:root {
  --bg-a: #f4f8ff;
  --bg-b: #e4eeff;
  --card: #ffffff;
  --text: #1f2937;
  --subtext: #5b6575;
  --accent: #1e5eff;
  --surface-border: rgba(0, 0, 0, 0.06);
  --toggle-bg: #dde8ff;
  --toggle-text: #1f3f96;
  --input-bg: #f7faff;
  --input-border: #c8d9ff;
  --chip-bg: #edf3ff;
  --chip-text: #1940b8;
  --shadow: 0 16px 40px rgba(0, 0, 0, 0.12);
  --btn-shadow: 0 10px 18px rgba(30, 94, 255, 0.28);
  --btn-shadow-hover: 0 12px 20px rgba(30, 94, 255, 0.32);
}

:root[data-theme="dark"] {
  --bg-a: #0f172a;
  --bg-b: #18233f;
  --card: #151d31;
  --text: #edf2ff;
  --subtext: #b4c0de;
  --accent: #4d82ff;
  --surface-border: rgba(255, 255, 255, 0.1);
  --toggle-bg: #273453;
  --toggle-text: #edf2ff;
  --input-bg: #1d2a48;
  --input-border: #384d7f;
  --chip-bg: #24365f;
  --chip-text: #dbe6ff;
  --shadow: 0 16px 40px rgba(0, 0, 0, 0.45);
  --btn-shadow: 0 10px 18px rgba(77, 130, 255, 0.35);
  --btn-shadow-hover: 0 12px 20px rgba(77, 130, 255, 0.4);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  font-family: "Pretendard", "Noto Sans KR", sans-serif;
  color: var(--text);
  background: linear-gradient(160deg, var(--bg-a), var(--bg-b));
  padding: 24px;
}

.app {
  width: min(900px, 100%);
  background: var(--card);
  border-radius: 20px;
  padding: 28px;
  border: 1px solid var(--surface-border);
  box-shadow: var(--shadow);
}

h1 {
  margin: 0 0 10px;
  font-size: clamp(1.5rem, 4vw, 2.1rem);
  text-align: center;
}

.topbar {
  display: flex;
  justify-content: flex-end;
  margin-bottom: 12px;
}

.theme-btn {
  border: 0;
  border-radius: 999px;
  padding: 8px 14px;
  font-size: 0.9rem;
  font-weight: 700;
  background: var(--toggle-bg);
  color: var(--toggle-text);
  cursor: pointer;
  transition: transform 120ms ease, opacity 120ms ease;
}

.theme-btn:hover {
  transform: translateY(-1px);
  opacity: 0.92;
}

p {
  margin: 0 0 24px;
  color: var(--subtext);
  text-align: center;
}

.lookup-form {
  display: flex;
  gap: 12px;
  margin-bottom: 12px;
}

.source-mode {
  display: flex;
  gap: 8px;
  margin-bottom: 10px;
}

.word-input {
  flex: 1;
  border: 1px solid var(--input-border);
  border-radius: 12px;
  background: var(--input-bg);
  color: var(--text);
  font-size: 1rem;
  padding: 12px 14px;
  outline: none;
}

.word-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent) 16%, transparent);
}

.search-btn {
  border: 0;
  border-radius: 12px;
  padding: 12px 18px;
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  background: var(--accent);
  cursor: pointer;
  transition: transform 120ms ease, box-shadow 120ms ease;
  box-shadow: var(--btn-shadow);
}

.search-btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--btn-shadow-hover);
}

.meaning-lang {
  display: flex;
  gap: 8px;
  margin-bottom: 14px;
}

.lang-btn {
  border: 1px solid var(--input-border);
  border-radius: 999px;
  background: var(--input-bg);
  color: var(--subtext);
  padding: 8px 12px;
  font-weight: 700;
  cursor: pointer;
}

.lang-btn.is-active {
  border-color: var(--accent);
  color: #fff;
  background: var(--accent);
}

.status {
  min-height: 22px;
  margin: 0 0 14px;
  color: var(--subtext);
  font-weight: 600;
}

.result-word {
  margin: 0 0 14px;
}

.result-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 6px;
}

.small-btn {
  border: 0;
  border-radius: 10px;
  padding: 8px 12px;
  font-size: 0.9rem;
  font-weight: 700;
  color: #fff;
  background: var(--accent);
  cursor: pointer;
}

.result {
  display: grid;
  grid-template-columns: repeat(1, minmax(0, 1fr));
  gap: 12px;
}

.extra-grid {
  display: grid;
  grid-template-columns: repeat(1, minmax(0, 1fr));
  gap: 12px;
  margin-top: 12px;
}

.card {
  border: 1px solid var(--surface-border);
  border-radius: 14px;
  padding: 14px;
}

.card h3 {
  margin: 0 0 10px;
  font-size: 1rem;
}

.list {
  margin: 0;
  padding-left: 18px;
  line-height: 1.6;
}

.chip-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 0;
  margin: 0;
  list-style: none;
}

.chip {
  border-radius: 999px;
  padding: 6px 10px;
  font-weight: 700;
  background: var(--chip-bg);
  color: var(--chip-text);
}

.example-ko {
  margin-top: 2px;
  color: var(--subtext);
  font-size: 0.95rem;
}

.muted {
  margin: 0 0 10px;
  color: var(--subtext);
  text-align: left;
  font-size: 0.95rem;
}

.saved-list {
  max-height: 220px;
  overflow: auto;
}

.saved-item {
  cursor: pointer;
  margin-bottom: 4px;
}

.saved-item b {
  margin-right: 6px;
}

.quiz-panel {
  margin-top: 8px;
}

.quiz-progress {
  margin: 0 0 8px;
  font-weight: 700;
}

.quiz-meaning {
  margin: 0 0 10px;
  line-height: 1.5;
}

.quiz-form {
  display: flex;
  gap: 10px;
}

.quiz-feedback {
  min-height: 20px;
  margin: 8px 0 0;
  font-weight: 700;
}

.quiz-summary {
  margin: 10px 0;
  font-weight: 700;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (min-width: 768px) {
  .result {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .extra-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 560px) {
  .lookup-form {
    flex-direction: column;
  }

  .source-mode {
    flex-direction: column;
  }

  .meaning-lang {
    flex-direction: column;
  }

  .quiz-form {
    flex-direction: column;
  }
}