9c9;
  --grey-100: #f2f2f2;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Poppins", sans-serif;
  background: var(--black);
  color: var(--white);
  line-height: 1.6;
}

/* ---------- Fixed left-middle navigation ---------- */
.side-nav {
  position: fixed;
  left: 24px;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  flex-direction: column;
  gap: 20px;
  z-index: 100;
}

.side-nav .nav-link {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--grey-300);
  text-decoration: none;
  font-size: 13px;
  letter-spacing: 0.5px;
  opacity: 0.75;
  cursor: pointer; /* pointer cursor on nav links */
  transition:
    color 0.3s,
    opacity 0.3s;
}

.side-nav .nav-link .dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--grey-500);
  transition:
    background 0.3s,
    transform 0.3s,
    box-shadow 0.3s;
}

.side-nav .nav-link:hover,
.side-nav .nav-link.active {
  color: var(--white);
  opacity: 1;
}

.side-nav .nav-link:hover {
  color: #ffe600;
  opacity: 1;
  text-shadow:
    0 0 8px rgba(255, 230, 0, 0.9),
    0 0 16px rgba(255, 230, 0, 0.6);
}

.side-nav .nav-link.active .dot {
  background: #ffe600;
  box-shadow:
    0 0 12px rgba(255, 230, 0, 0.9),
    0 0 20px rgba(255, 230, 0, 0.5);
  transform: scale(1.4);
}

/* ---------- Hamburger toggle (hidden on desktop) ---------- */
.menu-toggle {
  display: none;
  position: fixed;
  top: 20px;
  left: 20px;
  z-index: 110;
  flex-direction: column;
  justify-content: center;
  gap: 6px;
  width: 44px;
  height: 44px;
  padding: 10px;
  background: rgba(0, 0, 0, 0.6);
  border: 1px solid var(--grey-500);
  border-radius: 8px;
  cursor: pointer;
}

.menu-toggle span {
  width: 100%;
  height: 2px;
  background: var(--white);
  transition:
    transform 0.3s,
    opacity 0.3s;
}

/* ---------- Backdrop overlay (mobile only) ---------- */
.overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  z-index: 105;
}

.overlay.show {
  display: block;
}

/* ---------- Hero ---------- */
.hero {
  min-height: 100vh;
  background:
    linear-gradient(
      to bottom,
      rgba(0, 0, 0, 0.35),
      rgba(0, 0, 0, 0.75) 60%,
      var(--black)
    ),
    url("https://images.unsplash.com/photo-1509099836639-18ba1795216d?auto=format&fit=crop&w=1600&q=80")
      center/cover no-repeat;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 0 40px;
}

.hero-content h1 {
  font-size: clamp(2.5rem, 7vw, 5.5rem);
  font-weight: 700;
  letter-spacing: 1px;
}

.hero-content p {
  margin-top: 16px;
  font-size: clamp(1rem, 2.5vw, 1.5rem);
  font-weight: 300;
  color: var(--grey-300);
}

.btn {
  display: inline-block;
  margin-top: 40px;
  padding: 14px 36px;
  border: 1px solid var(--white);
  color: var(--white);
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 2px;
  font-size: 13px;
  transition:
    background 0.3s,
    color 0.3s;
}

.btn:hover {
  background: var(--white);
  color: var(--black);
}

/* ---------- Sections ---------- */
main {
  /* top 0 | right 60 | bottom 220 | left 220  → clears the fixed left nav */
  padding: 0 60px 220px 220px;
}

.section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 90px 0;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 600;
  margin-bottom: 24px;
  position: relative;
  padding-bottom: 14px;
}

.section-title::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 60px;
  height: 3px;
  background: var(--white);
}

.section-sub {
  color: var(--grey-300);
  margin-bottom: 40px;
}

/* ---------- About ---------- */
.about-block,
.collaborations {
  margin-bottom: 48px;
}

.about-text {
  color: var(--grey-300);
  max-width: 780px;
  font-size: 1.05rem;
}

.about-intro {
  color: var(--grey-100);
  font-size: 1.1rem;
  max-width: 780px;
  margin-bottom: 18px;
}

.about-subtitle {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 14px;
  color: var(--white);
}

.collab-list {
  margin: 18px 0 18px 20px;
  color: var(--grey-300);
  max-width: 780px;
}

.collab-list li {
  margin-bottom: 12px;
}

.collab-list strong {
  color: var(--white);
}

/* ---------- Grids ---------- */
.grid {
  display: grid;
  gap: 24px;
}

.grid-3 {
  grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

/* Testimonial cards */
.t-card {
  background: var(--grey-900);
  border: 1px solid var(--grey-700);
  padding: 28px 24px;
  border-radius: 10px;
  transition:
    transform 0.3s,
    border-color 0.3s;
}

.t-card:hover {
  transform: translateY(-4px);
  border-color: var(--grey-500);
  box-shadow:
    0 0 16px rgba(255, 230, 0, 0.6),
    0 0 30px rgba(255, 230, 0, 0.3);
}

.t-card blockquote {
  font-size: 0.95rem;
  color: var(--grey-300);
  font-style: italic;
  margin-bottom: 18px;
}

.t-card .t-author {
  color: var(--white);
  font-weight: 600;
  font-size: 0.9rem;
}

.t-card .t-role {
  color: var(--grey-500);
  font-size: 0.8rem;
}

/* Resource cards */
.r-card {
  background: var(--grey-900);
  border: 1px solid var(--grey-700);
  border-radius: 10px;
  padding: 26px 20px;
  text-align: center;
  text-decoration: none;
  color: var(--white);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  transition:
    transform 0.3s,
    border-color 0.3s,
    box-shadow 0.3s;
}

.r-card .r-emoji {
  font-size: 2rem;
}

.r-card .r-name {
  font-weight: 600;
  font-size: 0.95rem;
}

.r-card .r-desc {
  color: var(--grey-500);
  font-size: 0.8rem;
}

/* Fixed invalid var(#ffe600) → real color, and made the glow yellow */
.r-card:hover {
  transform: translateY(-4px);
  border-color: #ffe600;
  box-shadow:
    0 0 16px rgba(255, 230, 0, 0.6),
    0 0 30px rgba(255, 230, 0, 0.3);
}

/* ---------- Footer ---------- */
.footer {
  background: var(--grey-900);
  border-top: 1px solid var(--grey-700);
  padding: 60px 40px;
  text-align: center;
}

.footer-name {
  font-weight: 600;
  font-size: 1.3rem;
  margin-bottom: 6px;
}

.footer-tag {
  color: var(--grey-500);
  font-style: italic;
  margin-bottom: 24px;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 40px;
  margin-bottom: 30px;
  flex-wrap: wrap;
}

.social-link {
  color: var(--grey-300);
  display: inline-flex;
  transition:
    color 0.3s,
    transform 0.3s,
    filter 0.3s;
}

.social-link:hover {
  color: #ffe600;
  transform: translateY(-2px);
  filter: drop-shadow(0 0 8px rgba(255, 230, 0, 0.8));
}

.social-link svg {
  display: block;
}

.footer-copy {
  color: var(--grey-500);
  font-size: 0.8rem;
}

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .grid-3 {
    grid-template-columns: 1fr;
  }
  /* Remove the left clearance on mobile since the nav becomes a drawer */
  main {
    padding: 0 30px 60px;
  }

  .menu-toggle {
    display: flex;
  }

  .overlay.show {
    display: block;
  }

  .side-nav {
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    width: 50vw; /* about half the viewport width */
    transform: translateX(-100%);
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
    gap: 26px;
    background: var(--grey-900);
    border-right: 1px solid var(--grey-700);
    padding: 0 30px;
    z-index: 100;
    transition: transform 0.35s ease;
  }

  .side-nav.open {
    transform: translateX(0);
  }

  /* Show only the label text in the drawer (keeps the dot a proper circle) */
  .side-nav .nav-link span:last-child {
    display: inline;
  }

  /* Animate hamburger into an X when open */
  .menu-toggle.open span:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
  }
  .menu-toggle.open span:nth-child(2) {
    opacity: 0;
  }
  .menu-toggle.open span:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
  }
}

@media (max-width: 520px) {
  .grid-4 {
    grid-template-columns: 1fr;
  }
}