:root {
  color-scheme: light;
  --bg: #ffffff;
  --paper: #ffffff;
  --panel: #ffffff;
  --text: #111111;
  --muted: #555555;
  --line: #d9d9d9;
  --accent: #c5162e;
  --accent-strong: #990f21;
  --accent-soft: #fff1f3;
  --green: #1f7a55;
  --bad: #b91c1c;
  --good: #166534;
  --shadow: 0 10px 24px rgba(0, 0, 0, 0.08);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100svh;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans Thai", "Noto Sans JP", sans-serif;
}

button, input, select {
  font: inherit;
}

button {
  border: 0;
  cursor: pointer;
}

.app-shell {
  width: min(780px, 100%);
  margin: 0 auto;
  min-height: 100svh;
  padding: max(18px, env(safe-area-inset-top)) 16px calc(94px + env(safe-area-inset-bottom));
}

.screen { display: none; }
.screen.active { display: block; }

.brand-top {
  padding: 8px 2px 14px;
}

.brand-mark {
  display: inline-block;
  margin: 0 0 8px;
  padding: 5px 0;
  background: transparent;
  color: var(--accent);
  border-radius: 4px;
  font-weight: 900;
}

.topbar {
  padding: 10px 2px 16px;
}

.topbar.row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
}

.eyebrow {
  margin: 0 0 5px;
  color: var(--accent);
  font-size: 14px;
  font-weight: 900;
}

h1 {
  margin: 0;
  font-size: 30px;
  line-height: 1.14;
  letter-spacing: 0;
}

.category-rail {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  margin: 2px 0 14px;
}

.category-rail button {
  min-height: 46px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-bottom: 3px solid var(--accent);
  border-radius: 6px;
  color: var(--text);
  font-weight: 900;
}

.today-panel, .word-card, .quiz-card, .settings-panel, .history-box, .add-word-panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.today-panel {
  position: relative;
  overflow: hidden;
  padding: 22px;
  display: grid;
  gap: 12px;
}

.today-panel::before, .word-card::before, .quiz-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 6px;
  background: var(--accent);
}

.today-count {
  font-size: 46px;
  font-weight: 900;
}

.primary-action, .secondary-action, .home-links button, .rating-row button {
  min-height: 52px;
  border-radius: 6px;
  padding: 0 18px;
  font-weight: 900;
}

.primary-action {
  width: 100%;
  background: var(--accent);
  color: #fff;
}

.secondary-action, .home-links button {
  background: var(--paper);
  color: var(--text);
  border: 1px solid var(--line);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
  margin: 14px 0;
}

.stats-grid div {
  min-height: 86px;
  padding: 16px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-top: 4px solid var(--accent);
  border-radius: 6px;
}

.stats-grid span {
  display: block;
  font-size: 30px;
  font-weight: 900;
}

.stats-grid small {
  color: var(--muted);
}

.home-links, .study-actions, .rating-row, .form-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.rating-row {
  grid-template-columns: 1fr 1fr 1fr;
  margin-top: 12px;
}

.rating-row button:nth-child(1) { background: #fee2e2; color: #7f1d1d; }
.rating-row button:nth-child(2) { background: #f5f5f5; color: #333333; }
.rating-row button:nth-child(3) { background: #dcfce7; color: #14532d; }

.word-card {
  position: relative;
  min-height: 390px;
  padding: 32px 18px 28px;
  display: grid;
  place-items: center;
  text-align: center;
  touch-action: pan-y;
}

.thai-large {
  margin: 0;
  font-family: "Noto Sans Thai", "Tahoma", system-ui, sans-serif;
  font-size: clamp(64px, 18vw, 104px);
  line-height: 1.1;
  font-weight: 800;
  word-break: keep-all;
}

.answer {
  width: 100%;
  display: grid;
  gap: 8px;
}

.roman {
  margin: 0;
  font-size: 28px;
  color: var(--accent);
  font-weight: 900;
}

.meaning {
  margin: 0;
  font-size: 24px;
  font-weight: 850;
}

.chips {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  margin-top: 8px;
}

.chips span {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 8px 12px;
  color: var(--muted);
  background: var(--paper);
}

.icon-button {
  width: 54px;
  height: 54px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  font-size: 20px;
}

.hidden { display: none !important; }

.quiz-card {
  position: relative;
  padding: 22px 18px 18px;
  margin-bottom: 12px;
}

.question {
  margin: 4px 0 18px;
  font-size: 28px;
  font-weight: 900;
  line-height: 1.28;
}

.choices {
  display: grid;
  gap: 10px;
}

.choices button {
  min-height: 58px;
  border-radius: 6px;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--text);
  padding: 10px 14px;
  text-align: left;
  font-weight: 850;
}

.choices button.correct { border-color: var(--good); color: var(--good); }
.choices button.wrong { border-color: var(--bad); color: var(--bad); }

.quiz-result {
  margin-top: 14px;
  border-top: 1px solid var(--line);
  padding-top: 14px;
  color: var(--muted);
  line-height: 1.6;
}

.add-word-panel {
  margin-bottom: 12px;
  padding: 0;
  overflow: hidden;
}

.add-word-panel summary {
  padding: 16px;
  background: var(--accent);
  color: #fff;
  font-weight: 900;
  cursor: pointer;
}

.word-form {
  display: grid;
  gap: 12px;
  padding: 16px;
}

.word-form label, .settings-panel label {
  display: grid;
  gap: 7px;
  color: var(--muted);
  font-weight: 800;
}

.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.form-actions {
  grid-template-columns: 1fr 1fr 1fr;
}

.form-actions.two {
  grid-template-columns: 1fr 1fr;
}

.form-message {
  margin: 0;
  min-height: 22px;
  color: var(--accent);
  font-weight: 800;
}

.search, .filters select, .settings-panel input[type="number"], .word-form input, .word-form select {
  width: 100%;
  min-height: 48px;
  border-radius: 6px;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--text);
  padding: 0 12px;
}

.word-form input[type="file"] {
  padding: 10px;
}

.filters {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin: 10px 0;
}

.filters select:last-child {
  grid-column: 1 / -1;
}

.word-list {
  display: grid;
  gap: 9px;
}

.word-row {
  display: grid;
  grid-template-columns: minmax(74px, 100px) 1fr auto;
  gap: 10px;
  align-items: center;
  padding: 12px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-left: 4px solid var(--accent);
  border-radius: 6px;
  color: var(--text);
  text-align: left;
}

.word-row .thai {
  font-family: "Noto Sans Thai", "Tahoma", system-ui, sans-serif;
  font-size: 31px;
  font-weight: 900;
}

.word-row p {
  margin: 0;
}

.word-row small {
  color: var(--muted);
}

.status-dot {
  min-width: 50px;
  padding: 7px 9px;
  border-radius: 999px;
  text-align: center;
  font-size: 12px;
  font-weight: 900;
  background: #f4f4f4;
  color: var(--muted);
}

.status-dot.weak { color: var(--bad); }
.status-dot.known { color: var(--good); }
.status-dot.custom { color: var(--accent); }

.settings-panel, .history-box {
  padding: 16px;
  display: grid;
  gap: 14px;
}

.settings-panel .toggle, .word-form .toggle {
  grid-template-columns: auto 1fr;
  align-items: center;
}

.import-box input {
  padding: 10px 0;
}

.bottom-nav {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 4px;
  padding: 8px 10px calc(8px + env(safe-area-inset-bottom));
  background: rgba(255, 255, 255, 0.94);
  border-top: 1px solid var(--line);
  backdrop-filter: blur(18px);
}

.bottom-nav button {
  min-height: 50px;
  border-radius: 6px;
  background: transparent;
  color: var(--muted);
  font-size: 13px;
  font-weight: 900;
}

.bottom-nav button.active {
  background: var(--accent);
  color: #fff;
}

@media (min-width: 720px) {
  .stats-grid { grid-template-columns: repeat(4, 1fr); }
  .word-card { min-height: 430px; }
}

@media (max-width: 430px) {
  .form-grid, .form-actions {
    grid-template-columns: 1fr;
  }
}