/* CSS Variables for theming */
:root {
  --primary-color: #4f46e5;
  --bg-color: #ffffff;
  --surface-color: #f9fafb;
  --text-primary: #111827;
  --text-secondary: #6b7280;
  --border-color: #e5e7eb;
  --highlight-color: #fef3c7;
  --today-color: #fbbf24;
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

/* Dark mode */
@media (prefers-color-scheme: dark) {
  :root {
    --primary-color: #4338ca;
    --bg-color: #111827;
    --surface-color: #1f2937;
    --text-primary: #f9fafb;
    --text-secondary: #9ca3af;
    --border-color: #374151;
    --highlight-color: #78350f;
    --today-color: #f59e0b;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4);
  }
}

/* Reset and base styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* Header */
header {
  padding: 1rem;
}

header h1 {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 400;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.ad-range {
  font-size: clamp(0.875rem, 2vw, 1rem);
  color: var(--text-secondary);
  font-weight: 400;
}

nav {
  margin-bottom: 1rem;
}

.back-link {
  display: inline-block;
  color: var(--primary-color);
  text-decoration: none;
  font-size: 0.875rem;
  padding: 0.5rem 1rem;
  border-radius: 0.375rem;
  transition: background-color 0.2s;
}

.back-link:hover {
  background-color: var(--surface-color);
}

/* Footer */
footer {
  text-align: center;
  padding: 2rem 1rem;
  color: var(--text-secondary);
  font-size: 0.875rem;
  border-top: 1px solid var(--border-color);
  margin-top: 2rem;
}

footer a {
  color: var(--primary-color);
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}

/* Year view (Homepage) */
.year-view {
  padding: 1rem;
  height: calc(100vh - 200px);
  display: flex;
  align-items: center;
  justify-content: center;
}

.months-grid {
  display: grid;
  gap: 1rem;
  width: 100%;
  max-width: 1400px;
  height: 100%;
  padding: 1rem;
}

/* Responsive grid layouts */
/* Mobile: 3 columns x 4 rows */
@media (max-width: 768px) {
  .months-grid {
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(4, 1fr);
  }
}

/* Desktop: 4 columns x 3 rows */
@media (min-width: 769px) {
  .months-grid {
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(3, 1fr);
  }
}

/* Month card */
.month-card {
  border-radius: 0.5rem;
  padding: 0.75rem;
  text-decoration: none;
  color: var(--text-primary);
  transition: all 0.2s;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  cursor: pointer;
}

.month-card:hover {
  box-shadow: var(--shadow-lg);
  background-color: var(--surface-color);
  transform: translateY(-2px);
  border-color: var(--primary-color);
}

.month-header {
  margin-bottom: 0.5rem;
}

.month-header h3 {
  font-size: clamp(0.875rem, 1.5vw, 1.25rem);
  font-weight: 700;
  color: var(--primary-color);
}

/* Mini calendar in month card */
.mini-calendar {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.weekdays {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 0.125rem;
  margin-bottom: 0.25rem;
}

.weekday {
  font-size: clamp(0.625rem, 1vw, 0.75rem);
  font-weight: 600;
  color: var(--text-secondary);
  text-align: center;
  padding: 0.125rem;
}

.days {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 0.125rem;
  flex: 1;
}

.day {
  aspect-ratio: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: clamp(0.625rem, 1vw, 0.875rem);
  border-radius: 0.25rem;
  transition: background-color 0.2s;
}

.day.empty {
  visibility: hidden;
}

.day.today {
  background-color: var(--today-color);
  color: var(--bg-color);
  font-weight: 700;
}

/* Month view (Full month page) */
.month-view {
  display: flex;
  flex-direction: column;
  height: calc(100vh - 120px);
  padding: 0;
  margin: 0;
}

.calendar-full {
  display: flex;
  flex-direction: column;
  flex: 1;
  background-color: var(--bg-color);
  border: 1px solid var(--border-color);
}

.weekday-header {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  border-bottom: 1px solid var(--border-color);
  background-color: var(--surface-color);
}

.weekday-label {
  font-weight: 600;
  font-size: clamp(0.75rem, 1.5vw, 0.875rem);
  text-align: center;
  color: var(--text-secondary);
  padding: 0.75rem 0.5rem;
  border-right: 1px solid var(--border-color);
}

.weekday-label:last-child {
  border-right: none;
}

/* Show full names by default, hide short names */
.weekday-label .short {
  display: none;
}

.weekday-label .full {
  display: inline;
}

.calendar-grid {
  display: flex;
  flex-direction: column;
  flex: 1;
}

.calendar-week {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  flex: 1;
  border-bottom: 1px solid var(--border-color);
}

.calendar-week:last-child {
  border-bottom: none;
}

.calendar-day {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  border-right: 1px solid var(--border-color);
  background-color: var(--bg-color);
  transition: background-color 0.2s;
  padding: 0.5rem;
  min-height: 80px;
}

.calendar-day:last-child {
  border-right: none;
}

.calendar-day:not(.empty):hover {
  background-color: var(--surface-color);
}

.calendar-day.empty {
  background-color: var(--surface-color);
}

.bs-day {
  font-size: clamp(1.5rem, 4vw, 2.5rem);
  font-weight: 300;
  color: var(--text-primary);
}

.ad-day {
  position: absolute;
  bottom: 0.5rem;
  right: 0.5rem;
  font-size: clamp(0.625rem, 1.5vw, 0.75rem);
  color: var(--text-secondary);
  font-weight: 400;
}

.calendar-day.today {
  background-color: var(--highlight-color);
}

.calendar-day.today .bs-day {
  color: var(--today-color);
  font-weight: 600;
}

.calendar-day.today .ad-day {
  color: var(--today-color);
  font-weight: 500;
}

/* Dynamic pages */
.dynamic-page {
  max-width: 600px;
  margin: 2rem auto;
  padding: 1rem;
}

.preferences-content,
.subscribe-content {
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: 0.5rem;
  padding: 2rem;
  box-shadow: var(--shadow-lg);
}

.preferences-content h2,
.subscribe-content h2 {
  margin-bottom: 1rem;
  color: var(--primary-color);
}

.preference-item {
  margin: 1.5rem 0;
}

.preference-item label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
}

.form-group {
  margin: 1.5rem 0;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
}

.form-group input[type="email"],
.form-group input[type="text"] {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--border-color);
  border-radius: 0.375rem;
  background-color: var(--bg-color);
  color: var(--text-primary);
  font-size: 1rem;
}

input[type="checkbox"] {
  width: 1.25rem;
  height: 1.25rem;
  cursor: pointer;
}

button {
  background-color: var(--primary-color);
  color: white;
  border: none;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  font-weight: 500;
  border-radius: 0.375rem;
  cursor: pointer;
  transition: background-color 0.2s;
  margin-top: 1rem;
}

button:hover {
  background-color: var(--primary-dark);
}

button:active {
  transform: translateY(1px);
}

#ical-result {
  margin-top: 1.5rem;
  padding: 1rem;
  background-color: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: 0.375rem;
}

#ical-result h3 {
  margin-bottom: 0.5rem;
  font-size: 1rem;
}

#ical-link {
  width: 100%;
  padding: 0.75rem;
  margin-bottom: 0.5rem;
  font-family: monospace;
  font-size: 0.875rem;
}

/* Responsive adjustments */
@media (max-width: 640px) {
  header {
    padding: 1rem 0.5rem 0.5rem;
  }

  .year-view {
    height: calc(100vh - 150px);
    padding: 0.5rem;
  }

  .months-grid {
    gap: 0.5rem;
    padding: 0.5rem;
  }

  .month-card {
    padding: 0.5rem;
  }

  .month-view {
    height: calc(100vh - 100px);
  }

  /* Show short day names on mobile, hide full names */
  .weekday-label .full {
    display: none;
  }

  .weekday-label .short {
    display: inline;
  }

  .weekday-label {
    font-size: 0.75rem;
    padding: 0.5rem 0.25rem;
  }

  .calendar-day {
    min-height: 60px;
    padding: 0.25rem;
  }

  .bs-day {
    font-size: 1.25rem;
  }

  .ad-day {
    font-size: 0.625rem;
    bottom: 0.25rem;
    right: 0.25rem;
  }

  .dynamic-page {
    padding: 0.5rem;
  }

  .preferences-content,
  .subscribe-content {
    padding: 1.5rem;
  }
}

/* Print styles */
@media print {
  .back-link,
  footer {
    display: none;
  }

  .calendar-day.today {
    border: 2px solid black !important;
  }
}