:root {
  --bg: #0f1412;
  --card: #1a2420;
  --card-hover: #213029;
  --ink: #eef4ef;
  --muted: #8fa39a;
  --line: #2c3b34;
  --accent: #3ecf8e;
  --accent-ink: #0a1a12;
  --warn: #f0a23a;
  --ring: #2a3a32;
  --shadow: 0 12px 40px rgba(0, 0, 0, 0.35);
  color-scheme: dark;
  font-family: Manrope, system-ui, sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  min-height: 100%;
  background:
    radial-gradient(1200px 600px at 10% -10%, #1a3a2c 0%, transparent 55%),
    radial-gradient(900px 500px at 100% 0%, #2a2414 0%, transparent 45%),
    var(--bg);
  color: var(--ink);
  touch-action: manipulation;
}

body {
  min-height: 100dvh;
  padding:
    env(safe-area-inset-top)
    env(safe-area-inset-right)
    calc(16px + env(safe-area-inset-bottom))
    env(safe-area-inset-left);
}

button, input, select {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  border: 0;
  background: none;
}

#app {
  max-width: 560px;
  margin: 0 auto;
  padding: 16px;
}

.top {
  margin-bottom: 20px;
}

.brand h1 {
  margin: 0;
  font-size: 1.55rem;
  font-weight: 800;
  letter-spacing: -0.04em;
}

.brand p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.panel {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 18px;
  box-shadow: var(--shadow);
}

.panel h2 {
  margin: 0 0 14px;
  font-size: 1.05rem;
  font-weight: 700;
}

.field {
  display: grid;
  gap: 6px;
  margin-bottom: 14px;
}

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

.field input,
.field select {
  width: 100%;
  padding: 12px 14px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: #121a17;
  outline: none;
}

.field input:focus,
.field select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(62, 207, 142, 0.18);
}

.row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

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

.chip {
  padding: 8px 12px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: #121a17;
  color: var(--muted);
  font-size: 0.85rem;
  font-weight: 600;
}

.chip:hover { color: var(--ink); border-color: #3a4f45; }
.chip.active {
  color: var(--accent-ink);
  background: var(--accent);
  border-color: var(--accent);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 48px;
  padding: 0 18px;
  border-radius: 14px;
  font-weight: 700;
  transition: transform 0.12s ease, background 0.12s ease;
}

.btn:active { transform: scale(0.98); }

.btn-primary {
  width: 100%;
  background: var(--accent);
  color: var(--accent-ink);
}

.btn-primary:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.btn-ghost {
  background: #121a17;
  border: 1px solid var(--line);
  color: var(--ink);
}

.btn-ghost:hover { background: var(--card-hover); }

.meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
  color: var(--muted);
  font-size: 0.88rem;
  font-weight: 600;
}

.meta .num {
  font-family: "JetBrains Mono", monospace;
  color: var(--accent);
}

.card {
  min-height: 280px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 22px;
  padding: 22px 20px;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: 14px;
  user-select: none;
  -webkit-user-select: none;
  transition: border-color 0.15s ease, background 0.15s ease;
}

.card.open {
  border-color: rgba(62, 207, 142, 0.45);
  background: linear-gradient(180deg, #1d2b24 0%, var(--card) 55%);
}

.card .hint {
  color: var(--muted);
  font-size: 0.82rem;
}

.card .block {
  color: var(--warn);
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: none;
  letter-spacing: 0.01em;
}

.card .q {
  margin: 0;
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.25;
}

.answer {
  margin-top: auto;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  display: grid;
  gap: 12px;
}

.answer p {
  margin: 0;
  white-space: pre-wrap;
  line-height: 1.45;
  font-size: 1rem;
}

.answer .label {
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.answer .follow {
  padding: 12px;
  border-radius: 12px;
  background: #121a17;
  border: 1px solid var(--line);
}

.nav {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 10px;
  margin-top: 14px;
}

.nav .btn { width: 100%; min-height: 46px; font-size: 0.92rem; }

.toolbar {
  display: flex;
  gap: 10px;
  margin-top: 12px;
}

.toolbar .btn { flex: 1; }

.err {
  color: #ff8f8f;
  background: rgba(255, 107, 107, 0.1);
  border: 1px solid rgba(255, 107, 107, 0.35);
  border-radius: 12px;
  padding: 12px 14px;
  margin-bottom: 14px;
}

.empty {
  color: var(--muted);
  text-align: center;
  padding: 40px 12px;
}