/* -----------------------------------------------------------
   The Complete Shortwave Listener — design tokens
   Palette drawn from an SDR waterfall display (teal / amber /
   magenta traces on near-black), which is genuinely one of the
   book's chapters — not a generic dark theme.
----------------------------------------------------------- */
:root{
  --ink: #0B0F14;
  --panel: #121820;
  --panel-2: #17202B;
  --paper: #E8ECEF;
  --muted: #8695A3;
  --line: #263241;

  --signal-teal: #2DD4BF;
  --signal-amber: #F5A623;
  --signal-magenta: #D6409F;

  --font-display: 'Space Mono', 'IBM Plex Mono', monospace;
  --font-body: 'IBM Plex Sans', system-ui, sans-serif;
  --font-mono: 'IBM Plex Mono', monospace;

  --radius: 3px;
  --wrap: 1120px;
}

*, *::before, *::after{ box-sizing: border-box; }
html{ scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce){
  html{ scroll-behavior: auto; }
  *{ animation: none !important; transition: none !important; }
}

body{
  margin: 0;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

h1, h2, h3{
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.15;
  margin: 0 0 .5em;
  letter-spacing: -0.01em;
}
h2{ font-size: clamp(1.6rem, 3vw, 2.2rem); }
h3{ font-size: 1.15rem; }
p{ margin: 0 0 1em; color: var(--muted); }
em{ color: var(--paper); font-style: normal; border-bottom: 1px solid var(--signal-teal); }

a{ color: var(--signal-teal); }

.skip-link{
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--signal-amber);
  color: var(--ink);
  padding: 10px 16px;
  z-index: 100;
  font-family: var(--font-mono);
}
.skip-link:focus{ left: 12px; top: 12px; }

:focus-visible{
  outline: 2px solid var(--signal-amber);
  outline-offset: 2px;
}

/* ---------------- header ---------------- */
.site-header{
  border-bottom: 1px solid var(--line);
  padding: 18px 0;
}
.header-row{
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
.brand{
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--paper);
  text-decoration: none;
  letter-spacing: 0.02em;
}
.brand-mark{ color: var(--signal-amber); margin-right: 8px; }

/* ---------------- hero ---------------- */
.hero{
  position: relative;
  overflow: hidden;
  padding: 90px 0 0;
  border-bottom: 1px solid var(--line);
}
.waterfall{
  position: absolute;
  inset: 0;
  z-index: 0;
  opacity: 0.55;
}
.waterfall svg{ width: 100%; height: 100%; }
.traces path{
  fill: none;
  stroke-width: 2.5;
  opacity: 0.55;
}

.hero-inner{
  position: relative;
  z-index: 1;
  padding-bottom: 70px;
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 48px;
  align-items: center;
}
.hero-cover{ display: flex; justify-content: center; }
.hero-cover img{
  width: 100%;
  max-width: 320px;
  height: auto;
  border-radius: var(--radius);
  box-shadow: 0 20px 60px rgba(0,0,0,0.5);
}
.cover-placeholder{
  width: 100%;
  max-width: 300px;
  aspect-ratio: 2 / 3;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    linear-gradient(160deg, var(--panel-2) 0%, var(--panel) 100%);
  box-shadow: 0 20px 60px rgba(0,0,0,0.5);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: 18px;
  padding: 24px;
  position: relative;
}
.cover-placeholder::before{
  content: "";
  position: absolute;
  inset: 14px;
  border: 1px solid var(--signal-amber);
  opacity: 0.4;
  border-radius: 2px;
}
.cover-placeholder-title{
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.3rem;
  line-height: 1.3;
  color: var(--paper);
}
.cover-placeholder-author{
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--signal-amber);
}
.eyebrow{
  font-family: var(--font-mono);
  color: var(--signal-amber);
  font-size: 0.85rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 14px;
}
.hero h1{
  font-size: clamp(2.2rem, 6vw, 3.6rem);
  color: var(--paper);
  max-width: 14ch;
}
.hero-lede{
  max-width: 56ch;
  font-size: 1.05rem;
  color: #B7C2CC;
}
.cta-row{
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 28px;
}

.btn{
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  text-decoration: none;
  padding: 13px 22px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform .12s ease, background .12s ease, border-color .12s ease;
}
.btn-primary{
  background: var(--signal-teal);
  color: #04211D;
  font-weight: 700;
}
.btn-primary:hover{ transform: translateY(-1px); background: #45E0CC; }
.btn-ghost{
  background: transparent;
  color: var(--paper);
  border-color: var(--line);
}
.btn-ghost:hover{ border-color: var(--signal-amber); color: var(--signal-amber); }
.btn:disabled{ opacity: 0.6; cursor: not-allowed; transform: none; }

.band-strip{
  position: relative;
  z-index: 1;
  display: flex;
  border-top: 1px solid var(--line);
  background: var(--panel);
  overflow-x: auto;
}
.band-strip span{
  flex: 1 0 auto;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--muted);
  text-align: center;
  padding: 10px 14px;
  border-right: 1px solid var(--line);
  white-space: nowrap;
}
.band-strip span:last-child{ border-right: none; }

/* ---------------- sections ---------------- */
.section{ padding: 84px 0; }
.section-alt{ background: var(--panel); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section-lede{ max-width: 60ch; font-size: 1.05rem; }

.part-grid{
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 40px;
}
.part-card{
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 3px solid var(--signal-teal);
  border-radius: var(--radius);
  padding: 26px 24px;
}
.part-card:nth-child(2){ border-top-color: var(--signal-amber); }
.part-card:nth-child(3){ border-top-color: var(--signal-magenta); }
.part-label{
  font-family: var(--font-mono);
  color: var(--muted);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 10px;
}
.part-card h3{ color: var(--paper); }
.part-card p{ margin-bottom: 0; font-size: 0.95rem; }

.author-grid{
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 40px;
  align-items: center;
}
.photo-placeholder{
  width: 200px;
  height: 200px;
  border-radius: 50%;
  border: 2px solid var(--signal-amber);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  color: var(--signal-amber);
  background: var(--panel-2);
}
.author-grid h2{ color: var(--paper); }
.author-grid p:last-child{ margin-bottom: 0; }

/* ---------------- register form ---------------- */
.register-wrap{ max-width: 560px; }
.register-form{ margin-top: 32px; }
.field{ margin-bottom: 18px; }
.field label{
  display: block;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--muted);
  margin-bottom: 6px;
}
.field input[type="text"],
.field input[type="email"]{
  width: 100%;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--paper);
  padding: 12px 14px;
  font-family: var(--font-body);
  font-size: 1rem;
}
.field input[type="text"]:focus,
.field input[type="email"]:focus{
  border-color: var(--signal-teal);
}
.field-check{
  display: flex;
  align-items: flex-start;
  gap: 10px;
}
.field-check label{
  font-family: var(--font-body);
  font-size: 0.9rem;
  color: var(--muted);
  margin-bottom: 0;
}
.field-check input{ margin-top: 4px; }

/* Honeypot — hidden from sighted users, still in tab/DOM order removed */
.hp-field{
  position: absolute;
  left: -9999px;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

.form-status{
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  min-height: 1.4em;
}
.form-status[data-state="ok"]{ color: var(--signal-teal); }
.form-status[data-state="error"]{ color: #F16565; }

/* ---------------- footer ---------------- */
.site-footer{
  border-top: 1px solid var(--line);
  padding: 28px 0;
}
.footer-row{
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 0.85rem;
}
.footer-row p{ margin: 0; color: var(--muted); }

/* ---------------- responsive ---------------- */
@media (max-width: 760px){
  .part-grid{ grid-template-columns: 1fr; }
  .author-grid{ grid-template-columns: 1fr; text-align: left; }
  .photo-placeholder{ width: 140px; height: 140px; }
  .hero{ padding-top: 60px; }
  .section{ padding: 56px 0; }
  .hero-inner{ grid-template-columns: 1fr; gap: 36px; }
  .hero-cover{ order: -1; }
  .cover-placeholder{ max-width: 220px; }
}