/* =========================================================
   Machine Learning: How Did We Get Here? — Signup Page
   Color palette derived from podcast cover art
   ========================================================= */

/* === Reset & Base === */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg:          #1a0e08;
  --surface:     #2b1408;
  --accent:      #c45a2a;
  --gold:        #e8b84b;
  --text:        #f0ede8;
  --text-muted:  #9b8c7e;
  --stanford-red: #8c1515;
  --cmu-red:     #c41230;
  --radius:      12px;
  --max-width:   640px;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

body {
  background-color: var(--bg);
  color: var(--text);
  font-family: 'Inter', system-ui, sans-serif;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* === Hero === */
.hero {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 48px 24px 56px;
  max-width: var(--max-width);
  margin: 0 auto;
  width: 100%;
}

/* Neural net decorative SVG */
.neural-bg {
  width: 100%;
  max-width: 420px;
  margin-bottom: 8px;
  opacity: 0.18;
}

.neural-bg svg {
  width: 100%;
  height: auto;
}

.node {
  fill: var(--gold);
}

.edge {
  stroke: var(--accent);
  stroke-width: 1;
}

/* Cover art */
.cover-wrap {
  margin-bottom: 32px;
}

.cover-art {
  width: 340px;
  height: 340px;
  object-fit: cover;
  border-radius: 16px;
  box-shadow:
    0 8px 32px rgba(0, 0, 0, 0.6),
    0 0 0 2px rgba(232, 184, 75, 0.2);
}

/* Headline */
.headline {
  font-family: 'Playfair Display', Georgia, serif;
  font-size: clamp(1.8rem, 5vw, 2.6rem);
  font-weight: 900;
  line-height: 1.15;
  color: var(--gold);
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

/* Host line */
.host-line {
  font-size: 1rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  letter-spacing: 0.02em;
}

.host-line strong {
  color: var(--text);
  font-weight: 600;
}

/* Description */
.description {
  font-size: 1.05rem;
  color: var(--text);
  max-width: 520px;
  margin-bottom: 44px;
  line-height: 1.75;
  opacity: 0.9;
}

/* Host link */
.host-link {
  color: inherit;
  text-decoration: underline;
  text-decoration-color: rgba(240, 237, 232, 0.35);
  text-underline-offset: 3px;
  transition: text-decoration-color 0.2s;
}

.host-link:hover {
  text-decoration-color: var(--text);
}

/* === Episodes Block === */
.episodes-block {
  width: 100%;
  max-width: 480px;
  margin-bottom: 28px;
}

.episodes-label {
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 10px;
}

.episodes-list {
  list-style: none;
  padding: 0;
  margin: 0;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.episodes-list li {
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.episodes-list li a {
  display: block;
  padding: 9px 4px;
  color: var(--text);
  text-decoration: none;
  font-size: 0.9rem;
  line-height: 1.4;
  transition: color 0.15s, padding-left 0.15s;
}

.episodes-list li a:hover {
  color: var(--gold);
  padding-left: 8px;
}

.episodes-audio {
  margin-top: 12px;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-muted);
  text-align: center;
}

.episodes-audio a {
  color: var(--gold);
  text-decoration: none;
  opacity: 0.85;
}

.episodes-audio a:hover {
  opacity: 1;
  text-decoration: underline;
}

/* === Signup Block === */
.signup-block {
  width: 100%;
  max-width: 480px;
  background: var(--surface);
  border: 1px solid rgba(232, 184, 75, 0.15);
  border-radius: var(--radius);
  padding: 32px 28px;
}

.signup-label {
  font-family: 'Playfair Display', Georgia, serif;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--gold);
  margin-bottom: 16px;
}

.signup-form {
  display: flex;
  gap: 10px;
}

.email-input {
  flex: 1;
  background: var(--bg);
  border: 1px solid rgba(232, 184, 75, 0.3);
  border-radius: 50px;
  color: var(--text);
  font-family: 'Inter', sans-serif;
  font-size: 0.95rem;
  padding: 12px 20px;
  outline: none;
  transition: border-color 0.2s;
}

.email-input::placeholder {
  color: var(--text-muted);
}

.email-input:focus {
  border-color: var(--gold);
}

.cta-btn {
  background: var(--gold);
  border: none;
  border-radius: 50px;
  color: #1a0e08;
  cursor: pointer;
  font-family: 'Inter', sans-serif;
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  padding: 12px 24px;
  white-space: nowrap;
  transition: background 0.2s, transform 0.1s;
}

.cta-btn:hover {
  background: #f5ca5c;
}

.cta-btn:active {
  transform: scale(0.97);
}

.signup-note {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 12px;
  text-align: center;
}

.signup-msg {
  min-height: 1.2em;
  font-size: 0.85rem;
  font-weight: 600;
  margin-top: 10px;
  text-align: center;
}

.signup-msg--ok  { color: #6fcf97; }
.signup-msg--err { color: #eb5757; }

/* === Sponsors === */
.sponsors {
  background: var(--surface);
  border-top: 1px solid rgba(232, 184, 75, 0.1);
  padding: 40px 24px;
  text-align: center;
}

.sponsors-label {
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 20px;
  font-weight: 600;
}

.sponsors-grid {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  max-width: var(--max-width);
  margin: 0 auto;
}

.sponsor-card {
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius);
  padding: 16px 28px;
  text-decoration: none;
  min-width: 200px;
  flex: 1;
  max-width: 280px;
  transition: opacity 0.2s, transform 0.15s;
}

.sponsor-card:hover {
  opacity: 0.88;
  transform: translateY(-2px);
}

.sponsor-stanford {
  background-color: var(--stanford-red);
}

.sponsor-cmu {
  background-color: var(--cmu-red);
}

.sponsor-name {
  color: #fff;
  font-family: 'Inter', sans-serif;
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-align: center;
  line-height: 1.3;
}

/* === Footer === */
.footer {
  background: #120a05;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding: 20px 24px;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.footer p {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.footer a {
  color: var(--gold);
  text-decoration: none;
  opacity: 0.8;
}

.footer a:hover {
  opacity: 1;
  text-decoration: underline;
}

/* === Responsive === */
@media (max-width: 520px) {
  .cover-art {
    width: 242px;
    height: 242px;
  }

  .signup-form {
    flex-direction: column;
  }

  .cta-btn {
    width: 100%;
    padding: 14px;
    font-size: 1rem;
  }

  .email-input {
    width: 100%;
  }

  .sponsor-card {
    min-width: 160px;
  }
}