/* ============================================================
   BookTrack — Modern UI
   ============================================================ */

:root {
  /* Brand */
  --brand-50:  #eef4ff;
  --brand-100: #d9e6ff;
  --brand-500: #2563eb;
  --brand-600: #1d4ed8;
  --brand-700: #1e40af;
  --brand-800: #1e3a8a;

  /* Semantic */
  --ok-50:  #ecfdf5;
  --ok-500: #10b981;
  --ok-700: #047857;
  --warn-50:  #fffbeb;
  --warn-500: #f59e0b;
  --warn-700: #b45309;
  --danger-50:  #fef2f2;
  --danger-500: #ef4444;
  --danger-600: #dc2626;
  --danger-700: #b91c1c;

  /* Neutrals */
  --bg:         #f6f8fb;
  --surface:    #ffffff;
  --surface-2:  #f3f4f6;
  --border:     #e5e7eb;
  --border-strong: #d1d5db;
  --ink:        #111827;
  --ink-2:      #374151;
  --ink-3:      #6b7280;
  --ink-muted:  #9ca3af;

  /* Typography */
  --font-ui: "Sarabun", "Inter", -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  --font-mono: "JetBrains Mono", "Consolas", "Courier New", monospace;

  /* Shape */
  --r-sm: 6px;
  --r-md: 10px;
  --r-lg: 14px;
  --r-xl: 20px;

  /* Elevation */
  --shadow-xs: 0 1px 2px rgba(17,24,39,0.04);
  --shadow-sm: 0 1px 3px rgba(17,24,39,0.08), 0 1px 2px rgba(17,24,39,0.04);
  --shadow-md: 0 4px 12px rgba(17,24,39,0.08), 0 2px 4px rgba(17,24,39,0.04);
  --shadow-lg: 0 12px 28px rgba(17,24,39,0.10), 0 6px 10px rgba(17,24,39,0.04);

  /* Motion */
  --ease: cubic-bezier(0.2, 0.8, 0.2, 1);
}

* { box-sizing: border-box; }
html { font-size: 16px; }
body {
  font-family: var(--font-ui);
  margin: 0; color: var(--ink);
  background: var(--bg);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--brand-600); text-decoration: none; }
a:hover { color: var(--brand-700); text-decoration: underline; }

code, pre { font-family: var(--font-mono); font-size: 0.92em; }
code {
  background: var(--surface-2); color: var(--ink-2);
  padding: 0.12rem 0.4rem; border-radius: 4px;
  border: 1px solid var(--border);
}

/* ============================================================
   Layout
   ============================================================ */
.topbar {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; gap: 1.2rem;
  padding: 0.65rem 1.2rem;
  background: rgba(255,255,255,0.85);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.topbar .brand a {
  font-weight: 700; font-size: 1.2rem;
  color: var(--ink); display: flex; align-items: center; gap: 0.4rem;
}
.topbar .brand a:hover { text-decoration: none; color: var(--brand-700); }
.topbar nav {
  display: flex; flex-wrap: wrap; gap: 0.25rem; flex: 1;
}
.topbar nav a {
  padding: 0.4rem 0.75rem;
  border-radius: var(--r-sm);
  color: var(--ink-2);
  font-size: 0.97rem;
  transition: background 0.15s var(--ease), color 0.15s var(--ease);
}
.topbar nav a:hover {
  background: var(--surface-2); color: var(--ink);
  text-decoration: none;
}
.topbar .user {
  display: flex; gap: 0.5rem; align-items: center;
  font-size: 0.92rem; color: var(--ink-3);
}
.topbar .user a {
  padding: 0.35rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: var(--r-sm);
  color: var(--ink-2);
}
.topbar .user a:hover { background: var(--surface-2); text-decoration: none; }

main { max-width: 1180px; margin: 1.5rem auto; padding: 0 1.4rem; }
footer {
  text-align: center; padding: 2rem 1rem; color: var(--ink-muted);
  font-size: 0.88rem;
}

/* ============================================================
   Typography
   ============================================================ */
h1 { font-size: 1.75rem; margin: 0.25rem 0 1rem; letter-spacing: -0.01em; }
h2 { font-size: 1.2rem; margin: 0 0 0.75rem; letter-spacing: -0.01em; }
h3 { font-size: 1.05rem; margin: 0.5rem 0 0.5rem; }
.muted { color: var(--ink-3); font-size: 0.92rem; }
small { font-size: 0.85rem; color: var(--ink-3); }

/* ============================================================
   Cards / sections
   ============================================================ */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  padding: 1.1rem 1.35rem;
  margin-bottom: 1.1rem;
  box-shadow: var(--shadow-xs);
  transition: box-shadow 0.2s var(--ease);
}
.card:hover { box-shadow: var(--shadow-sm); }

/* ============================================================
   Buttons
   ============================================================ */
button, .btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 0.4rem;
  font-family: inherit;
  font-size: 0.95rem; font-weight: 500;
  padding: 0.55rem 1rem;
  border-radius: var(--r-md);
  border: 1px solid transparent;
  cursor: pointer;
  background: var(--brand-600); color: #fff;
  box-shadow: var(--shadow-xs);
  transition: transform 0.08s var(--ease), box-shadow 0.15s var(--ease), background 0.15s var(--ease), border 0.15s var(--ease);
  text-decoration: none;
  line-height: 1.2;
}
button:hover, .btn:hover { background: var(--brand-700); box-shadow: var(--shadow-sm); text-decoration: none; }
button:active, .btn:active { transform: translateY(1px); }
button:focus-visible, .btn:focus-visible {
  outline: 3px solid var(--brand-100); outline-offset: 1px;
}

.btn-primary { background: var(--brand-600); color: #fff; }
.btn-primary:hover { background: var(--brand-700); }

.btn-outline {
  background: var(--surface); color: var(--ink-2);
  border-color: var(--border-strong);
}
.btn-outline:hover { background: var(--surface-2); border-color: var(--ink-3); color: var(--ink); }

.btn-ghost {
  background: transparent; color: var(--ink-2);
  border-color: transparent; box-shadow: none;
}
.btn-ghost:hover { background: var(--surface-2); }

.btn-danger { background: var(--danger-600); color: #fff; }
.btn-danger:hover { background: var(--danger-700); }

.btn-warning { background: var(--warn-500); color: #1f2937; }
.btn-warning:hover { background: #e09800; color: #111827; }

.btn-success { background: var(--ok-500); color: #fff; }
.btn-success:hover { background: var(--ok-700); }

.btn-sm { padding: 0.3rem 0.65rem; font-size: 0.85rem; border-radius: var(--r-sm); }

/* legacy support — old buttons named btn-small */
.btn-small { padding: 0.3rem 0.65rem; font-size: 0.85rem; border-radius: var(--r-sm); }

/* ============================================================
   Forms
   ============================================================ */
.form label {
  display: block; margin-bottom: 0.9rem;
  font-size: 0.95rem; color: var(--ink-2); font-weight: 500;
}
.form label.checkbox {
  display: flex; align-items: center; gap: 0.5rem;
  font-weight: 400;
}
.form label.checkbox input { width: auto; margin: 0; }
.form input, .form select, .form textarea, input, select, textarea {
  font-family: inherit; font-size: 1rem;
  padding: 0.55rem 0.75rem;
  background: var(--surface);
  border: 1px solid var(--border-strong);
  border-radius: var(--r-md);
  color: var(--ink);
  transition: border-color 0.15s var(--ease), box-shadow 0.15s var(--ease);
  width: 100%;
}
.form input:focus, .form select:focus, .form textarea:focus,
input:focus, select:focus, textarea:focus {
  outline: none;
  border-color: var(--brand-500);
  box-shadow: 0 0 0 3px var(--brand-100);
}
.form label input, .form label select, .form label textarea {
  margin-top: 0.35rem;
}
.form fieldset {
  border: 1px solid var(--border); border-radius: var(--r-md);
  padding: 1rem 1.2rem; margin-bottom: 1.1rem;
}
.form legend { padding: 0 0.5rem; font-weight: 600; color: var(--brand-700); }

.form-inline {
  display: flex; flex-wrap: wrap; gap: 0.6rem; align-items: center;
}
.form-inline input, .form-inline select {
  width: auto;
  padding: 0.5rem 0.7rem;
}

.inline { display: inline; }
.row { display: flex; gap: 0.6rem; align-items: center; flex-wrap: wrap; }

/* ============================================================
   Tables
   ============================================================ */
table.data {
  width: 100%;
  border-collapse: separate; border-spacing: 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  overflow: hidden;
  font-size: 0.95rem;
}
table.data th, table.data td {
  padding: 0.7rem 0.9rem; text-align: left;
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
}
table.data tr:last-child td { border-bottom: none; }
table.data th {
  background: var(--surface-2);
  font-weight: 600; color: var(--ink-2);
  font-size: 0.9rem;
  letter-spacing: 0.01em;
}
table.data tr:hover td { background: #fafbfc; }
tr.overdue { background: var(--danger-50); }
tr.err     { background: var(--danger-50); }
tr.row-disabled td { opacity: 0.55; }
.action-col { white-space: nowrap; }
.actions {
  display: inline-flex; align-items: center;
  gap: 0.35rem; flex-wrap: nowrap;
}
.actions .inline { display: inline-flex; margin: 0; }
.actions .btn, .actions .btn-sm, .actions button {
  padding: 0.3rem 0.55rem;
  white-space: nowrap;
  line-height: 1.15;
}

/* ============================================================
   Tags / chips
   ============================================================ */
.tag {
  display: inline-flex; align-items: center; gap: 0.25rem;
  padding: 0.15rem 0.6rem;
  border-radius: 999px;
  font-size: 0.8rem; font-weight: 500;
  border: 1px solid transparent;
}
.tag-green { background: var(--ok-50);    color: var(--ok-700);    border-color: #bbf7d0; }
.tag-red   { background: var(--danger-50);color: var(--danger-700);border-color: #fecaca; }
.tag-amber { background: var(--warn-50);  color: var(--warn-700);  border-color: #fde68a; }
.tag-blue  { background: var(--brand-50); color: var(--brand-700); border-color: #bfdbfe; }
.tag-gray  { background: var(--surface-2);color: var(--ink-3);     border-color: var(--border); }

/* legacy compatibility */
.tag-red, .tag-gray { display: inline-flex; }

/* ============================================================
   Alerts
   ============================================================ */
.alert {
  padding: 0.75rem 1rem;
  border-radius: var(--r-md);
  margin-bottom: 1rem;
  font-size: 0.95rem;
  border: 1px solid transparent;
}
.alert-success { background: var(--ok-50);     color: var(--ok-700);    border-color: #a7f3d0; }
.alert-error   { background: var(--danger-50); color: var(--danger-700); border-color: #fecaca; }
.alert-warn    { background: var(--warn-50);   color: var(--warn-700);  border-color: #fde68a; }
.err           { background: var(--danger-50); color: var(--danger-700); border: 1px solid #fecaca; padding: 0.75rem 1rem; border-radius: var(--r-md); margin-bottom: 1rem; }

/* ============================================================
   Details / summary
   ============================================================ */
details {
  margin-top: 0.8rem;
  border-top: 1px solid var(--border); padding-top: 0.6rem;
}
summary {
  cursor: pointer; padding: 0.45rem 0;
  font-size: 1rem; font-weight: 500; color: var(--brand-700);
  list-style: none;
}
summary::-webkit-details-marker { display: none; }
summary::before { content: "▸ "; transition: transform 0.15s var(--ease); display: inline-block; }
details[open] > summary::before { transform: rotate(90deg); }

/* ============================================================
   Login
   ============================================================ */
.login-body {
  display: flex; align-items: center; justify-content: center;
  min-height: 100vh;
  background: linear-gradient(135deg, var(--brand-50) 0%, #fff 50%, var(--ok-50) 100%);
}
.login-box {
  background: var(--surface);
  padding: 2.4rem 2.6rem;
  border-radius: var(--r-xl);
  min-width: 380px; max-width: 440px;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border);
}
.login-box h1 { margin-top: 0; font-size: 1.7rem; text-align: center; }
.login-box > p { text-align: center; margin-top: -0.3rem; }
.login-box label { display: block; margin-bottom: 1rem; }
.login-box input { margin-top: 0.3rem; }
.login-box button { width: 100%; padding: 0.75rem; margin-top: 0.6rem; font-size: 1.02rem; }

/* ============================================================
   Calendar legend
   ============================================================ */
.cal-legend {
  display: flex; flex-wrap: wrap; gap: 0.4rem;
  padding: 0.7rem 0.9rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
}
.cal-chip {
  display: inline-flex; align-items: center; gap: 0.4rem;
  font-size: 0.88rem;
  padding: 0.2rem 0.6rem;
  background: var(--surface-2); border-radius: 999px;
  border: 1px solid var(--border);
}
.swatch {
  display: inline-block; width: 10px; height: 10px;
  border-radius: 50%;
  border: 1px solid rgba(0,0,0,0.08);
}

/* ============================================================
   View toggle pills
   ============================================================ */
.view-toggle {
  display: inline-flex; gap: 0.25rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 0.25rem;
}
.view-toggle a, .view-toggle > span {
  padding: 0.4rem 0.85rem;
  border-radius: var(--r-sm);
  font-size: 0.9rem;
  color: var(--ink-2); text-decoration: none;
}
.view-toggle a:hover { background: var(--surface-2); text-decoration: none; }
.view-toggle > span {
  background: var(--brand-600) !important;
  color: #fff !important;
  font-weight: 500;
}

/* ============================================================
   Month grid
   ============================================================ */
.month-grid {
  width: 100%;
  border-collapse: separate; border-spacing: 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  overflow: hidden;
  table-layout: fixed;
}
.month-grid th {
  background: var(--surface-2);
  padding: 0.55rem; border-bottom: 1px solid var(--border);
  text-align: center; font-size: 0.88rem; font-weight: 600;
  color: var(--ink-2);
}
.month-grid td {
  width: 14.28%; height: 130px; vertical-align: top;
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 0.4rem 0.45rem;
  font-size: 0.85rem; overflow: hidden;
  background: var(--surface);
  transition: background 0.1s var(--ease);
}
.month-grid tr td:last-child { border-right: none; }
.month-grid tbody tr:last-child td { border-bottom: none; }
.month-grid td:hover { background: #fafbfc; }
.month-grid .day-num {
  font-weight: 600; color: var(--ink-2); font-size: 0.95rem;
  margin-bottom: 0.3rem;
}
.month-grid .other-month { background: #fafbfc; }
.month-grid .other-month .day-num { color: var(--ink-muted); font-weight: 400; }
.month-grid .today {
  background: var(--warn-50);
  position: relative;
}
.month-grid .today .day-num {
  display: inline-flex; align-items: center; justify-content: center;
  width: 26px; height: 26px;
  background: var(--warn-500); color: #fff;
  border-radius: 50%; font-size: 0.82rem;
}
.month-grid .event {
  background: var(--brand-50); color: var(--brand-800);
  padding: 0.15rem 0.45rem;
  border-radius: 4px;
  margin-bottom: 0.18rem;
  font-size: 0.78rem; line-height: 1.35;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
  cursor: default;
  border-left: 3px solid var(--brand-600);
  transition: filter 0.1s var(--ease);
}
.month-grid .event:hover { filter: brightness(0.95); }
.month-grid .event .time {
  font-weight: 600; margin-right: 0.25rem; color: var(--brand-700);
}

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 900px) {
  .month-grid td { height: 95px; font-size: 0.76rem; padding: 0.25rem; }
  .month-grid .event { font-size: 0.7rem; padding: 0.08rem 0.3rem; }
  .month-grid .day-num { font-size: 0.85rem; }
}
@media (max-width: 700px) {
  html { font-size: 15px; }
  .topbar { flex-wrap: wrap; padding: 0.55rem 0.7rem; }
  .topbar nav { order: 3; flex-basis: 100%; gap: 0.15rem; margin-top: 0.4rem; }
  .topbar nav a { padding: 0.3rem 0.55rem; font-size: 0.9rem; }
  main { padding: 0 0.8rem; }
  .card { padding: 0.9rem 1rem; }
  table.data { font-size: 0.9rem; }
  table.data th, table.data td { padding: 0.5rem 0.5rem; }
  .login-box { min-width: auto; width: calc(100% - 2rem); padding: 1.6rem; }
}