/* ================================
   BookWave UI — Light Theme
   Mobile-first, responsive, clean
   ================================ */

:root{
  /* Palette */
  --bg: #f7f8fb;
  --surface: #ffffff;
  --surface-2: #fafafa;
  --text: #0f172a;          /* slate-900 */
  --muted: #64748b;         /* slate-500 */
  --border: #e5e7eb;        /* gray-200 */
  --primary: #2563eb;       /* blue-600 */
  --primary-600: #1d4ed8;
  --primary-50: #eff6ff;    /* subtle bg */
  --success: #16a34a;
  --warning: #f59e0b;
  --danger: #dc2626;

  /* Elevation & radii */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 22px;
  --shadow-xs: 0 1px 2px rgba(15,23,42,.05);
  --shadow-sm: 0 2px 8px rgba(15,23,42,.06);
  --shadow-md: 0 10px 25px rgba(15,23,42,.08);
  --shadow-lg: 0 18px 45px rgba(15,23,42,.08);

  /* Layout */
  --container: 1100px;

  /* Typography */
  --font-sans: ui-sans-serif, system-ui, -apple-system, "SF Pro Text", Segoe UI, Roboto, Inter, "Helvetica Neue", Arial, sans-serif;
  --fs-sm: 0.875rem;
  --fs-base: 0.95rem;
  --fs-lg: 1.05rem;
  --fs-xl: 1.35rem;
  --fs-2xl: 1.75rem;
}

/* Reset-ish */
*,*::before,*::after{ box-sizing: border-box; }
html,body{ height: 100%; }
body{
  margin:0;
  font-family: var(--font-sans);
  color: var(--text);
  background: var(--bg);
  font-size: var(--fs-base);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
img{ max-width:100%; display:block; }
a{ color: var(--primary); text-decoration: none; }
a:hover{ text-decoration: underline; }

.container{
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 16px;
}

/* Layout shell */
.layout{
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ================= NAVBAR ================= */
.navbar{
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,0.9);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--border);
}
.navbar-inner{
  display:flex; align-items:center; justify-content:space-between;
  padding: 10px 0;
}
.nav-brand{
  display:flex; align-items:center; gap:10px;
  font-weight: 700; letter-spacing: .2px;
}
.logo-dot{
  width:12px; height:12px; border-radius:999px; background: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-50);
}
.nav-links{
  display:flex; gap: 16px; align-items:center;
}
.nav-links a{
  color: var(--muted);
  padding: 8px 10px; border-radius: 8px;
}
.nav-links a.active, .nav-links a:hover{
  color: var(--primary);
  background: var(--primary-50);
  text-decoration: none;
}
.nav-cta{
  display:inline-flex; align-items:center; gap:8px;
  background: var(--primary); color: #fff; border: 1px solid transparent;
  padding: 8px 14px; font-weight: 600; border-radius: 999px;
  box-shadow: var(--shadow-sm);
}
.nav-cta:hover{ background: var(--primary-600); text-decoration: none; }

/* Mobile nav toggler */
.nav-toggle{
  appearance: none; background: transparent; border: 1px solid var(--border);
  padding: 8px; border-radius: 10px; display:flex; gap:6px; align-items:center;
}
.nav-toggle span{ width:18px; height:2px; background:#334155; display:block; }
.nav-menu{ display:none; }
.nav-menu.open{ display:block; }

/* ================= MAIN ================= */
.main{ flex:1; padding: 18px 0 28px; }

/* ================= HERO ================= */
.hero{
  display:grid; gap: 20px; align-items: center;
}
.hero .title{
  font-size: var(--fs-2xl); font-weight:800; line-height:1.15;
}
.hero .title span{ color: var(--primary); }
.hero .subtitle{ color: var(--muted); margin-top: 6px; }

/* ================= CARDS ================= */
.card{
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: 16px;
}
.card-title{
  font-weight: 700; color:#0b1220; margin-bottom: 8px;
}
.card-muted{ color: var(--muted); }

/* Metrics */
.metric{
  display:flex; flex-direction:column; gap:6px;
}
.metric .label{
  font-size: .8rem; letter-spacing: .08em; color: var(--muted); text-transform: uppercase;
}
.metric .value{
  font-size: 1.4rem; font-weight: 800; color: #0b1220;
}

/* ================= GRID ================= */
.grid-2{ display:grid; grid-template-columns: 1fr; gap: 16px; }
.grid-3{ display:grid; grid-template-columns: 1fr; gap: 16px; }
@media (min-width: 768px){
  .grid-2{ grid-template-columns: repeat(2,minmax(0,1fr)); }
}
@media (min-width: 1024px){
  .grid-3{ grid-template-columns: repeat(3,minmax(0,1fr)); }
}

/* ================= BUTTONS ================= */
.btn{
  display:inline-flex; align-items:center; justify-content:center; gap:8px;
  font-weight:600; border-radius: 10px; padding: 10px 14px;
  border: 1px solid var(--border); background: var(--surface); color: #0b1220;
  box-shadow: var(--shadow-xs); cursor:pointer;
}
.btn:hover{ background: var(--surface-2); }
.btn-primary{
  background: var(--primary); color: #fff; border-color: var(--primary);
}
.btn-primary:hover{ background: var(--primary-600); }
.btn-outline{
  background: transparent; color: var(--primary);
  border-color: var(--primary);
}
.btn-danger{ background: var(--danger); color: #fff; border-color: var(--danger); }
.btn-success{ background: var(--success); color:#fff; border-color: var(--success); }

/* ================= FORMS ================= */
.form-card{
  background: var(--surface); border:1px solid var(--border); border-radius: var(--radius-xl);
  padding: 18px; box-shadow: var(--shadow-sm); max-width: 560px; margin: 0 auto 16px;
}
.form-card h2{ margin:0 0 8px; font-size: var(--fs-xl); }
.form-row{ display:grid; gap: 10px; }
@media (min-width: 640px){ .form-row.grid-2{ grid-template-columns: repeat(2,minmax(0,1fr)); } }
.form-group{ display:flex; flex-direction:column; gap:6px; }
.form-group label{ font-size: .85rem; color: var(--muted); }
.form-group input,
.form-group textarea,
.form-group select{
  width: 100%; padding: 10px 12px; border-radius: 10px;
  border: 1px solid var(--border); background: #fff; color: var(--text);
  font-size: .95rem; outline: none;
}
.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus{
  border-color: var(--primary); box-shadow: 0 0 0 4px var(--primary-50);
}

/* Inline alerts */
.alert{
  border-radius: 10px; padding: 10px 12px; font-size: .92rem; margin: 8px 0;
  border: 1px solid var(--border); background: #fff;
}
.alert.success{ border-color: rgba(22,163,74,.2); background: #f0fdf4; color:#14532d; }
.alert.warn{ border-color: rgba(245,158,11,.25); background: #fffbeb; color:#7c2d12; }
.alert.error{ border-color: rgba(220,38,38,.2); background: #fef2f2; color:#7f1d1d; }

/* ================= TABLES ================= */
.table-wrap{
  border:1px solid var(--border); border-radius: var(--radius-lg);
  background: var(--surface); overflow: hidden; box-shadow: var(--shadow-sm);
}
.table-responsive{ width:100%; overflow-x:auto; }
table{ width:100%; border-collapse: collapse; min-width: 720px; }
th,td{ padding: 12px 12px; border-bottom: 1px solid var(--border); }
th{ font-size:.8rem; color: var(--muted); font-weight:600; text-align:left; }
tr:hover td{ background: #f9fafb; }

/* Stacked table style for very small screens (optional) */
@media (max-width: 480px){
  table.stack{ min-width: 0; }
  table.stack thead{ display:none; }
  table.stack tr{ display:block; border-bottom: 1px solid var(--border); }
  table.stack td{
    display:grid; grid-template-columns: 120px 1fr;
    gap:8px; padding:10px 12px;
  }
  table.stack td::before{
    content: attr(data-label);
    color: var(--muted); font-size: .8rem;
  }
}

/* ================= BADGES / CHIPS ================= */
.badge{
  display:inline-flex; align-items:center; gap:6px;
  padding: 4px 8px; border-radius: 999px; font-size: .78rem; font-weight:600;
  background: #eef2ff; color: #3730a3;
}
.badge.success{ background:#ecfdf5; color:#065f46; }
.badge.warn{ background:#fffbeb; color:#7c2d12; }
.badge.neutral{ background:#f1f5f9; color:#0f172a; }

/* ================= FOOTER ================= */
.footer{
  border-top:1px solid var(--border);
  background: #fff; color: var(--muted);
  padding: 16px 0; font-size: .85rem;
}

/* ================= UTILITIES ================= */
.m-0{ margin:0!important; } .mt-6{ margin-top:6px!important; }
.mt-12{ margin-top:12px!important; } .mt-16{ margin-top:16px!important; }
.mt-20{ margin-top:20px!important; } .mb-12{ margin-bottom:12px!important; }
.w-full{ width:100%; } .text-muted{ color: var(--muted); }
.center{ display:flex; align-items:center; justify-content:center; }

/* ================= SPECIAL SECTIONS ================= */

/* Admin KPI grid quick polish */
.kpi{
  display:grid; grid-template-columns: 1fr; gap: 12px; margin: 12px 0 18px;
}
@media (min-width: 768px){ .kpi{ grid-template-columns: repeat(4,minmax(0,1fr)); } }
.kpi .card{ padding:16px; }
.kpi .value{ font-size: 1.25rem; font-weight: 800; }

/* Hero variations for homepage */
.hero-card{
  background: linear-gradient(180deg, #ffffff, #f8fbff);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-md);
  padding: 16px;
}

/* Catalog cards */
.catalog{
  display:grid; gap: 12px; grid-template-columns: 1fr;
}
@media (min-width: 640px){ .catalog{ grid-template-columns: repeat(2,minmax(0,1fr)); } }
@media (min-width: 1024px){ .catalog{ grid-template-columns: repeat(3,minmax(0,1fr)); } }
.catalog .card .price{
  font-weight: 800; color:#0b1220; font-size: 1rem;
}
.catalog .card p{ color: var(--muted); }

/* Nav spacer under sticky header */
.nav-spacer{ height: 6px; }