@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700&family=Noto+Sans+KR:wght@400;500;600;700&display=swap');

:root {
  color-scheme: light;
  font-family: 'DM Sans', 'Noto Sans KR', sans-serif;
  color: #20283b;
  background: #f4f6fb;
  font-synthesis: none;
  --page: #f4f6fb;
  --glow: #e6edff;
  --card: #fff;
  --text: #20283b;
  --muted: #8991a3;
  --border: #e8ebf2;
  --soft-border: #edf0f5;
  --field: #fff;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  color: #e8ebf4;
  background: #171b27;
  --page: #171b27;
  --glow: #252d45;
  --card: #202635;
  --text: #e8ebf4;
  --muted: #a0a9bd;
  --border: #343c4f;
  --soft-border: #343c4f;
  --field: #191f2d;
}

* { box-sizing: border-box; }

body {
  min-height: 100vh;
  margin: 0;
  display: grid;
  place-items: center;
  padding: 28px 16px;
  color: var(--text);
  background: radial-gradient(circle at 15% 10%, var(--glow) 0, transparent 32%), var(--page);
  transition: background .2s, color .2s;
}

.todo-card {
  width: min(100%, 560px);
  padding: 38px;
  border: 1px solid var(--border);
  border-radius: 24px;
  background: var(--card);
  box-shadow: 0 20px 60px #24365b12;
  transition: background .2s, border-color .2s;
}

header { margin-bottom: 28px; }
.topline { display: flex; align-items: center; justify-content: space-between; margin-bottom: 10px; }
.eyebrow { margin: 0; color: #667eea; font-size: 11px; font-weight: 700; letter-spacing: .16em; }
h1 { margin: 0; font-size: 30px; letter-spacing: -.05em; }
.subtitle { margin: 8px 0 0; color: var(--muted); font-size: 14px; }
.theme-toggle { padding: 7px 10px; border: 1px solid var(--border); border-radius: 9px; background: var(--field); color: var(--text); font-size: 12px; }

.calendar-panel { margin: 0 0 25px; padding: 16px; border: 1px solid var(--border); border-radius: 14px; background: color-mix(in srgb, var(--field) 70%, var(--card)); }
.calendar-topline, .calendar-controls { display: flex; align-items: center; }
.calendar-topline { justify-content: space-between; margin-bottom: 14px; }
.calendar-topline h2 { font-size: 14px; }
.calendar-controls { gap: 6px; color: var(--text); font-size: 13px; }
.calendar-controls button { width: 28px; height: 28px; border: 1px solid var(--border); border-radius: 8px; background: var(--field); color: var(--text); }
.calendar-controls .today-button { width: auto; padding: 0 8px; font-size: 11px; }
#calendar-month { min-width: 94px; text-align: center; font-weight: 600; }
.calendar-weekdays, .calendar-grid { display: grid; grid-template-columns: repeat(7, minmax(0, 1fr)); text-align: center; }
.calendar-weekdays { margin-bottom: 5px; color: var(--muted); font-size: 11px; }
.calendar-day { position: relative; justify-self: center; width: 32px; height: 32px; padding: 0; border: 0; border-radius: 50%; background: transparent; color: var(--text); font: inherit; font-size: 12px; }
.calendar-day:not(:disabled):hover { background: var(--glow); }
.calendar-day:disabled { visibility: hidden; }
.calendar-day.today { box-shadow: inset 0 0 0 1px #8292e8; }
.calendar-day.selected { background: #667eea; color: #fff; box-shadow: none; }
.calendar-day.has-todos:not(.selected)::after { position: absolute; bottom: 2px; left: 50%; width: 4px; height: 4px; border-radius: 50%; background: #667eea; content: ''; transform: translateX(-50%); }
.selected-date-label { margin: 11px 0 0; color: var(--muted); font-size: 11px; text-align: right; }

.add-form { display: flex; gap: 9px; margin-bottom: 30px; }
.add-form input, .add-form select {
  min-width: 0;
  padding: 13px 12px;
  border: 1px solid var(--border);
  border-radius: 11px;
  outline: none;
  background: var(--field);
  color: var(--text);
  font: inherit;
  font-size: 14px;
  transition: border-color .15s, box-shadow .15s;
}
.add-form input { flex: 1; }
.add-form select { cursor: pointer; }
.add-form input:focus, .add-form select:focus { border-color: #7185e8; box-shadow: 0 0 0 3px #7185e81c; }
.add-form input::placeholder { color: #aab0bd; }
button { font: inherit; cursor: pointer; }
.add-form > button { padding: 0 18px; border: 0; border-radius: 11px; background: #667eea; color: #fff; font-size: 14px; font-weight: 600; transition: background .15s, transform .15s; }
.add-form > button:hover { background: #536bd9; }
.add-form > button:active { transform: scale(.97); }

.list-heading { display: flex; align-items: center; justify-content: space-between; margin-bottom: 16px; }
h2 { margin: 0; font-size: 15px; font-weight: 700; }
.count, .group-count { color: var(--muted); font-size: 12px; }
.todo-group + .todo-group { margin-top: 22px; }
h3 { display: flex; align-items: center; gap: 7px; margin: 0 0 9px; color: var(--muted); font-size: 12px; font-weight: 600; }
.todo-list { display: grid; gap: 8px; margin: 0; padding: 0; list-style: none; }
.todo-item { display: flex; align-items: center; gap: 10px; min-height: 52px; padding: 10px 12px; border: 1px solid var(--soft-border); border-radius: 12px; }
.todo-item input { flex: 0 0 auto; width: 17px; height: 17px; margin: 0; accent-color: #667eea; cursor: pointer; }
.todo-text { flex: 1; min-width: 0; overflow-wrap: anywhere; font-size: 14px; }
.todo-item.done .todo-text { color: var(--muted); text-decoration: line-through; }
.priority { flex: 0 0 auto; padding: 4px 7px; border-radius: 7px; font-size: 10px; font-weight: 600; }
.priority-high { background: #fff0ed; color: #d45e4c; }
.priority-normal { background: #eef1ff; color: #6675c8; }
.priority-low { background: #eaf6ef; color: #538263; }
:root[data-theme="dark"] .priority-high { background: #472d32; color: #ffaaa0; }
:root[data-theme="dark"] .priority-normal { background: #303653; color: #b7c0ff; }
:root[data-theme="dark"] .priority-low { background: #293d36; color: #a2d6b6; }
.delete-button { flex: 0 0 auto; padding: 6px 8px; border: 0; border-radius: 7px; background: transparent; color: var(--muted); font-size: 12px; }
.delete-button:hover { background: #fff0f0; color: #d95d66; }
.edit-button { flex: 0 0 auto; padding: 6px 8px; border: 0; border-radius: 7px; background: transparent; color: var(--muted); font-size: 12px; }
.edit-button:hover { background: var(--glow); color: #536bd9; }
:root[data-theme="dark"] .delete-button:hover { background: #472d32; }
.empty-message { margin: 0; padding: 18px 10px; border: 1px dashed var(--border); border-radius: 12px; color: var(--muted); text-align: center; font-size: 13px; }
footer { margin-top: 26px; color: #a0a6b2; text-align: center; font-size: 11px; }
.data-management { margin-top: 28px; padding: 16px; border: 1px solid var(--border); border-radius: 14px; background: color-mix(in srgb, var(--field) 70%, var(--card)); }
.data-management-copy h2 { font-size: 14px; }
.data-management-copy p, .data-status { margin: 6px 0 0; color: var(--muted); font-size: 11px; }
.data-management-actions { display: flex; gap: 8px; margin-top: 13px; }
.data-button { flex: 1; min-height: 38px; padding: 8px 12px; border: 1px solid var(--border); border-radius: 9px; background: var(--field); color: var(--text); font-size: 12px; font-weight: 600; }
.data-button:hover { border-color: #7185e8; color: #536bd9; }
.restore-button { border-color: #667eea; background: #667eea; color: #fff; }
.restore-button:hover { background: #536bd9; color: #fff; }
.data-status:empty { display: none; }
.visually-hidden { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

@media (max-width: 520px) {
  .todo-card { padding: 28px 22px; border-radius: 20px; }
  h1 { font-size: 27px; }
  .add-form { flex-wrap: wrap; }
  .add-form input { flex-basis: 100%; }
  .add-form select { flex: 1; }
}

@media (min-width: 521px) and (max-width: 1024px) {
  .todo-card { width: min(100%, 720px); }
}

@media (max-width: 480px) {
  body { display: block; min-width: 0; padding: 12px; }
  .todo-card { width: 100%; min-width: 0; margin: 0 auto; padding: 22px 16px; }
  header { margin-bottom: 22px; }
  .topline { gap: 8px; }
  .eyebrow { font-size: 10px; }
  .theme-toggle { min-height: 40px; padding: 8px; }

  .calendar-panel { padding: 12px 8px; }
  .calendar-topline { gap: 4px; }
  .calendar-controls { gap: 3px; }
  .calendar-controls button { flex: 0 0 36px; width: 36px; height: 36px; }
  .calendar-controls .today-button { flex-basis: auto; min-width: 40px; padding: 0 7px; }
  #calendar-month { min-width: 0; font-size: 12px; }
  .calendar-weekdays { font-size: 12px; }
  .calendar-grid { row-gap: 2px; }
  .calendar-day { width: min(100%, 40px); height: 40px; font-size: 13px; }

  .add-form { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 8px; }
  .add-form input { grid-column: 1 / -1; width: 100%; min-height: 46px; }
  .add-form select, .add-form > button { width: 100%; min-height: 44px; }
  .add-form > button { padding: 0 12px; }

  .todo-item { display: grid; grid-template-columns: 24px minmax(0, 1fr) auto auto auto; gap: 5px; padding: 8px; }
  .todo-item input { width: 22px; height: 22px; }
  .todo-text { overflow-wrap: anywhere; word-break: break-word; }
  .priority { padding: 4px 5px; }
  .edit-button, .delete-button { min-width: 40px; min-height: 40px; padding: 6px 5px; }

  .data-management { padding: 14px 12px; }
  .data-management-actions { gap: 8px; }
  .data-button { min-width: 0; min-height: 44px; padding: 9px 6px; }
}

@media (max-width: 360px) {
  body { padding: 8px; }
  .todo-card { padding: 20px 12px; }
  .calendar-panel { padding-inline: 5px; }
  .calendar-controls button { flex-basis: 32px; width: 32px; height: 36px; }
  .calendar-controls .today-button { min-width: 36px; padding-inline: 5px; }
  .todo-item { grid-template-columns: 24px minmax(0, 1fr) auto auto; }
  .todo-item .priority { grid-column: 2; justify-self: start; }
  .todo-item .edit-button { grid-column: 3; grid-row: 1 / span 2; }
  .todo-item .delete-button { grid-column: 4; grid-row: 1 / span 2; }
}