html,
html[data-theme="dark"] {
  --bg: #000000;
  --bg-secondary: #1c1c1e;
  --bg-tertiary: #2c2c2e;
  --bg-input: #1c1c1e;
  --fill-secondary: rgba(120, 120, 128, 0.32);
  --fill-primary: rgba(120, 120, 128, 0.36);
  --separator: rgba(84, 84, 88, 0.65);
  --text: #ffffff;
  --text-secondary: rgba(235, 235, 245, 0.65);
  --text-tertiary: rgba(235, 235, 245, 0.35);
  --accent: #d4a017;
  --accent-text: #111111;
  --danger: #ff453a;
  --radius-card: 16px;
  --radius-input: 10px;
  --radius-button: 14px;
  --radius-segment: 9px;
  color-scheme: dark;
}

html[data-theme="light"] {
  --bg: #f2f2f7;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f2f2f7;
  --bg-input: #ffffff;
  --fill-secondary: rgba(120, 120, 128, 0.16);
  --fill-primary: rgba(120, 120, 128, 0.2);
  --separator: rgba(60, 60, 67, 0.29);
  --text: #000000;
  --text-secondary: rgba(60, 60, 67, 0.65);
  --text-tertiary: rgba(60, 60, 67, 0.35);
  --accent: #b8860b;
  --accent-text: #ffffff;
  --danger: #ff3b30;
  color-scheme: light;
}

* {
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
}

html {
  -webkit-text-size-adjust: 100%;
  background: var(--bg);
  color: var(--text);
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display",
    "Helvetica Neue", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 17px;
  line-height: 1.4;
  letter-spacing: -0.2px;
  transition: background 0.25s ease, color 0.25s ease;
  min-height: 100vh;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  padding: 12px 16px 8px;
  padding-top: max(12px, env(safe-area-inset-top));
  background: var(--bg);
  color: var(--text);
  border-bottom: 0.5px solid var(--separator);
}
.header-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.site-header h1 {
  margin: 0;
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.6px;
  color: var(--text);
}
.subtitle {
  margin: 4px 0 0;
  font-size: 12px;
  color: var(--text-secondary);
  letter-spacing: -0.1px;
  line-height: 1.3;
}
.theme-btn {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--fill-secondary);
  color: var(--text);
  border: none;
  font-size: 18px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.15s ease, background 0.2s ease;
}
.theme-btn:active {
  transform: scale(0.92);
  background: var(--fill-primary);
}

.layout {
  display: grid;
  grid-template-columns: 380px 1fr;
  gap: 20px;
  max-width: 1280px;
  margin: 20px auto 40px;
  padding: 0 16px;
}
@media (max-width: 900px) {
  .layout {
    grid-template-columns: 1fr;
    margin: 12px 0 calc(24px + env(safe-area-inset-bottom));
    padding: 0 12px;
    gap: 12px;
  }
}

.form-panel,
.chart-panel {
  background: var(--bg-secondary);
  color: var(--text);
  border-radius: var(--radius-card);
  padding: 16px;
}
@media (max-width: 900px) {
  .form-panel,
  .chart-panel {
    padding: 14px;
    border-radius: 14px;
  }
}

h2 {
  margin: 0 0 12px;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.3px;
  color: var(--text);
}
h3 {
  margin: 20px 0 8px;
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-secondary);
}
h3:first-of-type { margin-top: 8px; }

.mode-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  padding: 4px;
  background: var(--fill-secondary);
  border-radius: var(--radius-segment);
  margin-bottom: 16px;
}
.tab {
  flex: 1 1 auto;
  padding: 7px 12px;
  border: none;
  border-radius: 7px;
  background: transparent;
  color: var(--text);
  font-family: inherit;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: -0.2px;
  cursor: pointer;
  white-space: nowrap;
  text-align: center;
  min-width: 0;
  transition: background 0.2s ease, box-shadow 0.2s ease, transform 0.1s ease;
}
.tab:active { transform: scale(0.96); }
.tab.active {
  background: var(--bg-secondary);
  color: var(--text);
  box-shadow: 0 3px 8px rgba(0, 0, 0, 0.12), 0 1px 2px rgba(0, 0, 0, 0.08);
  font-weight: 600;
}

label {
  display: block;
  margin-bottom: 12px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  letter-spacing: 0.1px;
}
input[type="date"],
input[type="time"],
input[type="number"],
input[type="text"],
select {
  display: block;
  width: 100%;
  margin-top: 6px;
  padding: 13px 14px;
  background: var(--bg-input);
  border: none;
  border-radius: var(--radius-input);
  color: var(--text);
  font-family: inherit;
  font-size: 17px;
  font-weight: 400;
  letter-spacing: -0.2px;
  -webkit-appearance: none;
  appearance: none;
  transition: box-shadow 0.15s ease;
}
input:focus,
select:focus {
  outline: none;
  box-shadow: 0 0 0 3px rgba(212, 160, 23, 0.35);
}
html[data-theme="light"] input:focus,
html[data-theme="light"] select:focus {
  box-shadow: 0 0 0 3px rgba(184, 134, 11, 0.3);
}
input::placeholder { color: var(--text-tertiary); }
select {
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'><path d='M2 4l4 4 4-4' stroke='%23888' stroke-width='1.5' fill='none' stroke-linecap='round'/></svg>");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 36px;
}
.row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}
.hidden { display: none !important; }
.hint {
  font-size: 12px;
  color: var(--text-secondary);
  margin: -4px 0 12px;
  line-height: 1.4;
}

button[type="submit"] {
  width: 100%;
  padding: 15px 20px;
  background: var(--accent);
  color: var(--accent-text);
  border: none;
  border-radius: var(--radius-button);
  font-family: inherit;
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.3px;
  cursor: pointer;
  margin-top: 8px;
  transition: transform 0.1s ease, opacity 0.2s ease;
  -webkit-user-select: none;
  user-select: none;
}
button[type="submit"]:active { transform: scale(0.98); opacity: 0.9; }
button[type="submit"]:disabled { opacity: 0.5; cursor: wait; }

@media (max-width: 900px) {
  button[type="submit"] {
    position: sticky;
    bottom: max(12px, env(safe-area-inset-bottom));
    z-index: 50;
    box-shadow: 0 6px 24px rgba(0, 0, 0, 0.35);
    margin-top: 16px;
  }
}

.status {
  min-height: 20px;
  margin: 12px 0 0;
  font-size: 13px;
  color: var(--text-secondary);
  letter-spacing: -0.1px;
  line-height: 1.4;
}
.status.error { color: var(--danger); }

.chart-toolbar {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
}
.tool-btn {
  flex: 1;
  padding: 10px 12px;
  background: var(--fill-secondary);
  color: var(--text);
  border: none;
  border-radius: 10px;
  font-family: inherit;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: -0.2px;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.1s ease;
}
.tool-btn:active {
  transform: scale(0.97);
  background: var(--fill-primary);
}

.chart-container {
  min-height: 480px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: 4px;
}
.chart-container svg { max-width: 100%; height: auto; display: block; }
.placeholder { color: var(--text-secondary); font-size: 14px; text-align: center; padding: 40px 16px; }

.interpretation {
  margin-top: 16px;
  padding: 14px;
  background: var(--bg-tertiary);
  color: var(--text);
  border-radius: 12px;
  font-size: 14px;
  line-height: 1.5;
  letter-spacing: -0.1px;
}
.interpretation h3 {
  margin: 0 0 10px;
  font-size: 15px;
  font-weight: 600;
  text-transform: none;
  letter-spacing: -0.3px;
  color: var(--text);
}
.interpretation ul { padding-left: 20px; margin: 0; }
.interpretation li { margin-bottom: 8px; color: var(--text); }

.history-block {
  margin-top: 24px;
  padding-top: 16px;
  border-top: 0.5px solid var(--separator);
}
#history-list {
  list-style: none;
  padding: 0;
  margin: 8px 0 0;
  max-height: 260px;
  overflow-y: auto;
}
#history-list li { margin-bottom: 6px; }
.history-item {
  width: 100%;
  text-align: left;
  padding: 12px 14px;
  background: var(--bg-input);
  color: var(--text);
  border: none;
  border-radius: 10px;
  font-family: inherit;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: -0.2px;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  transition: background 0.15s ease, transform 0.1s ease;
}
.history-item:active {
  transform: scale(0.98);
  background: var(--fill-secondary);
}
.history-date {
  color: var(--text-secondary);
  font-size: 11px;
  font-weight: 400;
  flex-shrink: 0;
}

.json-tools {
  display: flex;
  gap: 8px;
  margin-top: 12px;
}
.json-tools .tool-btn {
  flex: 1;
  padding: 10px 12px;
  font-size: 13px;
}

.site-footer {
  text-align: center;
  padding: 24px 16px;
  padding-bottom: max(24px, calc(env(safe-area-inset-bottom) + 16px));
  font-size: 12px;
  color: var(--text-secondary);
  letter-spacing: -0.1px;
}
.site-footer a { color: var(--accent); text-decoration: none; }
.site-footer a:hover { text-decoration: underline; }

@media (max-width: 480px) {
  body { font-size: 16px; }
  .site-header h1 { font-size: 20px; }
  .form-panel,
  .chart-panel { padding: 12px; border-radius: 12px; }
  .chart-toolbar { gap: 6px; }
  .tool-btn { padding: 9px 10px; font-size: 13px; }
  .chart-container { min-height: 380px; }
  .tab { font-size: 12px; padding: 6px 10px; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
}