/* ============================================================
   Vibe Coding Basics — Course Companion Site
   Clean light theme · single accent · no gradients
   ============================================================ */

:root {
  --bg:            #ffffff;
  --bg-alt:        #f7f8fa;
  --surface:       #ffffff;
  --border:        #e6e8ec;
  --border-strong: #d3d7de;

  --text:          #0f1729;
  --text-body:     #46506a;
  --text-muted:    #6b7488;

  --accent:        #2563eb;
  --accent-dark:   #1d4ed8;
  --accent-tint:   #eef4ff;
  --accent-border: #cfe0ff;

  --amber:         #b45309;
  --amber-tint:    #fef7ec;
  --amber-border:  #f3d9a8;

  --code-bg:       #0d1117;

  --radius:        14px;
  --radius-lg:     20px;
  --maxw:          1120px;

  --shadow-sm:     0 1px 2px rgba(15, 23, 41, 0.06);
  --shadow:        0 1px 3px rgba(15, 23, 41, 0.08), 0 12px 28px -14px rgba(15, 23, 41, 0.14);

  --font-display:  "Space Grotesk", "Inter", system-ui, sans-serif;
  --font-body:     "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono:     "JetBrains Mono", "SF Mono", ui-monospace, Menlo, monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 88px; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text-body);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .001ms !important; transition-duration: .001ms !important; }
}

img, svg { max-width: 100%; }

.container { width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: 24px; }

.skip-link {
  position: absolute; left: -999px; top: 0; z-index: 999;
  background: var(--accent); color: #fff; padding: 10px 16px; border-radius: 0 0 10px 0;
}
.skip-link:focus { left: 0; }

/* ---------- Typography ---------- */
h1, h2, h3 { font-family: var(--font-display); font-weight: 700; line-height: 1.12; letter-spacing: -0.02em; margin: 0; color: var(--text); }
h2 { font-size: clamp(1.75rem, 3.6vw, 2.6rem); }
h3 { font-size: 1.15rem; letter-spacing: -0.01em; }
p { margin: 0 0 1rem; }
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-dark); }
strong { color: var(--text); font-weight: 600; }

.accent { color: var(--accent); }

.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.72rem; letter-spacing: 0.24em; text-transform: uppercase;
  color: var(--accent); margin: 0 0 1.3rem; font-weight: 500;
}
.kicker {
  font-family: var(--font-mono);
  font-size: 0.72rem; letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--text-muted); margin: 0 0 0.85rem; font-weight: 500;
}
.kicker--center { text-align: center; }
.muted { color: var(--text-muted); }

/* ---------- Buttons ---------- */
.btn {
  --pad-y: 13px; --pad-x: 24px;
  display: inline-flex; align-items: center; justify-content: center; gap: .5em;
  padding: var(--pad-y) var(--pad-x);
  border-radius: 10px;
  font-family: var(--font-display); font-weight: 600; font-size: 0.96rem;
  letter-spacing: -0.01em; cursor: pointer; border: 1px solid transparent;
  transition: transform .16s ease, box-shadow .2s ease, background .2s ease, border-color .2s ease;
  white-space: nowrap;
}
.btn--primary { background: var(--accent); color: #fff; box-shadow: var(--shadow-sm); }
.btn--primary:hover { background: var(--accent-dark); color: #fff; transform: translateY(-1px); box-shadow: var(--shadow); }
.btn--ghost { background: var(--surface); color: var(--text); border-color: var(--border-strong); }
.btn--ghost:hover { background: var(--bg-alt); color: var(--text); border-color: var(--text-muted); transform: translateY(-1px); }
.btn--sm { --pad-y: 8px; --pad-x: 16px; font-size: 0.84rem; }
.btn--lg { --pad-y: 15px; --pad-x: 30px; font-size: 1.02rem; }

/* ---------- Nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color .25s ease, box-shadow .25s ease;
}
.nav.is-stuck { border-bottom-color: var(--border); box-shadow: 0 1px 12px rgba(15, 23, 41, 0.05); }
.nav__inner { display: flex; align-items: center; gap: 22px; height: 64px; }
.nav__brand { display: flex; align-items: center; gap: 10px; color: var(--text); font-family: var(--font-display); font-weight: 700; }
.nav__logo {
  font-family: var(--font-mono); color: var(--accent);
  background: var(--accent-tint); border: 1px solid var(--accent-border);
  width: 32px; height: 32px; display: grid; place-items: center; border-radius: 8px; font-size: .85rem;
}
.nav__brandtext { font-size: 0.95rem; letter-spacing: -0.01em; }
.nav__brandtext span { color: var(--text-muted); font-weight: 500; }

.nav__links { display: flex; gap: 20px; margin-left: auto; }
.nav__links a {
  color: var(--text-muted); font-size: 0.85rem; font-weight: 500;
  padding: 6px 2px; position: relative; transition: color .18s ease;
}
.nav__links a:hover { color: var(--text); }
.nav__links a.is-active { color: var(--text); }
.nav__links a.is-active::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -2px; height: 2px;
  background: var(--accent); border-radius: 2px;
}

.nav__actions { display: flex; align-items: center; gap: 10px; }
.nav__cta { opacity: 0; transform: translateX(6px); pointer-events: none; transition: opacity .25s ease, transform .25s ease; }
.nav__cta.is-visible { opacity: 1; transform: none; pointer-events: auto; }

.nav__toggle { display: none; flex-direction: column; gap: 5px; background: none; border: 0; cursor: pointer; padding: 8px; }
.nav__toggle span { width: 22px; height: 2px; background: var(--text); border-radius: 2px; transition: transform .22s ease, opacity .18s ease; }
.nav__toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav__toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav__toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- Sections ---------- */
.section { padding: clamp(60px, 8vw, 108px) 0; position: relative; }
.section--alt { background: var(--bg-alt); border-block: 1px solid var(--border); }
.section__head { max-width: 720px; margin-bottom: 48px; }
.section__intro { color: var(--text-muted); font-size: 1.1rem; margin-top: 0.9rem; }
.body-wide { max-width: 720px; color: var(--text-body); }

/* ---------- Reveal animation ---------- */
.reveal { opacity: 0; transform: translateY(16px); transition: opacity .5s ease, transform .5s ease; }
.reveal.in-view { opacity: 1; transform: none; }

/* ============================================================
   HERO
   ============================================================ */
.hero { padding: clamp(44px, 6vw, 84px) 0 clamp(56px, 8vw, 96px); }
.hero__bg { display: none; }
.hero__grid {
  display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 56px; align-items: center;
}
.hero__title { font-size: clamp(2rem, 5vw, 3.6rem); margin-bottom: 1.5rem; }
.hero__lede { color: var(--text-body); font-size: 1.02rem; max-width: 42ch; }
.hero__lede p { margin-bottom: .85rem; }
.hero__pull { color: var(--text); font-size: 1.06rem; border-left: 3px solid var(--accent); padding-left: 16px; }
.hero__ctas { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 1.9rem; }

/* Hero visual */
.hero__visual { position: relative; display: grid; gap: 16px; }
.hero__art {
  margin: 0; border-radius: var(--radius); overflow: hidden;
  border: 1px solid var(--border); box-shadow: var(--shadow);
}
.hero__art img { display: block; width: 100%; height: auto; }

.terminal {
  background: var(--code-bg); border: 1px solid #1e2430; border-radius: 12px;
  overflow: hidden; box-shadow: var(--shadow); font-family: var(--font-mono); font-size: .78rem;
}
.terminal__bar {
  display: flex; align-items: center; gap: 7px; padding: 10px 14px;
  background: #161b22; border-bottom: 1px solid #1e2430;
}
.dot { width: 10px; height: 10px; border-radius: 50%; }
.dot--r { background: #ff5f57; } .dot--y { background: #febc2e; } .dot--g { background: #28c840; }
.terminal__title { margin-left: 8px; color: #6b7488; font-size: .72rem; }
.terminal__body { padding: 14px 16px; display: grid; gap: 6px; line-height: 1.5; }
.terminal__body p { margin: 0; color: #9aa4b8; }
.c-orange { color: #ff9d5c; } .c-cyan { color: #56d4dd; } .c-blue { color: #6ea8fe; }
.c-green { color: #4ade80; } .c-dim { color: #6b7488; }
.blink { animation: blink 1s steps(1) infinite; color: #ff9d5c; }
@keyframes blink { 50% { opacity: 0; } }

.pipe {
  display: flex; flex-wrap: wrap; align-items: center; gap: 8px;
  background: var(--surface); border: 1px solid var(--border); border-radius: 12px;
  padding: 12px 18px; font-family: var(--font-mono); font-size: .74rem; letter-spacing: .1em;
  color: var(--text-muted); box-shadow: var(--shadow-sm); justify-content: center;
}
.pipe i { color: var(--border-strong); font-style: normal; }
.pipe__ship { color: var(--accent); font-weight: 700; }
.pipe--wide { max-width: 660px; margin: 0 auto 52px; font-size: .78rem; }

/* ============================================================
   ICONS
   ============================================================ */
.ico {
  display: inline-grid; place-items: center; width: 40px; height: 40px; flex-shrink: 0;
  border-radius: 10px; background: var(--accent-tint); border: 1px solid var(--accent-border);
  color: var(--accent); margin-bottom: 16px;
}
.ico svg { width: 20px; height: 20px; display: block; }

/* ============================================================
   CARDS
   ============================================================ */
.cards { display: grid; gap: 20px; margin-top: 36px; }
.cards--3 { grid-template-columns: repeat(3, 1fr); }
.cards--4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 24px; transition: transform .2s ease, border-color .2s ease, box-shadow .2s ease;
}
.card:hover { transform: translateY(-3px); border-color: var(--border-strong); box-shadow: var(--shadow); }
.card h3 { margin-bottom: 8px; }
.card p { margin: 0; color: var(--text-muted); font-size: .95rem; }
.card--tall { min-height: 200px; }
.card__num {
  display: inline-grid; place-items: center; width: 34px; height: 34px; border-radius: 9px;
  font-family: var(--font-mono); font-weight: 700; color: var(--accent);
  background: var(--accent-tint); border: 1px solid var(--accent-border); margin-bottom: 14px;
}

/* ---------- Quote / callouts ---------- */
.quote {
  margin: 22px 0; padding: 18px 22px; border-left: 3px solid var(--accent);
  background: var(--accent-tint); border-radius: 0 10px 10px 0;
  font-family: var(--font-mono); font-size: .92rem; color: var(--text); max-width: 720px;
}
.callout {
  margin: 36px 0 0; padding: 22px 26px; border-radius: var(--radius);
  background: var(--surface); border: 1px solid var(--border); font-size: 1.03rem; max-width: 840px;
  color: var(--text-body);
}
.callout--soft { background: var(--accent-tint); border-color: var(--accent-border); }
.callout--big {
  font-family: var(--font-display); font-weight: 600; font-size: clamp(1.15rem, 2.2vw, 1.6rem);
  line-height: 1.4; background: none; border: 0; padding: 0; letter-spacing: -0.01em; color: var(--text);
}

/* ---------- Split ---------- */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; margin-top: 18px; }
.ticklist { list-style: none; padding: 0; margin: 14px 0; display: grid; gap: 9px; }
.ticklist li { position: relative; padding-left: 28px; color: var(--text-body); }
.ticklist li::before {
  content: ""; position: absolute; left: 2px; top: 9px; width: 12px; height: 7px;
  border-left: 2px solid var(--accent); border-bottom: 2px solid var(--accent);
  transform: rotate(-45deg);
}

/* ============================================================
   COMPARE
   ============================================================ */
.compare { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin: 36px 0; }
.compare__col {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px;
}
.compare__col--hl { border-color: var(--accent-border); background: var(--accent-tint); }
.compare__title { font-size: .82rem; margin-bottom: 15px; color: var(--text-muted); text-transform: uppercase; letter-spacing: .08em; font-family: var(--font-mono); font-weight: 500; }
.compare__col--hl .compare__title { color: var(--accent); }
.compare ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 11px; }
.compare li { padding-left: 22px; position: relative; color: var(--text-body); }
.compare li::before { content: "→"; position: absolute; left: 0; color: var(--text-muted); }
.compare__col--hl li::before { color: var(--accent); }

/* ---------- Before / After ---------- */
.beforeafter { margin-top: 60px; }
.beforeafter__grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin: 18px 0; }
.ba-card { border-radius: var(--radius); padding: 26px; border: 1px solid var(--border); background: var(--surface); }
.ba-card--after { border-color: var(--accent-border); background: var(--accent-tint); }
.ba-card__tag {
  font-family: var(--font-mono); font-size: .68rem; letter-spacing: .16em; text-transform: uppercase;
  color: var(--text-muted); display: block; margin-bottom: 13px;
}
.ba-card--after .ba-card__tag { color: var(--accent); }
.ba-card__quote { font-family: var(--font-display); font-size: 1.12rem; line-height: 1.42; margin: 0; color: var(--text); }
.beforeafter__note { text-align: center; color: var(--text-muted); max-width: 620px; margin: 14px auto 0; font-size: .94rem; }

/* ============================================================
   TIMELINE
   ============================================================ */
.timeline { list-style: none; padding: 0; margin: 0; display: grid; gap: 2px; position: relative; }
.timeline::before {
  content: ""; position: absolute; left: 27px; top: 14px; bottom: 14px; width: 2px;
  background: var(--border-strong);
}
.timeline__item { display: flex; gap: 22px; align-items: flex-start; padding: 16px 0; position: relative; }
.timeline__num {
  flex-shrink: 0; width: 56px; height: 56px; border-radius: 14px; display: grid; place-items: center;
  font-family: var(--font-mono); font-weight: 700; font-size: .95rem; color: var(--text-muted);
  background: var(--surface); border: 1px solid var(--border-strong); position: relative; z-index: 1;
  transition: color .25s ease, background .25s ease, border-color .25s ease;
}
.timeline__item.is-active .timeline__num { color: #fff; background: var(--accent); border-color: var(--accent); }
.timeline__item h3 { margin-bottom: 3px; }
.timeline__item p { margin: 0; color: var(--text-muted); }

/* ============================================================
   LEVELS
   ============================================================ */
.levels { display: grid; grid-template-columns: repeat(auto-fit, minmax(206px, 1fr)); gap: 18px; }
.level { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 22px; }
.level--current { border-color: var(--amber-border); background: var(--amber-tint); }
.level__head { margin-bottom: 14px; }
.level__badge {
  font-family: var(--font-mono); font-size: .66rem; letter-spacing: .12em; text-transform: uppercase;
  color: var(--text-muted); display: block; margin-bottom: 5px; font-weight: 500;
}
.level--current .level__badge { color: var(--amber); }
.level__head h3 { font-size: 1.02rem; }
.level__here {
  display: inline-block; margin-top: 8px; font-family: var(--font-mono); font-size: .66rem;
  letter-spacing: .08em; text-transform: uppercase; color: var(--amber);
  background: #fff; border: 1px solid var(--amber-border); padding: 3px 8px; border-radius: 6px;
}
.level ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 7px; }
.level li { font-size: .87rem; color: var(--text-muted); padding-left: 15px; position: relative; }
.level li::before { content: ""; position: absolute; left: 2px; top: 9px; width: 4px; height: 4px; border-radius: 50%; background: var(--border-strong); }

/* ============================================================
   WARNING
   ============================================================ */
.warning {
  background: var(--amber-tint); border: 1px solid var(--amber-border);
  border-radius: var(--radius-lg); padding: clamp(26px, 4vw, 48px);
}
.warning__head { display: flex; gap: 18px; align-items: flex-start; margin-bottom: 18px; }
.warning__mark {
  flex-shrink: 0; width: 42px; height: 42px; border-radius: 11px; display: grid; place-items: center;
  font-family: var(--font-display); font-weight: 700; font-size: 1.3rem; color: var(--amber);
  background: #fff; border: 1px solid var(--amber-border);
}
.qlist {
  list-style: none; padding: 0; margin: 20px 0; display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px;
}
.qlist li {
  font-family: var(--font-mono); font-size: .86rem; color: var(--text); padding: 11px 15px;
  background: #fff; border: 1px solid var(--amber-border); border-radius: 9px;
}
.qlist li::before { content: "› "; color: var(--amber); }

/* ============================================================
   CTA BAND
   ============================================================ */
.cta-band {
  margin-top: 44px; padding: clamp(30px, 4vw, 52px); border-radius: var(--radius-lg); text-align: center;
  background: var(--accent-tint); border: 1px solid var(--accent-border);
}
.cta-band h3 { font-size: clamp(1.35rem, 2.6vw, 1.9rem); margin-bottom: 10px; }
.cta-band p { color: var(--text-body); max-width: 500px; margin: 0 auto 22px; }

/* ============================================================
   ABOUT
   ============================================================ */
.about { display: grid; grid-template-columns: minmax(0, 400px) 1fr; gap: 44px; align-items: start; }
.about__portrait {
  width: 100%; aspect-ratio: 16 / 9; border-radius: var(--radius-lg); overflow: hidden;
  border: 1px solid var(--border); box-shadow: var(--shadow-sm);
}
.about__portrait img { width: 100%; height: 100%; object-fit: cover; }
.about__body p { color: var(--text-body); max-width: 62ch; }
.about__body h2 { margin-bottom: 16px; }
.cred { list-style: none; padding: 0; margin: 40px 0 0; display: flex; flex-wrap: wrap; gap: 10px; }
.cred li {
  font-family: var(--font-mono); font-size: .76rem; letter-spacing: .02em; color: var(--text-body);
  background: var(--surface); border: 1px solid var(--border-strong); border-radius: 999px; padding: 7px 15px;
}

/* ============================================================
   CONTACT CTA
   ============================================================ */
.contact-cta { max-width: 640px; }
.contact-cta .btn { margin: 6px 0 14px; }
.contact-cta__addr { font-size: .92rem; color: var(--text-muted); margin: 0; }

/* ============================================================
   FAQ
   ============================================================ */
.faq { display: grid; gap: 10px; max-width: 800px; }
.faq__item {
  background: var(--surface); border: 1px solid var(--border); border-radius: 12px;
  padding: 2px 20px; transition: border-color .18s ease, box-shadow .18s ease;
}
.faq__item[open] { border-color: var(--border-strong); box-shadow: var(--shadow-sm); }
.faq__item summary {
  cursor: pointer; list-style: none; padding: 17px 0; font-family: var(--font-display);
  font-weight: 600; font-size: 1rem; color: var(--text); display: flex; justify-content: space-between; gap: 16px; align-items: center;
}
.faq__item summary::-webkit-details-marker { display: none; }
.faq__item summary::after {
  content: "+"; font-family: var(--font-mono); font-size: 1.25rem; color: var(--accent);
  transition: transform .22s ease; flex-shrink: 0; line-height: 1;
}
.faq__item[open] summary::after { transform: rotate(45deg); }
.faq__item p { color: var(--text-body); margin: 0 0 17px; font-size: .95rem; }

/* ============================================================
   FINAL CTA
   ============================================================ */
.final { text-align: center; background: var(--bg-alt); border-top: 1px solid var(--border); }
.final__inner { max-width: 720px; margin-inline: auto; }
.final__inner h2 { margin-bottom: 18px; }
.final__inner p { color: var(--text-body); }
.final__inner .btn { margin-top: 22px; }
.final__sub { margin-top: 20px; font-size: .89rem; color: var(--text-muted); }

/* ============================================================
   FOOTER
   ============================================================ */
.footer { background: var(--bg); border-top: 1px solid var(--border); padding: 52px 0 30px; }
.footer__grid { display: flex; flex-wrap: wrap; gap: 32px; justify-content: space-between; align-items: start; }
.footer__name { font-family: var(--font-display); font-weight: 700; font-size: 1.15rem; margin: 0 0 4px; color: var(--text); }
.footer__role { color: var(--text-muted); font-size: .85rem; margin: 0; }
.footer__links, .footer__social { display: flex; flex-direction: column; gap: 9px; }
.footer__links a, .footer__social a { color: var(--text-muted); font-size: .89rem; }
.footer__links a:hover, .footer__social a:hover { color: var(--text); }
.footer__legal {
  display: flex; flex-wrap: wrap; gap: 16px; justify-content: space-between;
  margin-top: 38px; padding-top: 22px; border-top: 1px solid var(--border);
  color: var(--text-muted); font-size: .81rem;
}
.footer__legal nav { display: flex; gap: 18px; }
.footer__legal a { color: var(--text-muted); }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 980px) {
  .hero__grid { grid-template-columns: 1fr; gap: 44px; }
  .hero__lede { max-width: none; }
  .split { grid-template-columns: 1fr; gap: 26px; }
  .cards--4 { grid-template-columns: repeat(2, 1fr); }
  .about { grid-template-columns: 1fr; gap: 26px; }
  .about__portrait { max-width: 460px; }
}

@media (max-width: 760px) {
  .nav__links {
    position: fixed; inset: 64px 0 auto 0; flex-direction: column; gap: 0; margin: 0;
    background: #fff; border-bottom: 1px solid var(--border);
    padding: 12px 24px 22px; transform: translateY(-120%); transition: transform .28s ease;
    box-shadow: 0 12px 24px -12px rgba(15,23,41,.12);
  }
  .nav__links.is-open { transform: none; }
  .nav__links a { padding: 13px 0; border-bottom: 1px solid var(--border); font-size: .95rem; }
  .nav__toggle { display: flex; }
  .nav__cta { display: none; }

  .cards--3, .cards--4, .compare, .beforeafter__grid, .qlist { grid-template-columns: 1fr; }
  .footer__legal { flex-direction: column; gap: 12px; }
}