:root {
  --bg: #0d0d12;
  --bg-2: #15161c;
  --bg-3: #1c1d25;
  --fg: #e8e9ef;
  --fg-dim: #98a1b3;
  --fg-dimmer: #6a7388;
  --accent: #f3e8b8;
  --accent-2: #6db8ff;
  --border: #2a2b35;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Hiragino Kaku Gothic ProN",
    "Yu Gothic UI", "Yu Gothic", Meiryo, sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  min-height: 100vh;
}

main {
  max-width: 980px;
  margin: 0 auto;
  padding: 32px 20px 60px;
}

header h1 {
  margin: 0 0 6px;
  font-size: 28px;
  letter-spacing: -0.01em;
}
header h1 .sub {
  font-size: 18px;
  color: var(--fg-dim);
  font-weight: 400;
  margin-left: 8px;
}
header .lede {
  margin: 0 0 28px;
  color: var(--fg-dim);
  line-height: 1.6;
  max-width: 60ch;
}

/* ─────── hero ─────── */

.hero {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 28px;
  align-items: center;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  margin-bottom: 24px;
}

.hero-svg {
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-svg svg {
  width: 220px;
  height: 220px;
  filter: drop-shadow(0 6px 24px rgba(243, 232, 184, 0.08));
}

.hero-info {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.phase-name {
  font-size: 26px;
  font-weight: 600;
  letter-spacing: 0.01em;
}
.phase-emoji {
  font-size: 24px;
  color: var(--fg-dim);
}

.info {
  border-collapse: collapse;
  width: 100%;
  margin-top: 6px;
}
.info th, .info td {
  text-align: left;
  padding: 6px 0;
  border-bottom: 1px solid var(--border);
  font-size: 14px;
}
.info th {
  color: var(--fg-dim);
  font-weight: 500;
  width: 7em;
}
.info td {
  color: var(--fg);
  font-variant-numeric: tabular-nums;
}

.upcoming {
  display: flex;
  gap: 24px;
  margin-top: 8px;
  font-size: 13px;
}
.upcoming .label {
  display: block;
  color: var(--fg-dim);
  font-size: 11px;
  margin-bottom: 2px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

/* ─────── controls ─────── */

.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  margin-bottom: 24px;
}

.controls label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 6px 10px;
  font-size: 13px;
  color: var(--fg-dim);
}

.controls input[type="datetime-local"] {
  background: transparent;
  border: none;
  color: var(--fg);
  font-family: inherit;
  font-size: 14px;
  font-variant-numeric: tabular-nums;
  outline: none;
}

.controls button {
  background: var(--bg-2);
  color: var(--fg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 14px;
  font-family: inherit;
  font-size: 13px;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
}
.controls button:hover {
  background: var(--bg-3);
  border-color: var(--accent-2);
}

/* ─────── calendar ─────── */

.calendar {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 24px;
}

.calendar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}
.calendar-header h2 {
  margin: 0;
  font-size: 18px;
  font-weight: 500;
}
.calendar-header button {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--fg);
  border-radius: 6px;
  width: 32px;
  height: 32px;
  font-size: 18px;
  cursor: pointer;
}
.calendar-header button:hover {
  border-color: var(--accent-2);
}

.calendar-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 4px;
}

.day-cell {
  background: var(--bg-3);
  border-radius: 6px;
  padding: 8px 6px;
  text-align: center;
  cursor: pointer;
  border: 1px solid transparent;
  transition: border-color 0.1s;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  font-size: 12px;
  color: var(--fg-dim);
}
.day-cell:hover {
  border-color: var(--accent-2);
}
.day-cell.in-month {
  color: var(--fg);
}
.day-cell.adjacent {
  opacity: 0.4;
}
.day-cell.selected {
  border-color: var(--accent);
  background: #1f2030;
}

.day-cell .day-num {
  font-weight: 500;
  font-variant-numeric: tabular-nums;
}

.day-cell svg {
  width: 30px;
  height: 30px;
}

/* ─────── explainer ─────── */

.explainer {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px 24px;
  margin-bottom: 24px;
}
.explainer h2 {
  margin: 0 0 12px;
  font-size: 15px;
  color: var(--fg-dim);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.explainer ul {
  margin: 0;
  padding-left: 18px;
  line-height: 1.8;
  color: var(--fg-dim);
}
.explainer code {
  background: var(--bg-3);
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--fg);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 13px;
}

footer {
  margin-top: 32px;
  text-align: center;
  color: var(--fg-dimmer);
  font-size: 12px;
}
footer a {
  color: var(--fg-dim);
}

@media (max-width: 640px) {
  .hero {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero-svg { justify-content: center; }
  .info th { width: 5em; }
  .controls { font-size: 12px; }
  .day-cell svg { width: 24px; height: 24px; }
}