:root {
  --bg: #f5f7fa;
  --card-bg: #ffffff;
  --text: #1b1f24;
  --muted: #5b6572;
  --border: #e1e5ea;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --error-bg: #fdecec;
  --error-text: #9b1c1c;
  --error-border: #f3b4b4;
  --info-bg: #eaf3fd;
  --info-text: #17497e;
  --info-border: #bcdaf7;
  --high-color: #e0592a;
  --low-color: #2563eb;
  --radius: 10px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 4px 12px rgba(0, 0, 0, 0.04);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14171c;
    --card-bg: #1c2027;
    --text: #eef1f4;
    --muted: #9aa4b1;
    --border: #2c313a;
    --accent: #4d8dff;
    --accent-hover: #6ba0ff;
    --error-bg: #3a1e1e;
    --error-text: #ffb4b4;
    --error-border: #6b2c2c;
    --info-bg: #16283b;
    --info-text: #a9d0fb;
    --info-border: #2c4b6e;
    --high-color: #ff8a5c;
    --low-color: #6ba0ff;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.4), 0 4px 16px rgba(0, 0, 0, 0.3);
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

.app {
  max-width: 800px;
  margin: 0 auto;
  padding: 32px 20px 60px;
}

header h1 {
  font-size: 1.6rem;
  margin: 0 0 4px;
}

.subtitle {
  margin: 0 0 24px;
  color: var(--muted);
  font-size: 0.95rem;
}

.mode-toggle {
  display: inline-flex;
  gap: 4px;
  padding: 4px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 16px;
}

.mode-btn {
  border: none;
  background: transparent;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 600;
  padding: 8px 16px;
  border-radius: calc(var(--radius) - 4px);
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease;
}

.mode-btn:hover {
  color: var(--text);
}

.mode-btn.active {
  background: var(--accent);
  color: #fff;
}

.zip-form {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.zip-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.historical-controls {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 14px 16px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.historical-controls[hidden] {
  display: none;
}

.optimal-weather-row {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.optimal-weather-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text);
}

.optimal-weather-inputs {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.optimal-weather-inputs label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.82rem;
  color: var(--muted);
}

.optimal-weather-inputs input[type="number"] {
  width: 68px;
  padding: 8px 10px;
  font-size: 0.95rem;
  border: 1px solid var(--border);
  border-radius: calc(var(--radius) - 2px);
  background: var(--bg);
  color: var(--text);
}

.optimal-weather-inputs input[type="number"]:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

.optimal-weather-tolerance-note {
  font-size: 0.78rem;
  color: var(--muted);
  font-style: italic;
}

.preset-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.preset-btn {
  padding: 7px 14px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 999px;
  cursor: pointer;
  transition: background 0.15s ease, border-color 0.15s ease;
}

.preset-btn:hover {
  border-color: var(--accent);
}

.preset-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.date-range-row {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.date-range-row label {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 0.82rem;
  color: var(--muted);
  flex: 1 1 160px;
}

.date-range-row input[type="date"] {
  padding: 10px 12px;
  font-size: 0.95rem;
  border: 1px solid var(--border);
  border-radius: calc(var(--radius) - 2px);
  background: var(--bg);
  color: var(--text);
}

.date-range-row input[type="date"]:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

#zip-input {
  flex: 1 1 220px;
  min-width: 0;
  padding: 12px 14px;
  font-size: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--card-bg);
  color: var(--text);
}

#zip-input:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

#submit-btn {
  padding: 12px 22px;
  font-size: 1rem;
  font-weight: 600;
  color: #fff;
  background: var(--accent);
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  transition: background 0.15s ease;
  flex: 0 0 auto;
}

#submit-btn:hover {
  background: var(--accent-hover);
}

#submit-btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
}

.status {
  margin-top: 16px;
  min-height: 0;
}

.status:empty {
  margin-top: 0;
}

.status .message {
  padding: 12px 16px;
  border-radius: var(--radius);
  font-size: 0.92rem;
}

.status .message.loading {
  background: var(--card-bg);
  border: 1px solid var(--border);
  color: var(--muted);
  display: flex;
  align-items: center;
  gap: 10px;
}

.status .message.error {
  background: var(--error-bg);
  border: 1px solid var(--error-border);
  color: var(--error-text);
}

.spinner {
  width: 16px;
  height: 16px;
  border: 2px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  flex: 0 0 auto;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.chart-card {
  margin-top: 20px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
  display: none;
}

.chart-card.visible {
  display: block;
}

.optimal-weather-card {
  margin-top: 16px;
}

.optimal-weather-summary {
  font-size: 0.95rem;
  line-height: 1.5;
  margin-bottom: 14px;
}

.optimal-weather-month {
  margin-bottom: 14px;
}

.optimal-weather-month:last-child {
  margin-bottom: 0;
}

.optimal-weather-month-heading {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 4px;
}

.optimal-weather-ranges {
  font-size: 0.85rem;
  color: var(--muted);
  line-height: 1.6;
}

.optimal-weather-note {
  font-size: 0.8rem;
  color: var(--muted);
  margin-top: 12px;
  font-style: italic;
}

.optimal-weather-empty {
  font-size: 0.92rem;
  color: var(--muted);
  line-height: 1.5;
}

.optimal-weather-error {
  font-size: 0.92rem;
  color: var(--error-text);
  background: var(--error-bg);
  border: 1px solid var(--error-border);
  border-radius: var(--radius);
  padding: 10px 14px;
}

.location-label {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--text);
}

.sprinkler-alert {
  background: var(--info-bg);
  border: 1px solid var(--info-border);
  color: var(--info-text);
  border-radius: var(--radius);
  padding: 12px 16px;
  margin-bottom: 16px;
  font-size: 0.92rem;
  line-height: 1.4;
}

.sprinkler-alert[hidden] {
  display: none;
}

.precip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}

.precip-row[hidden] {
  display: none;
}

.precip-chip {
  flex: 1 1 0;
  min-width: 64px;
  text-align: center;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 8px 6px;
}

.precip-date {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--muted);
  margin-bottom: 4px;
}

.precip-value {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--muted);
}

.precip-value.notable {
  color: var(--info-text);
}

.chart-wrap {
  position: relative;
  height: 380px;
}

@media (max-width: 480px) {
  .chart-wrap {
    height: min(75vh, 700px);
    min-height: 420px;
  }

  #submit-btn {
    width: 100%;
  }

  .zip-form {
    flex-direction: column;
  }
}