:root {
  --bg-primary: #0a1629;
  --bg-secondary: #0f1f38;
  --bg-card: #172a47;
  --text-primary: #e6f0fa;
  --text-secondary: #b8d1e8;
  --accent-cyan: #22d3ee;
  --accent-teal: #0ea5e9;
  --accent-blue: #0369a1;
  --border: #1e3a5f;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  line-height: 1.6;
}

a { color: var(--accent-cyan); text-decoration: none; }
a:hover { text-decoration: underline; }

.container { max-width: 1200px; margin: 0 auto; padding: 0 1.5rem; }

header {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  padding: 1.2rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.logo-wrap { display: flex; align-items: center; gap: 1rem; }
.logo-img { height: 72px; width: auto; display: block; }
.logo-text {
  font-size: 1.5rem; font-weight: 700;
  background: linear-gradient(135deg, #0c2544, #22d3ee);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

nav a {
  margin: 0 0.75rem;
  color: var(--text-secondary);
  font-weight: 500;
}
nav a:hover, nav a.active { color: var(--accent-cyan); }

section { padding: 3.5rem 0; }

h1 {
  font-size: 2.6rem;
  margin-bottom: 1.2rem;
  line-height: 1.2;
  text-align: center;
}
h1 small { font-size: 1.4rem; color: var(--accent-cyan); }
h2 { font-size: 1.8rem; margin: 0 0 1rem; color: var(--accent-cyan); }
h3 { font-size: 1.2rem; margin: 0 0 0.5rem; color: var(--text-primary); }
p { margin-bottom: 1rem; color: var(--text-secondary); font-size: 1.05rem; }

.hero {
  padding: 4rem 0;
  text-align: center;
  background: radial-gradient(circle at top, #172a47, transparent 70%);
}
.hero p { font-size: 1.15rem; max-width: 800px; margin: 0 auto; }

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.5rem;
}

/* ==============================================
   📖 BOOK PAGE — COVER + PREFACE + FULL-WIDTH FORM
   ============================================== */
.book-grid {
  display: grid !important;
  grid-template-columns: 300px 1fr !important;
  gap: 40px !important;
  align-items: start !important;
  width: 100% !important;
  max-width: 1200px !important;
  margin: 0 auto !important;
}

.book-grid > * {
  margin: 0 !important;
  padding: 0 !important;
  float: none !important;
  display: block !important;
}

.book-cover-col {
  width: 300px !important;
  flex: 0 0 300px !important;
  min-width: 300px !important;
  max-width: 300px !important;
  text-align: center;
}

.book-cover {
  width: 100%;
  max-width: 280px;
  height: auto;
  border-radius: 12px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
  display: block;
  margin: 0 auto;
}

.book-preface-col {
  width: 100% !important;
  flex: 1 !important;
}

/* FULL-WIDTH FORM */
.book-form-fullwidth {
  margin-top: 3rem;
}

.book-form-fullwidth h3 {
  margin-bottom: 1rem;
  color: var(--accent-cyan);
}

.fullwidth-form {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 2rem;
  max-width: 100%;
  margin: 0;
}

.fullwidth-form .form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.fullwidth-form label {
  margin: 0.8rem 0 0.3rem;
  font-size: 0.95rem;
}

.fullwidth-form input,
.fullwidth-form textarea {
  width: 100%;
  padding: 0.85rem 1rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 1rem;
}

.fullwidth-form input:focus,
.fullwidth-form textarea:focus {
  outline: none;
  border-color: var(--accent-cyan);
  box-shadow: 0 0 0 3px rgba(34, 211, 238, 0.15);
}

.fullwidth-form textarea { resize: none; }

.fullwidth-form button {
  margin-top: 1.5rem;
  padding: 0.9rem 2rem;
  background: linear-gradient(135deg, #0369a1, #0ea5e9);
  color: white;
  border: none;
  border-radius: 6px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: opacity 0.2s;
  width: auto;
}
.fullwidth-form button:hover { opacity: 0.9; }

/* STANDARD CONTACT FORM (Homepage) */
form {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 2rem;
  max-width: 600px;
  margin: 2rem auto;
}

form label { display: block; margin: 1rem 0 0.4rem; font-weight: 500; }
form input, form textarea {
  width: 100%;
  padding: 0.85rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 1rem;
}
form input:focus, form textarea:focus {
  outline: none;
  border-color: var(--accent-cyan);
  box-shadow: 0 0 0 3px rgba(34, 211, 238, 0.15);
}

form button {
  margin-top: 1.5rem;
  padding: 0.9rem 2rem;
  background: linear-gradient(135deg, #0369a1, #0ea5e9);
  color: white;
  border: none;
  border-radius: 6px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: opacity 0.2s;
  width: 100%;
}
form button:hover { opacity: 0.9; }

/* AJAX FORM STATUS MESSAGES */
.form-status {
  margin-top: 0.85rem;
  padding: 0.75rem;
  border-radius: 6px;
  font-size: 0.9rem;
  line-height: 1.4;
  display: none;
}
.form-status.success {
  display: block;
  background: rgba(34, 197, 94, 0.1);
  border: 1px solid rgba(34, 197, 94, 0.3);
  color: #86efac;
}
.form-status.error {
  display: block;
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.3);
  color: #fca5a5;
}
button:disabled { opacity: 0.6; cursor: not-allowed; }

.note { font-size: 0.9rem; color: #8fb8d8; margin-top: 1rem; }
code { background: #0f2847; padding: 2px 6px; border-radius: 4px; }

footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  margin-top: 1rem;
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* ==============================================
   📱 RESPONSIVE — Stack on Mobile
   ============================================== */
@media (max-width: 900px) {
  .book-grid {
    grid-template-columns: 1fr !important;
    gap: 2rem !important;
  }
  .book-cover-col {
    width: 100% !important;
    max-width: 100% !important;
    flex: none !important;
  }
  .book-cover { width: 260px; }
  .fullwidth-form .form-row { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
  h1 { font-size: 1.9rem; }
  .nav-inner { flex-direction: column; text-align: center; }
  nav { margin-top: 0.5rem; }
  nav a { display: inline-block; padding: 0.4rem; margin: 0.1rem; }
  form { padding: 1.5rem; margin: 2rem 1rem; }
}
/* Clickable Logo - Hover Effect */
a:has(.logo-wrap) { transition: opacity 0.2s ease; }
a:has(.logo-wrap):hover { opacity: 0.85; text-decoration: none; }