/* ============================================================
   Amir Koutahi — personal site
   Sleek dark-tech theme
   ============================================================ */

:root {
  --bg:        #0a0e14;
  --bg-soft:   #0e131c;
  --panel:     #11171f;
  --panel-2:   #151c27;
  --border:    #1f2937;
  --border-hi: #2b3a4f;
  --text:      #e6edf3;
  --text-dim:  #9aa7b5;
  --muted:     #6b7a8d;
  --accent:    #64ffda;
  --accent-2:  #7c93ff;
  --accent-dim:#64ffda1a;
  --danger:    #ff7b72;
  --radius:    14px;
  --maxw:      1080px;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* Subtle grid + glow backdrop */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 48px 48px;
  opacity: 0.18;
  z-index: -2;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 30%, transparent 75%);
}
body::after {
  content: "";
  position: fixed;
  top: -20%;
  left: 50%;
  transform: translateX(-50%);
  width: 900px;
  height: 600px;
  background: radial-gradient(circle, var(--accent-dim) 0%, transparent 70%);
  filter: blur(40px);
  z-index: -1;
  pointer-events: none;
}

a { color: var(--accent); text-decoration: none; transition: color .2s; }
a:hover { color: #fff; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- Nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(12px);
  background: #0a0e14cc;
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: .5px;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 10px;
}
.brand .dot { color: var(--accent); }
.brand:hover { color: #fff; }
.nav-links { display: flex; gap: 6px; align-items: center; }
.nav-links a {
  font-family: var(--mono);
  font-size: 13.5px;
  color: var(--text-dim);
  padding: 7px 13px;
  border-radius: 8px;
  transition: all .2s;
}
.nav-links a:hover { color: var(--text); background: var(--panel); }
.nav-links a.active { color: var(--accent); }
.nav-toggle {
  display: none;
  background: none; border: 1px solid var(--border);
  color: var(--text); border-radius: 8px;
  padding: 7px 10px; cursor: pointer; font-size: 16px;
}

/* ---------- Hero ---------- */
.hero { padding: 90px 0 60px; }
.eyebrow {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--accent);
  letter-spacing: 1px;
  margin-bottom: 18px;
  display: inline-flex;
  align-items: center;
  gap: 9px;
}
.eyebrow .pulse {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 0 var(--accent);
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0% { box-shadow: 0 0 0 0 #64ffda66; }
  70% { box-shadow: 0 0 0 10px #64ffda00; }
  100% { box-shadow: 0 0 0 0 #64ffda00; }
}
.hero h1 {
  font-size: clamp(2.4rem, 6vw, 4rem);
  line-height: 1.05;
  margin: 0 0 18px;
  font-weight: 800;
  letter-spacing: -1.5px;
}
.hero h1 .grad {
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero p.lead {
  font-size: 1.15rem;
  color: var(--text-dim);
  max-width: 640px;
  margin: 0 0 32px;
}
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; }

.btn {
  font-family: var(--mono);
  font-size: 14px;
  padding: 12px 22px;
  border-radius: 10px;
  border: 1px solid var(--border-hi);
  background: var(--panel);
  color: var(--text);
  cursor: pointer;
  transition: all .2s;
  display: inline-flex;
  align-items: center;
  gap: 9px;
}
.btn:hover { border-color: var(--accent); color: #fff; transform: translateY(-2px); }
.btn.primary {
  background: var(--accent);
  color: #06281f;
  border-color: var(--accent);
  font-weight: 600;
}
.btn.primary:hover { background: #7dffe2; color: #04201a; box-shadow: 0 8px 30px -8px var(--accent); }

/* ---------- Section ---------- */
.section { padding: 56px 0; }
.section-head { margin-bottom: 36px; }
.section-head .tag {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--accent);
  letter-spacing: .5px;
}
.section-head h2 {
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  margin: 8px 0 10px;
  font-weight: 700;
  letter-spacing: -.5px;
}
.section-head p { color: var(--text-dim); max-width: 620px; margin: 0; }

/* ---------- Cards grid: What I do ---------- */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}
.feature {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px;
  transition: all .25s;
  position: relative;
  overflow: hidden;
}
.feature::before {
  content: "";
  position: absolute; inset: 0;
  background: linear-gradient(135deg, var(--accent-dim), transparent 40%);
  opacity: 0; transition: opacity .25s;
}
.feature:hover { border-color: var(--border-hi); transform: translateY(-4px); }
.feature:hover::before { opacity: 1; }
.feature .icon {
  font-family: var(--mono);
  font-size: 22px;
  color: var(--accent);
  margin-bottom: 14px;
  display: inline-flex;
  width: 46px; height: 46px;
  align-items: center; justify-content: center;
  background: var(--accent-dim);
  border-radius: 10px;
}
.feature h3 { margin: 0 0 8px; font-size: 1.1rem; position: relative; }
.feature p { margin: 0; color: var(--text-dim); font-size: .95rem; position: relative; }

/* ---------- Explore cards ---------- */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.xcard {
  display: block;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px;
  transition: all .25s;
  color: var(--text);
}
.xcard:hover { border-color: var(--accent); transform: translateY(-4px); color: var(--text); }
.xcard .k { font-family: var(--mono); font-size: 12px; color: var(--accent); }
.xcard h3 { margin: 10px 0 8px; font-size: 1.3rem; display: flex; align-items: center; gap: 8px; }
.xcard:hover h3 .arr { transform: translateX(4px); }
.xcard .arr { transition: transform .2s; color: var(--accent); }
.xcard p { margin: 0; color: var(--text-dim); font-size: .95rem; }

/* ---------- Filters ---------- */
.filters {
  display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 28px;
}
.filter-btn {
  font-family: var(--mono);
  font-size: 12.5px;
  padding: 7px 14px;
  border-radius: 20px;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text-dim);
  cursor: pointer;
  transition: all .2s;
}
.filter-btn:hover { border-color: var(--border-hi); color: var(--text); }
.filter-btn.active { background: var(--accent); color: #06281f; border-color: var(--accent); font-weight: 600; }

/* ---------- Project cards ---------- */
.projects { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.pcard {
  display: flex;
  flex-direction: column;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: all .25s;
  color: var(--text);
  position: relative;
}
.pcard:hover { border-color: var(--border-hi); transform: translateY(-4px); color: var(--text); box-shadow: 0 14px 40px -20px #000; }
.pcard .cat {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}
.pcard h3 { margin: 0 0 10px; font-size: 1.18rem; line-height: 1.3; }
.pcard p { margin: 0 0 18px; color: var(--text-dim); font-size: .92rem; flex: 1; }
.tags { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 16px; }
.tag-pill {
  font-family: var(--mono);
  font-size: 11px;
  padding: 4px 9px;
  border-radius: 6px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  color: var(--text-dim);
}
.pcard .open {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--accent);
  display: inline-flex;
  align-items: center;
  gap: 7px;
}
.pcard:hover .open .arr { transform: translateX(4px); }
.pcard .open .arr { transition: transform .2s; }

/* ---------- Tutorial notes accordion ---------- */
.course {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 16px;
  overflow: hidden;
}
.course-head {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 22px 24px;
  cursor: pointer;
  user-select: none;
}
.course-head:hover { background: var(--panel-2); }
.course-code {
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--accent);
  background: var(--accent-dim);
  padding: 6px 11px;
  border-radius: 7px;
  flex-shrink: 0;
}
.course-meta { flex: 1; }
.course-meta h3 { margin: 0; font-size: 1.15rem; }
.course-meta span { font-size: .85rem; color: var(--muted); font-family: var(--mono); }
.chev { color: var(--text-dim); transition: transform .3s; font-size: 14px; }
.course.open .chev { transform: rotate(180deg); }
.course-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height .35s ease;
}
.course.open .course-body { max-height: 400px; }
.weeks {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(110px, 1fr));
  gap: 10px;
  padding: 4px 24px 24px;
}
.week {
  font-family: var(--mono);
  font-size: 13px;
  text-align: center;
  padding: 11px;
  border-radius: 9px;
  border: 1px solid var(--border);
  background: var(--panel-2);
  color: var(--text-dim);
  transition: all .2s;
  cursor: pointer;
}
.week:hover { border-color: var(--accent); color: var(--accent); background: var(--accent-dim); }
.week.soon { opacity: .45; cursor: not-allowed; }
.week.soon:hover { border-color: var(--border); color: var(--text-dim); background: var(--panel-2); }

/* ---------- About ---------- */
.about-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px;
}
.about-card p { color: var(--text-dim); margin: 0 0 16px; }
.about-card p:last-child { margin-bottom: 0; }

/* ---------- Contact ---------- */
.contact-grid { display: flex; flex-wrap: wrap; gap: 14px; }
.contact-card {
  flex: 1 1 220px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px;
  transition: all .25s;
  color: var(--text);
}
.contact-card:hover { border-color: var(--accent); transform: translateY(-4px); color: var(--text); }
.contact-card .k { font-family: var(--mono); font-size: 12px; color: var(--muted); }
.contact-card .v { font-size: 1rem; margin-top: 6px; word-break: break-all; }

/* ---------- Footer ---------- */
.footer {
  border-top: 1px solid var(--border);
  margin-top: 60px;
  padding: 40px 0;
}
.footer-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}
.footer .who { font-family: var(--mono); font-size: 13px; color: var(--text-dim); }
.footer .who strong { color: var(--text); }
.footer-links { display: flex; gap: 18px; }
.footer-links a { font-family: var(--mono); font-size: 13px; color: var(--text-dim); }
.footer-links a:hover { color: var(--accent); }

/* ---------- Reveal animation ---------- */
.reveal { opacity: 0; transform: translateY(20px); transition: opacity .6s, transform .6s; }
.reveal.in { opacity: 1; transform: none; }

/* ---------- Responsive ---------- */
@media (max-width: 820px) {
  .grid-3 { grid-template-columns: 1fr; }
  .grid-2, .projects { grid-template-columns: 1fr; }
  .nav-links {
    position: absolute;
    top: 100%; left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    background: var(--bg-soft);
    border-bottom: 1px solid var(--border);
    padding: 10px;
    gap: 4px;
    display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 11px 14px; }
  .nav-toggle { display: block; }
  .hero { padding: 60px 0 40px; }
}