*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #0d1117;
  --surface: #161b22;
  --surface2: #1e2530;
  --border: #30363d;
  --text: #e6edf3;
  --muted: #7d8590;
  --today-ring: #f0c040;

  --cat-tarea: #4ade80;
  --cat-parcial: #fb923c;
  --cat-ccna: #60a5fa;
  --cat-proyecto: #c084fc;
  --cat-personal: #fb7185;

  --cat-tarea-bg: rgba(74, 222, 128, 0.12);
  --cat-parcial-bg: rgba(251, 146, 60, 0.12);
  --cat-ccna-bg: rgba(96, 165, 250, 0.12);
  --cat-proyecto-bg: rgba(192, 132, 252, 0.12);
  --cat-personal-bg: rgba(251, 113, 133, 0.12);
}

html {
  font-size: 15px;
}
body {
  background: var(--bg);
  color: var(--text);
  font-family: "DM Sans", sans-serif;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ── Auth screen ── */
#auth-screen {
  position: fixed;
  inset: 0;
  background: var(--bg);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 200;
  padding: 1rem;
}
#auth-screen.hidden {
  display: none;
}

.auth-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 2rem;
  width: 100%;
  max-width: 380px;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}
.auth-brand {
  font-family: "Playfair Display", serif;
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  text-align: center;
}
.auth-brand span {
  color: var(--today-ring);
}
.auth-tagline {
  font-size: 0.78rem;
  color: var(--muted);
  text-align: center;
  font-family: "DM Mono", monospace;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-top: -0.75rem;
}

.auth-tabs {
  display: flex;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}
.auth-tab {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--muted);
  padding: 0.55rem;
  cursor: pointer;
  font-family: "DM Sans", sans-serif;
  font-size: 0.85rem;
  transition:
    background 0.15s,
    color 0.15s;
}
.auth-tab.active {
  background: var(--surface2);
  color: var(--text);
}

.auth-fields {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.auth-error {
  font-size: 0.78rem;
  color: var(--cat-personal);
  font-family: "DM Mono", monospace;
  min-height: 1.2em;
  text-align: center;
}

.auth-submit {
  background: var(--text);
  color: var(--bg);
  border: none;
  border-radius: 8px;
  padding: 0.7rem;
  font-family: "DM Sans", sans-serif;
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: opacity 0.15s;
  width: 100%;
}
.auth-submit:hover {
  opacity: 0.88;
}
.auth-submit:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ── App ── */
#app {
  flex: 1;
  display: flex;
  flex-direction: column;
}
#app.hidden {
  display: none;
}

/* ── Header ── */
header {
  padding: 1.5rem 2rem 1rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}
.brand {
  font-family: "Playfair Display", serif;
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}
.brand span {
  color: var(--today-ring);
}

.header-right {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.user-badge {
  font-family: "DM Mono", monospace;
  font-size: 0.7rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.07em;
  border: 1px solid var(--border);
  padding: 0.25rem 0.6rem;
  border-radius: 20px;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}
.user-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cat-tarea);
  display: inline-block;
}

.sync-indicator {
  font-family: "DM Mono", monospace;
  font-size: 0.65rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  opacity: 0;
  transition: opacity 0.3s;
}
.sync-indicator.visible {
  opacity: 1;
}
.sync-indicator.error {
  color: var(--cat-personal);
}

.nav-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.nav-btn {
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text);
  width: 2rem;
  height: 2rem;
  border-radius: 6px;
  cursor: pointer;
  font-size: 1rem;
  display: grid;
  place-items: center;
  transition:
    background 0.15s,
    border-color 0.15s;
}
.nav-btn:hover {
  background: var(--surface);
  border-color: var(--muted);
}
#month-label {
  font-family: "Playfair Display", serif;
  font-size: 1.2rem;
  font-weight: 600;
  min-width: 180px;
  text-align: center;
  letter-spacing: -0.01em;
}
.today-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 0.3rem 0.75rem;
  border-radius: 6px;
  cursor: pointer;
  font-family: "DM Mono", monospace;
  font-size: 0.72rem;
  letter-spacing: 0.05em;
  transition: all 0.15s;
}
.today-btn:hover {
  color: var(--text);
  border-color: var(--muted);
}

.logout-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 0.3rem 0.75rem;
  border-radius: 6px;
  cursor: pointer;
  font-family: "DM Mono", monospace;
  font-size: 0.72rem;
  letter-spacing: 0.05em;
  transition: all 0.15s;
}
.logout-btn:hover {
  color: var(--cat-personal);
  border-color: var(--cat-personal);
}

/* ── Legend ── */
.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  padding: 0.75rem 2rem;
  border-bottom: 1px solid var(--border);
  align-items: center;
}
.legend-label {
  font-size: 0.72rem;
  color: var(--muted);
  font-family: "DM Mono", monospace;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-right: 0.25rem;
}
.chip {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.75rem;
  color: var(--text);
  opacity: 0.85;
  cursor: pointer;
  padding: 0.2rem 0.5rem;
  border-radius: 20px;
  border: 1px solid transparent;
  transition: opacity 0.15s;
  user-select: none;
}
.chip:hover {
  opacity: 1;
}
.chip.off {
  opacity: 0.3;
}
.chip-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}

/* ── Calendar ── */
main {
  flex: 1;
  padding: 1.25rem 2rem 2rem;
}

.weekdays {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 4px;
  margin-bottom: 4px;
}
.weekday {
  text-align: center;
  font-family: "DM Mono", monospace;
  font-size: 0.68rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 0.4rem 0;
}
#calendar-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 4px;
}

.day-cell {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  min-height: 110px;
  padding: 0.5rem 0.55rem 0.55rem;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  transition:
    border-color 0.15s,
    background 0.15s;
  position: relative;
  overflow: hidden;
}
.day-cell:hover {
  border-color: var(--muted);
  background: var(--surface2);
}
.day-cell.other-month {
  opacity: 0.35;
}
.day-cell.today {
  border-color: var(--today-ring);
  box-shadow: 0 0 0 1px var(--today-ring) inset;
}
.day-cell.today .day-num {
  color: var(--today-ring);
}

.day-num {
  font-family: "DM Mono", monospace;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--muted);
  line-height: 1;
}
.note-pills {
  display: flex;
  flex-direction: column;
  gap: 2px;
  flex: 1;
}
.note-pill {
  font-size: 0.68rem;
  line-height: 1.3;
  padding: 2px 6px;
  border-radius: 4px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  font-family: "DM Sans", sans-serif;
  font-weight: 400;
  cursor: pointer;
  transition: filter 0.1s;
}
.note-pill:hover {
  filter: brightness(1.25);
}
.note-pill[data-cat="tarea"] {
  background: var(--cat-tarea-bg);
  color: var(--cat-tarea);
  border-left: 2px solid var(--cat-tarea);
}
.note-pill[data-cat="parcial"] {
  background: var(--cat-parcial-bg);
  color: var(--cat-parcial);
  border-left: 2px solid var(--cat-parcial);
}
.note-pill[data-cat="ccna"] {
  background: var(--cat-ccna-bg);
  color: var(--cat-ccna);
  border-left: 2px solid var(--cat-ccna);
}
.note-pill[data-cat="proyecto"] {
  background: var(--cat-proyecto-bg);
  color: var(--cat-proyecto);
  border-left: 2px solid var(--cat-proyecto);
}
.note-pill[data-cat="personal"] {
  background: var(--cat-personal-bg);
  color: var(--cat-personal);
  border-left: 2px solid var(--cat-personal);
}
.more-notes {
  font-size: 0.63rem;
  color: var(--muted);
  font-family: "DM Mono", monospace;
  align-self: flex-start;
  margin-top: 1px;
}

/* ── Modal ── */
.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(4px);
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s;
}
.overlay.open {
  opacity: 1;
  pointer-events: all;
}
.modal {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  width: 100%;
  max-width: 460px;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  transform: translateY(12px) scale(0.97);
  transition: transform 0.2s;
  overflow: hidden;
}
.overlay.open .modal {
  transform: translateY(0) scale(1);
}
.modal-header {
  padding: 1.2rem 1.4rem 0.9rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
}
.modal-date {
  font-family: "Playfair Display", serif;
  font-size: 1.15rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}
.modal-close {
  background: none;
  border: none;
  color: var(--muted);
  font-size: 1.3rem;
  cursor: pointer;
  line-height: 1;
  transition: color 0.15s;
  padding: 0 0.2rem;
}
.modal-close:hover {
  color: var(--text);
}
.modal-body {
  padding: 1rem 1.4rem;
  overflow-y: auto;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.form-label {
  font-size: 0.72rem;
  color: var(--muted);
  font-family: "DM Mono", monospace;
  text-transform: uppercase;
  letter-spacing: 0.07em;
}
.form-input,
.form-textarea {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 7px;
  color: var(--text);
  font-family: "DM Sans", sans-serif;
  font-size: 0.88rem;
  padding: 0.55rem 0.75rem;
  outline: none;
  transition: border-color 0.15s;
  width: 100%;
}
.form-input:focus,
.form-textarea:focus {
  border-color: var(--muted);
}
.form-textarea {
  resize: vertical;
  min-height: 70px;
  line-height: 1.5;
}

.cat-preview {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-top: 0.1rem;
}
.cat-opt {
  padding: 0.3rem 0.75rem;
  border-radius: 20px;
  font-size: 0.76rem;
  cursor: pointer;
  border: 1.5px solid transparent;
  transition:
    opacity 0.15s,
    border-color 0.15s;
  opacity: 0.55;
}
.cat-opt.active {
  opacity: 1;
}
.cat-opt[data-c="tarea"] {
  background: var(--cat-tarea-bg);
  color: var(--cat-tarea);
  border-color: var(--cat-tarea);
}
.cat-opt[data-c="parcial"] {
  background: var(--cat-parcial-bg);
  color: var(--cat-parcial);
  border-color: var(--cat-parcial);
}
.cat-opt[data-c="ccna"] {
  background: var(--cat-ccna-bg);
  color: var(--cat-ccna);
  border-color: var(--cat-ccna);
}
.cat-opt[data-c="proyecto"] {
  background: var(--cat-proyecto-bg);
  color: var(--cat-proyecto);
  border-color: var(--cat-proyecto);
}
.cat-opt[data-c="personal"] {
  background: var(--cat-personal-bg);
  color: var(--cat-personal);
  border-color: var(--cat-personal);
}

.add-btn {
  background: var(--text);
  color: var(--bg);
  border: none;
  border-radius: 7px;
  padding: 0.6rem 1rem;
  font-family: "DM Sans", sans-serif;
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: opacity 0.15s;
  align-self: flex-end;
}
.add-btn:hover {
  opacity: 0.88;
}
.add-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.notes-list {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.notes-divider {
  font-size: 0.7rem;
  color: var(--muted);
  font-family: "DM Mono", monospace;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding-bottom: 0.3rem;
  border-bottom: 1px solid var(--border);
}
.note-item {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.6rem 0.85rem;
  display: flex;
  align-items: flex-start;
  gap: 0.65rem;
}
.note-item-bar {
  width: 3px;
  border-radius: 2px;
  flex-shrink: 0;
  align-self: stretch;
  margin-top: 1px;
}
.note-item-bar[data-cat="tarea"] {
  background: var(--cat-tarea);
}
.note-item-bar[data-cat="parcial"] {
  background: var(--cat-parcial);
}
.note-item-bar[data-cat="ccna"] {
  background: var(--cat-ccna);
}
.note-item-bar[data-cat="proyecto"] {
  background: var(--cat-proyecto);
}
.note-item-bar[data-cat="personal"] {
  background: var(--cat-personal);
}
.note-item-body {
  flex: 1;
  min-width: 0;
}
.note-item-title {
  font-size: 0.85rem;
  color: var(--text);
  line-height: 1.3;
  word-break: break-word;
}
.note-item-desc {
  font-size: 0.75rem;
  color: var(--muted);
  margin-top: 0.2rem;
  line-height: 1.4;
  word-break: break-word;
}
.note-item-meta {
  font-size: 0.65rem;
  color: var(--muted);
  font-family: "DM Mono", monospace;
  margin-top: 0.35rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.note-delete {
  background: none;
  border: none;
  color: var(--muted);
  font-size: 0.95rem;
  cursor: pointer;
  line-height: 1;
  padding: 0;
  flex-shrink: 0;
  transition: color 0.15s;
}
.note-delete:hover {
  color: #fb7185;
}
.empty-day {
  text-align: center;
  color: var(--muted);
  font-size: 0.82rem;
  padding: 0.75rem 0 0.25rem;
  font-family: "DM Mono", monospace;
}

::-webkit-scrollbar {
  width: 5px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 10px;
}

@media (max-width: 680px) {
  header {
    padding: 1rem 1rem 0.8rem;
  }
  main {
    padding: 0.75rem 1rem 1.5rem;
  }
  .legend {
    padding: 0.6rem 1rem;
  }
  .day-cell {
    min-height: 72px;
    padding: 0.35rem 0.35rem 0.4rem;
  }
  .note-pill {
    font-size: 0.6rem;
  }
  #month-label {
    font-size: 1rem;
    min-width: 150px;
  }
}