:root{
  --bg:#f5f6f8;
  --bg-elevated:#ffffff;
  --text:#1a1d23;
  --text-muted:#6b7280;
  --border:#e2e5ea;
  --accent:#2563eb;
  --accent-contrast:#ffffff;
  --danger:#dc2626;
  --today-ring:#2563eb;
  --shadow:0 4px 16px rgba(0,0,0,.08);
  --radius:10px;
  --today-tint:rgba(37,99,235,.06);
}
[data-theme="dark"]{
  --bg:#14161a;
  --bg-elevated:#1e2128;
  --text:#e7e9ee;
  --text-muted:#9aa1ad;
  --border:#2c3038;
  --accent:#5b8cff;
  --accent-contrast:#0b0d10;
  --danger:#f87171;
  --today-ring:#5b8cff;
  --shadow:0 4px 20px rgba(0,0,0,.4);
  --today-tint:rgba(91,140,255,.12);
}
*{box-sizing:border-box}
html,body{margin:0;height:100%}
body{
  background:var(--bg);
  color:var(--text);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  font-size:14px;
}
button,input,select,textarea{font-family:inherit;font-size:inherit;color:inherit}
h1,h2,h3{margin:0}
.hidden{display:none!important}

/* Header */
.app-header{
  display:flex;align-items:center;gap:12px;flex-wrap:wrap;
  padding:10px 16px;background:var(--bg-elevated);border-bottom:1px solid var(--border);
  position:sticky;top:0;z-index:20;
}
.header-left{display:flex;align-items:center;gap:8px}
.header-center{display:flex;align-items:center;gap:6px;margin-left:8px}
.header-right{display:flex;align-items:center;gap:8px;margin-left:auto;flex-wrap:wrap}
.app-title{font-size:18px;white-space:nowrap}
.month-label{font-size:16px;min-width:170px;text-transform:capitalize}

.icon-btn{
  background:transparent;border:1px solid transparent;border-radius:8px;
  width:32px;height:32px;cursor:pointer;font-size:16px;line-height:1;
}
.icon-btn:hover{background:var(--bg);border-color:var(--border)}
.btn-ghost{
  background:transparent;border:1px solid var(--border);border-radius:8px;
  padding:6px 12px;cursor:pointer;
}
.btn-ghost:hover{background:var(--bg)}
.btn-primary{
  background:var(--accent);color:var(--accent-contrast);border:none;border-radius:8px;
  padding:7px 14px;cursor:pointer;font-weight:600;
}
.btn-primary:hover{filter:brightness(1.08)}
.btn-accent{background:#059669}
.btn-danger{
  background:transparent;color:var(--danger);border:1px solid var(--danger);
  border-radius:8px;padding:7px 14px;cursor:pointer;font-weight:600;
}
.btn-danger:hover{background:var(--danger);color:#fff}
.btn-block{width:100%;margin-top:12px}

.view-toggle{display:flex;border:1px solid var(--border);border-radius:8px;overflow:hidden}
.view-btn{background:var(--bg-elevated);border:none;padding:6px 12px;cursor:pointer}
.view-btn.active{background:var(--accent);color:var(--accent-contrast)}
.search-input{
  border:1px solid var(--border);border-radius:8px;padding:6px 10px;background:var(--bg);width:180px;
}

/* Side menu */
.side-menu{
  position:fixed;top:0;left:0;bottom:0;width:260px;background:var(--bg-elevated);
  border-right:1px solid var(--border);z-index:40;padding:12px;box-shadow:var(--shadow);
  display:flex;flex-direction:column;gap:4px;
}
.side-menu-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:10px}
.menu-item{
  text-align:left;background:transparent;border:none;padding:10px 12px;border-radius:8px;
  cursor:pointer;font-size:14px;
}
.menu-item:hover{background:var(--bg)}
.overlay{position:fixed;inset:0;background:rgba(0,0,0,.35);z-index:30}

/* Calendar grid */
.app-main{padding:16px;max-width:1200px;margin:0 auto}
.month-grid{
  display:grid;grid-template-columns:repeat(7,1fr);gap:6px;
}
.weekday-header{
  text-align:center;font-weight:600;color:var(--text-muted);padding:6px 0;font-size:12px;
  text-transform:uppercase;letter-spacing:.03em;
}
.day-cell{
  background:var(--bg-elevated);border:1px solid var(--border);border-radius:var(--radius);
  min-height:110px;padding:6px;display:flex;flex-direction:column;gap:4px;cursor:pointer;
  transition:box-shadow .15s;
}
.day-cell:hover{box-shadow:var(--shadow)}
.day-cell.other-month{opacity:.4}
.day-cell.is-today{border:2px solid var(--today-ring)}
.day-cell.drag-over{outline:2px dashed var(--accent);outline-offset:-2px;background:var(--today-tint)}
.day-number{font-weight:600;font-size:13px}
.day-events{display:flex;flex-direction:column;gap:3px;overflow:hidden}
.event-chip{
  border-radius:5px;padding:2px 6px;font-size:11.5px;color:#fff;white-space:nowrap;
  overflow:hidden;text-overflow:ellipsis;cursor:grab;
}
.event-chip:active{cursor:grabbing}
.event-more{font-size:11px;color:var(--text-muted);cursor:pointer;padding:2px 6px}

/* Week view */
.week-view{overflow-x:auto}
.week-grid-header{
  display:grid;grid-template-columns:60px repeat(7,1fr);min-width:700px;
  position:sticky;top:0;background:var(--bg);z-index:5;border-bottom:1px solid var(--border);
}
.week-day-header-cell{padding:6px 4px;text-align:center;border-left:1px solid var(--border);cursor:pointer}
.week-day-header-cell:hover{background:var(--bg-elevated)}
.week-day-header-cell.is-today .week-day-number{color:var(--accent)}
.week-day-name{font-size:11px;color:var(--text-muted);text-transform:uppercase;letter-spacing:.03em}
.week-day-number{font-size:16px;font-weight:700}
.week-allday-list{display:flex;flex-direction:column;gap:2px;margin-top:4px}
.week-allday-list .event-chip{font-size:10.5px;text-align:left}
.week-grid-body{display:flex;position:relative;min-width:700px}
.week-gutter{width:60px;flex-shrink:0;position:relative}
.week-hour-label{position:absolute;left:0;right:6px;top:0;text-align:right;font-size:11px;color:var(--text-muted);transform:translateY(-50%)}
.week-columns{flex:1;display:grid;grid-template-columns:repeat(7,1fr);position:relative}
.week-day-col{position:relative;border-left:1px solid var(--border);cursor:pointer}
.week-day-col.is-today{background:var(--today-tint)}
.week-day-col.drag-over{outline:2px dashed var(--accent);outline-offset:-2px}
.week-day-header-cell.drag-over{outline:2px dashed var(--accent);outline-offset:-2px}
.week-hour-line{position:absolute;left:0;right:0;top:0;border-top:1px solid var(--border)}
.week-event{
  position:absolute;border-radius:6px;color:#fff;padding:3px 6px;overflow:hidden;
  font-size:11px;cursor:grab;box-shadow:0 1px 3px rgba(0,0,0,.25);
}
.week-event:active{cursor:grabbing}
.week-event-title{font-weight:600;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.week-event-time{font-size:10px;opacity:.9}
.week-event-resize-handle{
  position:absolute;left:0;right:0;bottom:0;height:7px;cursor:ns-resize;
}
.week-event-resize-handle::after{
  content:"";position:absolute;left:50%;bottom:2px;width:20px;height:3px;
  transform:translateX(-50%);border-radius:2px;background:rgba(255,255,255,0);
}
.week-event-resize-handle:hover::after{background:rgba(255,255,255,.6)}

/* Agenda view */
.agenda-view{display:flex;flex-direction:column;gap:16px}
.agenda-day-group{background:var(--bg-elevated);border:1px solid var(--border);border-radius:var(--radius);padding:12px}
.agenda-day-title{font-weight:700;margin-bottom:8px;text-transform:capitalize}
.agenda-item{display:flex;gap:10px;align-items:flex-start;padding:8px 4px;border-top:1px solid var(--border);cursor:pointer}
.agenda-item:first-child{border-top:none}
.agenda-item:hover{background:var(--bg)}
.agenda-color-dot{width:10px;height:10px;border-radius:50%;margin-top:5px;flex-shrink:0}
.agenda-item-title{font-weight:600}
.agenda-item-meta{color:var(--text-muted);font-size:12px}
.empty-state{color:var(--text-muted);text-align:center;padding:40px}

/* Day panel */
.day-panel{
  position:fixed;top:0;right:0;bottom:0;width:340px;background:var(--bg-elevated);
  border-left:1px solid var(--border);z-index:40;padding:16px;box-shadow:var(--shadow);
  display:flex;flex-direction:column;overflow-y:auto;
}
.day-panel-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:10px}
.day-panel-header h3{text-transform:capitalize}
.day-panel-list{display:flex;flex-direction:column;gap:8px;flex:1}
.day-panel-item{
  border:1px solid var(--border);border-radius:8px;padding:8px 10px;cursor:pointer;
  border-left:4px solid var(--accent);
}
.day-panel-item:hover{background:var(--bg)}
.day-panel-item-title{font-weight:600}
.day-panel-item-meta{font-size:12px;color:var(--text-muted)}

/* Modals */
.modal{position:fixed;inset:0;z-index:50;display:flex;align-items:center;justify-content:center;background:rgba(0,0,0,.4);padding:16px}
.modal-box{background:var(--bg-elevated);border-radius:var(--radius);width:100%;max-width:480px;box-shadow:var(--shadow);max-height:90vh;display:flex;flex-direction:column}
.modal-box-lg{max-width:720px}
.modal-header{display:flex;justify-content:space-between;align-items:center;padding:14px 16px;border-bottom:1px solid var(--border)}
.modal-body{padding:16px;overflow-y:auto;display:flex;flex-direction:column;gap:12px}
.modal-body label{display:flex;flex-direction:column;gap:4px;font-size:13px;font-weight:500;flex:1}
.modal-body input[type=text],.modal-body input[type=date],.modal-body input[type=time],
.modal-body select,.modal-body textarea{
  border:1px solid var(--border);border-radius:8px;padding:8px 10px;background:var(--bg);font-weight:400;
}
.checkbox-label{flex-direction:row!important;align-items:center;gap:6px!important}
.form-row{display:flex;gap:10px}
.modal-footer{display:flex;gap:8px;align-items:center;padding-top:6px}
.spacer{flex:1}

.recurrence-fieldset{border:1px solid var(--border);border-radius:8px;padding:10px}
.recurrence-options{display:flex;flex-direction:column;gap:10px;margin-top:8px}
.weekday-picker{display:flex;gap:8px;flex-wrap:wrap;font-size:12px}
.weekday-picker label{flex-direction:row!important;align-items:center;gap:4px!important}

.categories-list{display:flex;flex-direction:column;gap:8px}
.category-row{display:flex;align-items:center;gap:8px}
.category-row input[type=text]{flex:1}
.new-category-row{align-items:center}

.danger-zone-label{color:var(--danger);font-weight:600;font-size:12px;text-transform:uppercase}
.hint-text{font-size:12px;color:var(--text-muted);background:var(--bg);border-radius:8px;padding:8px 10px;margin:0}
.conflict-warning{font-size:12px;color:var(--danger);margin-top:6px}

@media (max-width:760px){
  .header-center,.header-right{width:100%;justify-content:space-between}
  .search-input{width:100%}
  .day-panel{width:100%}
}