/* ============================================================
   Zero to SQL — site styles (Kovoco branding)
   ============================================================ */
:root{
  --navy:#0D2B4E;
  --blue:#146BCD;
  --orange:#E85D24;
  --teal:#2AA876;
  --sky:#F4F6FA;
  --ink:#12283F;
  --muted:#5B6B7E;
  --line:#E1E7EF;
  --white:#ffffff;
  --radius:14px;
  --shadow:0 10px 30px rgba(13,43,78,.10);
  --shadow-lg:0 24px 60px rgba(13,43,78,.18);
  --maxw:1120px;
  --head:"Inter",system-ui,-apple-system,Segoe UI,Roboto,sans-serif;
  --body:"Nunito Sans",system-ui,-apple-system,Segoe UI,Roboto,sans-serif;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;font-family:var(--body);color:var(--ink);background:var(--white);
  line-height:1.65;font-size:18px;-webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4{font-family:var(--head);color:var(--navy);line-height:1.15;margin:0 0 .5em}
h1{font-size:clamp(2.1rem,5vw,3.4rem);font-weight:800;letter-spacing:-.02em}
h2{font-size:clamp(1.6rem,3.5vw,2.3rem);font-weight:800;letter-spacing:-.01em}
h3{font-size:1.25rem;font-weight:700}
p{margin:0 0 1rem}
a{color:var(--blue);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%;display:block}
.container{max-width:var(--maxw);margin:0 auto;padding:0 24px}
.eyebrow{font-family:var(--head);font-weight:700;text-transform:uppercase;letter-spacing:.12em;
  font-size:.8rem;color:var(--teal);margin:0 0 .6rem}
.muted{color:var(--muted)}
.center{text-align:center}

/* ---- buttons ---- */
.btn{display:inline-flex;align-items:center;gap:.55rem;font-family:var(--head);font-weight:700;
  font-size:1rem;padding:.85rem 1.5rem;border-radius:999px;border:2px solid transparent;
  cursor:pointer;transition:transform .12s ease,box-shadow .12s ease,background .12s ease;text-decoration:none}
.btn:hover{text-decoration:none;transform:translateY(-2px)}
.btn-primary{background:var(--orange);color:#fff;box-shadow:0 8px 20px rgba(232,93,36,.28)}
.btn-primary:hover{background:#d9521c;color:#fff}
.btn-secondary{background:transparent;color:var(--navy);border-color:var(--navy)}
.btn-secondary:hover{background:var(--navy);color:#fff}
.btn-ghost{background:#fff;color:var(--navy);border-color:var(--line);box-shadow:var(--shadow)}
.btn-ghost:hover{border-color:var(--blue);color:var(--blue)}
.btn-sm{padding:.55rem 1rem;font-size:.9rem}

/* ---- nav ---- */
.nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.9);
  backdrop-filter:saturate(160%) blur(8px);border-bottom:1px solid var(--line)}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:66px}
.brand{display:flex;align-items:center;gap:.6rem;font-family:var(--head);font-weight:800;
  color:var(--navy);font-size:1.15rem;letter-spacing:-.01em}
.brand:hover{text-decoration:none}
.brand .mark{width:30px;height:30px;flex:none}
.nav-links{display:flex;align-items:center;gap:1.6rem}
.nav-links a{font-family:var(--head);font-weight:600;color:var(--navy);font-size:.98rem}
.nav-links a:hover{color:var(--blue);text-decoration:none}

/* ---- badge ---- */
.badge{display:inline-flex;align-items:center;gap:.5rem;background:var(--navy);color:#fff;
  border-radius:999px;padding:.4rem .9rem .4rem .7rem;font-family:var(--head);font-weight:700;
  font-size:.82rem;line-height:1.2}
.badge .tick{color:#fff;background:var(--orange);border-radius:50%;width:20px;height:20px;
  display:inline-flex;align-items:center;justify-content:center;font-size:.75rem;flex:none}
.badge b{font-weight:800}
.badge.status{background:var(--teal)}

/* ---- hero ---- */
.hero{background:linear-gradient(180deg,#fff 0%,var(--sky) 100%);padding:64px 0 72px;overflow:hidden}
.hero-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:56px;align-items:center}
.hero h1{margin-bottom:.35em}
.hero .lead{font-size:1.2rem;color:var(--muted);max-width:34ch;margin-bottom:1.6rem}
.hero-cta{display:flex;flex-wrap:wrap;gap:.8rem;margin-bottom:1.4rem}
.hero-meta{display:flex;align-items:center;gap:1rem;flex-wrap:wrap;color:var(--muted);font-size:.95rem}
.cover-wrap{justify-self:center;position:relative}
.cover{width:min(360px,80vw);border-radius:12px;box-shadow:var(--shadow-lg);
  border:1px solid rgba(13,43,78,.08);transform:rotate(1.5deg);transition:transform .3s ease}
.cover-wrap:hover .cover{transform:rotate(0deg) translateY(-4px)}
.cover-tag{position:absolute;left:-14px;bottom:26px;background:var(--orange);color:#fff;
  font-family:var(--head);font-weight:800;font-size:.85rem;padding:.5rem .9rem;border-radius:10px;
  box-shadow:var(--shadow);transform:rotate(-3deg)}

/* ---- sections ---- */
section{padding:60px 0}
.section-sky{background:var(--sky)}
.section-navy{background:var(--navy);color:#dbe6f4}
.section-navy h2,.section-navy h3{color:#fff}
.section-navy .eyebrow{color:#7fd8b6}
.narrow{max-width:760px}

/* ---- learn list ---- */
.learn{display:grid;grid-template-columns:1fr 1fr;gap:.9rem 2rem;margin:1.5rem 0 0;padding:0;list-style:none}
.learn li{display:flex;gap:.7rem;align-items:flex-start;font-size:1.03rem}
.learn li::before{content:"";flex:none;width:22px;height:22px;margin-top:2px;border-radius:6px;
  background:var(--teal) url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'><path d='M20 6 9 17l-5-5'/></svg>") center/14px no-repeat}

/* ---- value strip ---- */
.value{background:#fff;border:1px solid var(--line);border-left:5px solid var(--orange);
  border-radius:var(--radius);padding:1.4rem 1.6rem;box-shadow:var(--shadow);font-size:1.12rem}
.value b{color:var(--navy)}

/* ---- cards ---- */
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;margin-top:2rem}
.card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:1.5rem;
  box-shadow:var(--shadow);display:flex;flex-direction:column}
.card h3{display:flex;align-items:center;gap:.55rem;margin-bottom:.2rem}
.card .db-dot{width:12px;height:12px;border-radius:50%;flex:none}
.card .sub{color:var(--muted);font-size:.92rem;margin-bottom:1rem}
.card .dl{display:flex;flex-direction:column;gap:.55rem;margin-top:auto}
.card .dl a{display:flex;align-items:center;justify-content:space-between;gap:.5rem;
  border:1px solid var(--line);border-radius:10px;padding:.6rem .85rem;color:var(--navy);
  font-family:var(--head);font-weight:600;font-size:.92rem}
.card .dl a:hover{border-color:var(--blue);color:var(--blue);text-decoration:none;background:var(--sky)}
.card .dl .ext{color:var(--muted);font-size:.78rem;font-weight:700}

/* ---- steps ---- */
.steps{counter-reset:step;list-style:none;padding:0;margin:1.5rem 0 0;display:grid;gap:1rem}
.steps li{position:relative;padding-left:3rem}
.steps li::before{counter-increment:step;content:counter(step);position:absolute;left:0;top:-2px;
  width:2rem;height:2rem;background:var(--blue);color:#fff;border-radius:50%;font-family:var(--head);
  font-weight:800;display:flex;align-items:center;justify-content:center}
code{background:#eef2f8;border:1px solid var(--line);border-radius:6px;padding:.1rem .4rem;
  font-family:ui-monospace,SFMono-Regular,Consolas,monospace;font-size:.9em;color:var(--navy)}

/* ---- callout ---- */
.callout{background:linear-gradient(120deg,var(--blue),var(--navy));color:#fff;border-radius:20px;
  padding:44px;display:flex;align-items:center;justify-content:space-between;gap:28px;flex-wrap:wrap;
  box-shadow:var(--shadow-lg)}
.callout h2{color:#fff;margin-bottom:.3em}
.callout p{color:#cfe0f5;margin:0;max-width:52ch}

/* ---- what's inside table ---- */
.facts{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:14px;margin-top:1.5rem}
.fact{background:#fff;border:1px solid var(--line);border-radius:12px;padding:1rem 1.2rem;box-shadow:var(--shadow)}
.fact .n{font-family:var(--head);font-weight:800;font-size:1.5rem;color:var(--blue)}
.fact .l{color:var(--muted);font-size:.9rem}

/* ---- footer ---- */
.footer{background:var(--navy);color:#a9bdd6;padding:44px 0;font-size:.95rem}
.footer a{color:#cfe0f5}
.footer-inner{display:flex;justify-content:space-between;gap:24px;flex-wrap:wrap;align-items:center}
.footer .brand{color:#fff}
.social{display:flex;gap:1.1rem}

/* ---- author (About page) ---- */
.author{display:grid;grid-template-columns:200px 1fr;gap:40px;align-items:start;margin-top:1.5rem}
.avatar{width:200px;height:200px;border-radius:18px;background:linear-gradient(135deg,var(--blue),var(--navy));
  color:#fff;font-family:var(--head);font-weight:800;font-size:4rem;display:flex;align-items:center;
  justify-content:center;box-shadow:var(--shadow-lg);object-fit:cover;object-position:50% 20%}
.author .lead{font-size:1.2rem;color:var(--muted);margin-bottom:1rem}
.signature{font-family:var(--head);font-weight:800;color:var(--navy);font-size:1.15rem;margin-top:1.4rem}

/* ---- home page bio strip ---- */
.bio{display:grid;grid-template-columns:132px 1fr;gap:32px;align-items:center;margin-top:1.4rem}
.bio-photo{width:132px;height:132px;border-radius:50%;object-fit:cover;object-position:50% 22%;
  box-shadow:var(--shadow-lg);border:4px solid #fff}
.bio h2{margin-bottom:.4rem}
.bio p{color:var(--muted);margin-bottom:.8rem}
.bio .bio-links a{font-family:var(--head);font-weight:700}

/* ---- lessons / table of contents ---- */
.toc-group{margin-top:2.2rem}
.toc-group h3{color:var(--navy);border-bottom:2px solid var(--line);padding-bottom:.5rem;margin-bottom:1rem}
.lessons{list-style:none;margin:0;padding:0;display:grid;gap:.7rem}
.lesson{display:flex;gap:1rem;align-items:flex-start;background:#fff;border:1px solid var(--line);
  border-radius:12px;padding:1rem 1.2rem;box-shadow:var(--shadow)}
.lesson .num{flex:none;width:2.4rem;height:2.4rem;border-radius:10px;background:var(--sky);color:var(--blue);
  font-family:var(--head);font-weight:800;font-size:1.05rem;display:flex;align-items:center;justify-content:center}
.lesson .body h4{margin:0 0 .15rem;font-size:1.08rem}
.lesson .body p{margin:0;color:var(--muted);font-size:.96rem}

/* ---- table (Errata) ---- */
.table{width:100%;border-collapse:collapse;margin-top:1.5rem;font-size:.98rem}
.table th,.table td{text-align:left;padding:.8rem 1rem;border-bottom:1px solid var(--line);vertical-align:top}
.table th{font-family:var(--head);color:var(--navy);font-size:.82rem;text-transform:uppercase;letter-spacing:.08em}
.table tr:hover td{background:var(--sky)}
.notice{background:var(--sky);border:1px dashed var(--line);border-radius:var(--radius);
  padding:1.6rem 1.8rem;color:var(--muted);text-align:center;margin-top:1.5rem}

/* ---- code blocks ---- */
.code-lang{font-family:var(--head);font-weight:700;font-size:.78rem;text-transform:uppercase;
  letter-spacing:.08em;color:var(--blue);margin:1.4rem 0 .4rem}
pre.code{background:var(--navy);color:#e8eef6;border-radius:12px;padding:1.1rem 1.3rem;margin:0 0 1rem;
  overflow-x:auto;box-shadow:var(--shadow);font-family:ui-monospace,SFMono-Regular,Consolas,monospace;
  font-size:.9rem;line-height:1.6}
pre.code code{background:none;border:none;padding:0;color:inherit;font-size:inherit}
.rdbms{margin-top:2.4rem;padding-top:.4rem}
.rdbms h2{display:flex;align-items:center;gap:.6rem}
.rdbms h2 .db-dot{width:14px;height:14px;border-radius:50%;flex:none}

/* ---- prose (Privacy) ---- */
.prose h3{margin-top:2rem}
.prose ul{padding-left:1.2rem}
.prose li{margin-bottom:.4rem}
.prose .updated{color:var(--muted);font-size:.95rem}

/* ---- responsive ---- */
@media(max-width:860px){
  .author{grid-template-columns:1fr;gap:20px}
  .avatar{width:140px;height:140px;font-size:2.8rem}
  .bio{grid-template-columns:1fr;gap:16px;justify-items:start}
  .hero-grid{grid-template-columns:1fr;gap:36px}
  .cover-wrap{order:-1}
  .learn{grid-template-columns:1fr}
  .cards{grid-template-columns:1fr}
  .nav-links{gap:1rem}
  .nav-links .hide-sm{display:none}
}
@media(max-width:520px){
  body{font-size:17px}
  .callout{padding:28px}
  section{padding:44px 0}
}