/* ============================================================
   Lambda Symbolics -- Landing Page Styles
   ============================================================ */

:root {
  --bg:                 #050906;
  --bg-soft:            #0a130d;
  --panel:              #0a130f;
  --panel-strong:       #0d1a13;
  --line:               #224432;
  --line-subtle:        #1a3327;
  --text:               #e8ffe9;
  --muted:              #93b79d;
  --lisp-green:         #74ff9f;
  --lisp-green-strong:  #49e67d;
  --lisp-green-muted:   #2da056;
  --lisp-green-dim:     rgba(116, 255, 159, 0.08);
  --shadow:             rgba(9, 21, 14, 0.75);
  --glow:               rgba(116, 255, 159, 0.15);
  --font-body:          "Space Grotesk", "Segoe UI", sans-serif;
  --font-mono:          "JetBrains Mono", monospace;
}

/* ---- Reset ---- */

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 5rem;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  font-family: var(--font-body);
  background:
    radial-gradient(120% 120% at 90% -10%, #123122 0%, transparent 60%),
    radial-gradient(120% 120% at 10% 120%, #0d2418 0%, transparent 62%),
    var(--bg);
  color: var(--text);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* ---- Accessibility ---- */

.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  z-index: 1000;
  padding: 0.6rem 1.2rem;
  background: var(--lisp-green);
  color: #041008;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.85rem;
  text-decoration: none;
}

.skip-link:focus {
  top: 1rem;
}

/* ---- Background Effects ---- */

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(
    480px circle at var(--cursor-x, 50%) var(--cursor-y, 20%),
    rgba(116, 255, 159, 0.14) 0%,
    rgba(116, 255, 159, 0.05) 30%,
    transparent 62%
  );
  z-index: 0;
  transition: background 80ms ease;
}

.bg-grid,
.bg-noise {
  pointer-events: none;
  position: fixed;
  inset: 0;
  z-index: 0;
}

.bg-grid {
  background-image:
    linear-gradient(rgba(116, 255, 159, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(116, 255, 159, 0.04) 1px, transparent 1px);
  background-size: 40px 40px;
  mask-image: radial-gradient(ellipse 80% 70% at 50% 30%, black 40%, transparent 100%);
}

.bg-noise {
  opacity: 0.06;
  background-image: radial-gradient(rgba(255, 255, 255, 0.3) 0.6px, transparent 0.6px);
  background-size: 3px 3px;
  animation: noise-shift 220ms steps(2, end) infinite;
}

@keyframes noise-shift {
  0%   { transform: translate(0, 0); }
  100% { transform: translate(-1px, 1px); }
}

@media (prefers-reduced-motion: reduce) {
  .bg-noise {
    animation: none;
  }

  html {
    scroll-behavior: auto;
  }

  .js [data-reveal] {
    opacity: 1;
    transform: none;
  }
}

/* ---- Layout ---- */

.container {
  width: min(1120px, calc(100% - 3rem));
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

/* ---- Header ---- */

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.2rem 0;
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 0.7rem;
  color: inherit;
  text-decoration: none;
  transition: opacity 180ms ease;
}

.brand:hover {
  opacity: 0.8;
}

.brand-lambda {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  color: var(--lisp-green);
  line-height: 1;
}

.brand-name {
  font-size: 0.9rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 1.4rem;
}

.site-nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  position: relative;
  transition: color 180ms ease;
}

.site-nav a::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--lisp-green);
  transition: width 250ms ease;
}

.site-nav a:hover,
.site-nav a:focus-visible,
.site-nav a.is-active {
  color: var(--lisp-green);
}

.site-nav a:hover::after,
.site-nav a:focus-visible::after,
.site-nav a.is-active::after {
  width: 100%;
}

/* ---- Hero ---- */

.hero {
  padding: clamp(3rem, 10vw, 7rem) 0 clamp(2rem, 6vw, 4rem);
  max-width: 900px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.35rem 0.9rem;
  border: 1px solid var(--line);
  background: var(--lisp-green-dim);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--lisp-green);
  margin-bottom: 1.8rem;
}

.hero-badge-dot {
  width: 6px;
  height: 6px;
  background: var(--lisp-green);
  display: inline-block;
  animation: pulse-dot 2s ease-in-out infinite;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; }
  50%      { opacity: 0.3; }
}

.hero h1 {
  margin: 0;
  font-size: clamp(2.4rem, 6vw, 4.8rem);
  line-height: 1.02;
  letter-spacing: -0.02em;
  font-weight: 700;
}

.hero-typed {
  color: var(--lisp-green);
  display: inline;
}

.hero-typed::after {
  content: "";
  display: inline-block;
  width: 3px;
  height: 0.85em;
  background: var(--lisp-green);
  margin-left: 2px;
  vertical-align: text-bottom;
  animation: blink-cursor 800ms steps(1) infinite;
}

@keyframes blink-cursor {
  0%, 100% { opacity: 1; }
  50%      { opacity: 0; }
}

.hero-copy {
  margin: 1.8rem 0 0;
  color: var(--muted);
  max-width: 58ch;
  font-size: clamp(1rem, 2.2vw, 1.15rem);
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-top: 2.4rem;
}

.hero-stats {
  display: flex;
  gap: 2.4rem;
  margin-top: 3.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--line-subtle);
}

.stat {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.stat-value {
  font-family: var(--font-mono);
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1;
}

.stat-label {
  font-size: 0.75rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

/* ---- Sections ---- */

.section {
  padding: clamp(3rem, 8vw, 5.5rem) 0;
  border-top: 1px solid var(--line-subtle);
}

.section-header {
  max-width: 640px;
  margin-bottom: 2.8rem;
}

.section-kicker {
  margin: 0 0 0.8rem;
  font-family: var(--font-mono);
  color: var(--lisp-green);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-size: 0.72rem;
}

.section-header h2 {
  margin: 0;
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  line-height: 1.1;
  letter-spacing: -0.01em;
}

.section-subtitle {
  margin: 1rem 0 0;
  color: var(--muted);
  font-size: clamp(0.95rem, 2vw, 1.1rem);
  line-height: 1.7;
}

/* ---- Feature Cards (Hiisi) ---- */

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--line-subtle);
  border: 1px solid var(--line-subtle);
}

.feature-card {
  background: linear-gradient(180deg, rgba(13, 26, 19, 0.95) 0%, rgba(8, 15, 11, 0.98) 100%);
  padding: 1.8rem;
  transition: background 300ms ease;
}

.feature-card:hover {
  background: linear-gradient(180deg, rgba(16, 32, 23, 0.98) 0%, rgba(10, 20, 14, 0.98) 100%);
}

.feature-icon {
  width: 2rem;
  height: 2rem;
  color: var(--lisp-green);
  margin-bottom: 1rem;
}

.feature-icon svg {
  width: 100%;
  height: 100%;
}

.feature-card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
  font-weight: 600;
}

.feature-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.6;
}

.product-cta {
  display: flex;
  align-items: center;
  gap: 1.2rem;
  margin-top: 2.2rem;
}

.product-cta-note {
  color: var(--muted);
  font-size: 0.82rem;
  font-family: var(--font-mono);
}

/* ---- Stack Cards ---- */

.stack-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--line-subtle);
  border: 1px solid var(--line-subtle);
}

.stack-card {
  background: linear-gradient(180deg, rgba(13, 26, 19, 0.95) 0%, rgba(8, 15, 11, 0.98) 100%);
  padding: 1.6rem;
  transition: background 300ms ease;
}

.stack-card:hover {
  background: linear-gradient(180deg, rgba(16, 32, 23, 0.98) 0%, rgba(10, 20, 14, 0.98) 100%);
}

.stack-card-header {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  margin-bottom: 0.8rem;
}

.stack-card-icon {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--lisp-green);
  background: var(--lisp-green-dim);
  border: 1px solid var(--line);
  width: 2.2rem;
  height: 2.2rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.stack-card h3 {
  margin: 0;
  font-size: 1rem;
  font-weight: 600;
}

.stack-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.85rem;
  line-height: 1.6;
}

/* ---- Course Section ---- */

.course-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  align-items: start;
}

.course-module h3 {
  margin: 0 0 1rem;
  font-size: 1.1rem;
}

.course-list {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.7;
}

.course-list li {
  margin: 0.5rem 0;
}

.course-list li::marker {
  color: var(--lisp-green-muted);
}

/* ---- Terminal ---- */

.terminal {
  border: 1px solid var(--line);
  background: #08120d;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  overflow: hidden;
}

.terminal-bar {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.6rem 1rem;
  border-bottom: 1px solid var(--line-subtle);
  background: rgba(13, 26, 19, 0.6);
}

.terminal-dot {
  width: 8px;
  height: 8px;
  background: var(--line);
  display: inline-block;
}

.terminal-title {
  margin-left: 0.5rem;
  color: var(--muted);
  font-size: 0.72rem;
}

.terminal-body {
  padding: 1rem 1.2rem;
}

.terminal-body p {
  margin: 0;
}

.terminal-body p + p {
  margin-top: 0.35rem;
}

.terminal-prompt {
  color: var(--lisp-green);
  font-weight: 600;
}

.terminal-line {
  color: var(--muted);
}

.terminal-val {
  color: var(--lisp-green);
}

.terminal-cursor {
  animation: blink-cursor 800ms steps(1) infinite;
  color: var(--lisp-green);
}

/* ---- About ---- */

.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: start;
}

.about-text p {
  color: var(--muted);
  margin: 0 0 1.2rem;
  line-height: 1.7;
  font-size: 0.95rem;
}

.about-lead {
  font-size: 1.05rem !important;
  color: var(--text) !important;
}

.about-lead strong {
  color: var(--lisp-green);
}

.about-values {
  display: flex;
  flex-direction: column;
  gap: 1.4rem;
}

.value-item {
  padding: 1.2rem;
  border: 1px solid var(--line-subtle);
  background: linear-gradient(180deg, rgba(13, 26, 19, 0.6) 0%, rgba(8, 15, 11, 0.6) 100%);
  transition: border-color 300ms ease;
}

.value-item:hover {
  border-color: var(--line);
}

.value-item h3 {
  margin: 0 0 0.35rem;
  font-size: 0.92rem;
  font-weight: 600;
}

.value-item p {
  margin: 0;
  color: var(--muted);
  font-size: 0.85rem;
  line-height: 1.6;
}

/* ---- Contact ---- */

.section-contact {
  padding-bottom: 2rem;
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--line-subtle);
  border: 1px solid var(--line-subtle);
}

.contact-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.6rem;
  padding: 1.6rem;
  background: linear-gradient(180deg, rgba(13, 26, 19, 0.95) 0%, rgba(8, 15, 11, 0.98) 100%);
  text-decoration: none;
  color: var(--text);
  transition: background 300ms ease;
}

.contact-card:hover {
  background: linear-gradient(180deg, rgba(16, 32, 23, 0.98) 0%, rgba(10, 20, 14, 0.98) 100%);
}

.contact-icon {
  width: 1.4rem;
  height: 1.4rem;
  color: var(--lisp-green);
}

.contact-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.contact-detail {
  font-size: 0.95rem;
  color: var(--text);
}

.contact-card:hover .contact-detail {
  color: var(--lisp-green);
}

/* ---- Buttons ---- */

.button {
  display: inline-flex;
  justify-content: center;
  align-items: center;
  gap: 0.5rem;
  min-height: 2.9rem;
  padding: 0 1.3rem;
  border: 1px solid var(--line);
  text-decoration: none;
  color: var(--text);
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
  font-size: 0.82rem;
  text-transform: uppercase;
  transition:
    transform 150ms ease,
    border-color 150ms ease,
    background 150ms ease,
    box-shadow 150ms ease;
}

.button:hover,
.button:focus-visible {
  transform: translateY(-1px);
}

.button-icon {
  font-size: 1.05rem;
  line-height: 1;
}

.button-primary {
  background: linear-gradient(180deg, var(--lisp-green) 0%, var(--lisp-green-strong) 100%);
  color: #041008;
  border-color: var(--lisp-green);
  font-weight: 700;
}

.button-primary:hover,
.button-primary:focus-visible {
  background: linear-gradient(180deg, #96ffb6 0%, #62ef92 100%);
  box-shadow: 0 0 20px rgba(116, 255, 159, 0.3);
}

.button-secondary {
  background: rgba(10, 20, 14, 0.75);
}

.button-secondary:hover,
.button-secondary:focus-visible {
  border-color: var(--lisp-green-muted);
  background: rgba(12, 25, 17, 0.95);
  box-shadow: 0 0 15px rgba(116, 255, 159, 0.1);
}

/* ---- Text Links ---- */

.text-link {
  color: var(--lisp-green);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  margin-top: 1rem;
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-size: 0.79rem;
  transition: gap 200ms ease;
}

.text-link:hover,
.text-link:focus-visible {
  text-decoration: underline;
  gap: 0.6rem;
}

/* ---- Footer ---- */

.site-footer {
  border-top: 1px solid var(--line);
  margin-top: 2rem;
  padding: 2rem 0 2.5rem;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
}

.footer-left,
.footer-right {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.footer-right {
  text-align: right;
}

.site-footer p {
  margin: 0;
  color: var(--muted);
  font-size: 0.82rem;
}

.footer-brand {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  font-size: 0.85rem !important;
  color: var(--text) !important;
}

.footer-brand .brand-lambda {
  font-size: 1.1rem;
}

.footer-tagline {
  font-family: var(--font-mono);
  font-size: 0.72rem !important;
  letter-spacing: 0.04em;
}

/* ---- Scroll Reveal ---- */

.js [data-reveal] {
  opacity: 0;
  transform: translateY(20px);
}

.js [data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
  transition:
    opacity 600ms cubic-bezier(0.22, 1, 0.36, 1),
    transform 600ms cubic-bezier(0.22, 1, 0.36, 1);
}

.js [data-reveal][data-delay="1"] { transition-delay: 150ms; }
.js [data-reveal][data-delay="2"] { transition-delay: 300ms; }
.js [data-reveal][data-delay="3"] { transition-delay: 450ms; }
.js [data-reveal][data-delay="4"] { transition-delay: 600ms; }
.js [data-reveal][data-delay="5"] { transition-delay: 750ms; }

/* ---- Responsive: Tablet ---- */

@media (max-width: 900px) {
  .site-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.9rem;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .stack-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .course-content {
    grid-template-columns: 1fr;
  }

  .about-content {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .contact-grid {
    grid-template-columns: 1fr;
  }

  .hero-stats {
    flex-wrap: wrap;
    gap: 1.5rem;
  }
}

/* ---- Responsive: Mobile ---- */

@media (max-width: 640px) {
  .container {
    width: min(1120px, calc(100% - 1.4rem));
  }

  .site-nav {
    width: 100%;
    justify-content: flex-start;
    flex-wrap: wrap;
    gap: 0.5rem 1rem;
  }

  .site-nav a {
    font-size: 0.72rem;
  }

  .hero h1 {
    font-size: clamp(1.8rem, 8vw, 2.6rem);
  }

  .hero-stats {
    gap: 1.2rem;
  }

  .stat-value {
    font-size: 1.4rem;
  }

  .feature-card,
  .stack-card,
  .contact-card {
    padding: 1.2rem;
  }

  .stack-grid {
    grid-template-columns: 1fr;
  }

  .site-footer {
    flex-direction: column;
    gap: 1rem;
  }

  .footer-right {
    text-align: left;
  }
}