:root {
  --bg: #f7f7f8;
  --surface: #ffffff;
  --border: #e2e2e6;
  --text: #1c1c1f;
  --text-dim: #6b6b72;
  --accent: #3a6df0;
  --accent-text: #ffffff;
  --danger: #d0453e;
  --today-bg: #eaf1ff;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15161a;
    --surface: #1e1f24;
    --border: #31323a;
    --text: #e9e9ee;
    --text-dim: #9a9aa4;
    --accent: #5b86ff;
    --accent-text: #0c1020;
    --danger: #ef6b64;
    --today-bg: #1d2740;
  }
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

button, input, textarea {
  font-family: inherit;
  font-size: 15px;
}

.btn {
  padding: 8px 14px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
}
.btn.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-text);
  font-weight: 600;
}
.btn.danger {
  background: transparent;
  border-color: var(--danger);
  color: var(--danger);
}
.icon-btn {
  width: 38px;
  height: 38px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: 18px;
  cursor: pointer;
}

/* Login */
.login-screen {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
}
.login-form {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 28px;
  width: 100%;
  max-width: 320px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.login-form h1 { margin: 0 0 8px; font-size: 20px; text-align: center; }
.login-form input {
  padding: 10px 12px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
}
.login-form .error { color: var(--danger); font-size: 13px; margin: 0; }

button { touch-action: manipulation; -webkit-tap-highlight-color: transparent; }

/* App shell */
.app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  height: 100dvh;
}
.toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  background: var(--surface);
  flex-wrap: wrap;
}
.toolbar-nav, .toolbar-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}
.current-label {
  margin: 0 4px;
  font-size: 16px;
  font-weight: 600;
  white-space: nowrap;
}
.view-switch {
  display: flex;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}
.view-btn {
  border: none;
  background: var(--surface);
  color: var(--text-dim);
  padding: 8px 12px;
  cursor: pointer;
  border-right: 1px solid var(--border);
}
.view-btn:last-child { border-right: none; }
.view-btn.active {
  background: var(--accent);
  color: var(--accent-text);
  font-weight: 600;
}

.view-root {
  flex: 1;
  overflow: auto;
  padding: 10px;
}

/* Month view */
.month-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
}
.month-weekday {
  background: var(--surface);
  padding: 6px 8px;
  font-size: 12px;
  color: var(--text-dim);
  text-align: center;
}
.month-cell {
  background: var(--surface);
  min-height: 90px;
  padding: 4px;
  display: flex;
  flex-direction: column;
  gap: 2px;
  cursor: pointer;
}
.month-cell.outside { opacity: 0.4; }
.month-cell.today { background: var(--today-bg); }
.month-daynum { font-size: 12px; color: var(--text-dim); padding: 2px 4px; }
.month-event {
  background: var(--accent);
  color: var(--accent-text);
  font-size: 11px;
  padding: 2px 5px;
  border-radius: 5px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* Week / day view */
.time-grid-wrap {
  display: flex;
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: clip;
  background: var(--surface);
}
.time-gutter {
  width: 52px;
  flex-shrink: 0;
  border-right: 1px solid var(--border);
}
.time-gutter .hour-label {
  height: 48px;
  font-size: 11px;
  color: var(--text-dim);
  text-align: right;
  padding-right: 6px;
  box-sizing: border-box;
  border-bottom: 1px solid var(--border);
}
.time-columns {
  display: flex;
  flex: 1;
  position: relative;
}
.time-day-col {
  flex: 1;
  position: relative;
  border-right: 1px solid var(--border);
  min-width: 90px;
}
.time-day-col:last-child { border-right: none; }
.time-day-header {
  text-align: center;
  font-size: 12px;
  color: var(--text-dim);
  padding: 6px 0;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--surface);
}
.time-day-header.today { color: var(--accent); font-weight: 700; }
.hour-row {
  height: 48px;
  border-bottom: 1px solid var(--border);
}
.time-event {
  position: absolute;
  left: 3px;
  right: 3px;
  background: var(--accent);
  color: var(--accent-text);
  border-radius: 6px;
  font-size: 12px;
  padding: 3px 6px;
  overflow: hidden;
  cursor: pointer;
}
.all-day-row {
  border-bottom: 1px solid var(--border);
  padding: 4px;
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
}
.all-day-row .month-event { cursor: pointer; }

/* Modal */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  z-index: 50;
}
.modal {
  background: var(--surface);
  border-radius: 14px;
  padding: 20px;
  width: 100%;
  max-width: 420px;
  max-height: 90vh;
  overflow: auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.modal h3 { margin: 0; }
.modal label {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 13px;
  color: var(--text-dim);
  flex: 1;
  min-width: 0;
}
.modal input, .modal textarea {
  width: 100%;
  min-width: 0;
  padding: 9px 10px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
}
.modal .row { display: flex; gap: 10px; }
.modal .checkbox-row { flex-direction: row; align-items: center; gap: 6px; font-size: 14px; color: var(--text); }
.modal .checkbox-row input { width: auto; }
.modal-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 4px;
}
.modal-actions .spacer { flex: 1; }

@media (max-width: 640px) {
  .toolbar { padding: 8px 10px; gap: 8px; }
  .toolbar-nav { width: 100%; }
  .current-label { flex: 1; text-align: center; font-size: 15px; }
  .toolbar-actions { width: 100%; justify-content: space-between; }
  .toolbar-actions .btn, .view-btn { padding: 8px 10px; font-size: 14px; }
  .view-root { padding: 6px; }
  .month-cell { min-height: 64px; padding: 2px; }
  .month-event { font-size: 10px; padding: 1px 3px; }
  .time-gutter { width: 42px; }
  .time-gutter .hour-label { font-size: 10px; padding-right: 4px; }
  .time-day-col { min-width: 0; }
  .modal .row { flex-direction: column; }
}