* {
  box-sizing: border-box;
}

:root {
  --bg: #f5f7fb;
  --surface: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --border: #d9e0ea;
  --shadow: 0 10px 30px rgba(17, 24, 39, 0.08);
  --available: #dff6df;
  --available-border: #9dd89d;
  --blocked: #f9d6d6;
  --blocked-border: #e68b8b;
  --primary: #111827;
  --primary-contrast: #ffffff;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: linear-gradient(180deg, #f7f9fc 0%, #eef3f9 100%);
  color: var(--text);
}

.page {
  max-width: 1440px;
  margin: 0 auto;
  padding: 24px;
}

.topbar {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 20px;
}

.topbar h1,
.login-box h1 {
  margin: 0 0 8px;
  font-size: clamp(28px, 4vw, 40px);
}

.subtitle {
  margin: 0;
  color: var(--muted);
}

.topbar-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.admin-link,
button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 0;
  border-radius: 12px;
  background: var(--bg);
  color: var(--primary);
  text-decoration: none;
  padding: 12px 16px;
  cursor: pointer;
  font-size: 15px;
  font-weight: 600;
  transition: transform 0.15s ease, opacity 0.15s ease, box-shadow 0.15s ease;
  box-shadow: 0 6px 14px rgba(17, 24, 39, 0.12);
}

.admin-link.secondary {
  background: #e9eef6;
  color: var(--text);
}

.admin-link:hover,
button:hover {
  transform: translateY(-1px);
}

.legend {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  background: rgba(255, 255, 255, 0.65);
  border: 1px solid rgba(217, 224, 234, 0.9);
  border-radius: 14px;
  padding: 14px 16px;
  margin-bottom: 18px;
  backdrop-filter: blur(8px);
}

.legend-item {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
}

.legend-box {
  width: 18px;
  height: 18px;
  border-radius: 6px;
  border: 1px solid transparent;
}

.legend-box.available {
  background: var(--available);
  border-color: var(--available-border);
}

.legend-box.blocked {
  background: var(--blocked);
  border-color: var(--blocked-border);
}

.hint {
  margin: 0 0 20px;
  color: var(--muted);
}

.controls,
.view-switch {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 18px;
  flex-wrap: wrap;
}

.controls h2 {
  margin: 0;
  min-width: 220px;
  font-size: clamp(22px, 3vw, 30px);
}

button.active {
  outline: 3px solid #bfd2ff;
}

#calendarContainer {
  display: grid;
  gap: 24px;
}

.year-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 20px;
}

.month-card {
  background: var(--surface);
  border-radius: 20px;
  padding: 18px;
  box-shadow: var(--shadow);
  border: 1px solid rgba(217, 224, 234, 0.8);
}

.month-title {
  margin: 0 0 16px;
  font-size: 20px;
}

.month-grid {
  display: grid;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  gap: 8px;
}

.weekday {
  text-align: center;
  font-size: 13px;
  font-weight: 700;
  color: var(--muted);
  padding: 8px 0;
}

.day {
  min-height: 54px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--available);
  border: 1px solid var(--available-border);
  font-weight: 700;
  font-size: 14px;
  user-select: none;
  position: relative;
}

.day.blocked {
  background: var(--blocked);
  border-color: var(--blocked-border);
}

.day.today {
  box-shadow: inset 0 0 0 2px #4473d9;
}

.day.empty {
  background: transparent;
  border-color: transparent;
}

.day.admin {
  cursor: pointer;
}

.day.admin:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 12px rgba(17, 24, 39, 0.1);
}

.day.disabled {
  opacity: 0.55;
}

.login-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.login-box {
  width: 100%;
  max-width: 420px;
  background: var(--surface);
  padding: 28px;
  border-radius: 22px;
  box-shadow: var(--shadow);
  border: 1px solid rgba(217, 224, 234, 0.8);
}

.login-box form {
  display: grid;
  gap: 12px;
  margin-top: 20px;
}

.login-box label {
  font-weight: 700;
}

.login-box input {
  width: 100%;
  padding: 14px 16px;
  border-radius: 12px;
  border: 1px solid var(--border);
  font-size: 16px;
}

.error {
  margin: 16px 0 0;
  color: #a00000;
  font-weight: 700;
}

@media (max-width: 760px) {
  .page {
    padding: 16px;
  }

  .topbar {
    flex-direction: column;
  }

  .controls {
    align-items: stretch;
  }

  .controls h2 {
    min-width: 0;
    width: 100%;
  }

  .month-card {
    padding: 14px;
  }

  .day {
    min-height: 42px;
    font-size: 13px;
  }
}