:root {
  --green: #2f6f4f;
  --green-dark: #234f38;
  --red: #b3462c;
  --amber: #b98a1e;
  --bg: #f7f6f2;
  --card-bg: #ffffff;
  --text: #222;
  --muted: #6b6b6b;
  --border: #e2e0d8;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding-block: env(safe-area-inset-top, 0px) env(safe-area-inset-bottom, 0px);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
}

main {
  max-width: 640px;
  margin: 0 auto;
  padding: 16px 16px 48px;
}

.topnav {
  display: flex;
  gap: 16px;
  align-items: center;
  padding: 14px 16px;
  padding-top: calc(14px + env(safe-area-inset-top, 0px));
  background: var(--green);
  position: sticky;
  top: 0;
  z-index: 10;
}
.topnav a { color: #fff; text-decoration: none; font-size: 15px; }
.topnav .brand { font-weight: 600; margin-right: auto; font-size: 17px; }

h1 { font-size: 22px; margin: 8px 0 16px; }
h2 { font-size: 16px; margin: 0 0 10px; color: var(--green-dark); }

.muted { color: var(--muted); font-size: 14px; }

.goal-card, .deck-card, .card-box {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  margin-bottom: 16px;
}

.progress-bar {
  background: var(--border);
  border-radius: 999px;
  height: 10px;
  overflow: hidden;
  margin-bottom: 8px;
}
.progress-fill { background: var(--green); height: 100%; }

.deck-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
@media (max-width: 480px) {
  .deck-grid { grid-template-columns: 1fr; }
}
.due-count { font-size: 32px; font-weight: 700; margin: 4px 0 0; color: var(--green-dark); }

.btn {
  display: inline-block;
  background: var(--green);
  color: #fff;
  border: none;
  border-radius: 8px;
  padding: 10px 16px;
  font-size: 15px;
  text-decoration: none;
  cursor: pointer;
  margin-top: 10px;
}
.btn-secondary { background: #8a8672; }
.btn-again { background: var(--red); }
.btn-hard { background: var(--amber); }
.btn-good { background: var(--green); }

.tabs { display: flex; gap: 8px; margin-bottom: 16px; }
.tab {
  padding: 8px 14px;
  border-radius: 999px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  color: var(--text);
  text-decoration: none;
  font-size: 14px;
}
.tab-active { background: var(--green); color: #fff; border-color: var(--green); }

label { display: block; font-size: 14px; margin-bottom: 8px; color: var(--muted); }
code { background: #eee; padding: 1px 5px; border-radius: 4px; }
textarea {
  width: 100%;
  font-size: 15px;
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-family: inherit;
}

.card-box { text-align: center; padding: 32px 16px; }
.card-front { font-size: 26px; font-weight: 600; margin-bottom: 16px; }
.card-back { margin-bottom: 16px; }
.card-back-text { font-size: 20px; color: var(--green-dark); font-weight: 600; }
.card-example { font-size: 14px; color: var(--muted); margin-top: 6px; font-style: italic; }
.hidden { display: none !important; }
.rating-form { display: flex; gap: 8px; justify-content: center; flex-wrap: wrap; }
.rating-form .btn { margin-top: 0; }

.empty-state { font-size: 18px; text-align: center; margin: 32px 0 16px; }

.stats-table { width: 100%; border-collapse: collapse; }
.stats-table th, .stats-table td { text-align: left; padding: 8px; border-bottom: 1px solid var(--border); }
.stats-table .current-month { font-weight: 700; }

.flashes { margin-bottom: 16px; }
.flash { padding: 10px 14px; border-radius: 8px; margin-bottom: 8px; font-size: 14px; }
.flash-success { background: #e3f1e8; color: var(--green-dark); }
.flash-warning { background: #f8ecd6; color: var(--amber); }

section { margin-bottom: 24px; }