:root {
  --ink: #1c2430;
  --muted: #5c6b7a;
  --paper: #f3efe6;
  --panel: rgba(255, 252, 246, 0.92);
  --line: #d5cdc0;
  --accent: #0f6e56;
  --accent-soft: #d8f0e6;
  --warn: #b45309;
  --wrong: #b42318;
  --ok: #0f6e56;
  --shadow: 0 18px 50px rgba(28, 36, 48, 0.12);
  --radius: 18px;
  --font-display: "Fraunces", Georgia, serif;
  --font-body: "IBM Plex Sans", "PingFang SC", "Hiragino Sans GB", sans-serif;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  font-family: var(--font-body);
  color: var(--ink);
  background:
    radial-gradient(1200px 600px at 10% -10%, #cfe8dc 0%, transparent 55%),
    radial-gradient(900px 500px at 100% 0%, #efe2c8 0%, transparent 50%),
    linear-gradient(165deg, #e9e2d4 0%, #f6f2ea 45%, #e7eee9 100%);
}

.login-gate {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: grid;
  place-items: center;
  padding: 1.2rem;
  background: rgba(28, 36, 48, 0.35);
  backdrop-filter: blur(6px);
}

.login-panel {
  width: min(420px, 100%);
  text-align: left;
}

.login-panel h1 {
  margin: 0.3rem 0 0.4rem;
  font-family: var(--font-display);
  font-size: 1.8rem;
}

.login-panel input {
  width: 100%;
  border: 1.5px solid var(--line);
  border-radius: 12px;
  padding: 0.85rem 0.95rem;
  font: inherit;
  margin-bottom: 0.7rem;
  background: #fff;
}

.login-error {
  color: var(--wrong);
  font-size: 0.9rem;
  margin: 0 0 0.7rem;
}

.bg-glow {
  position: fixed;
  inset: auto -10% -20% auto;
  width: 420px;
  height: 420px;
  background: radial-gradient(circle, rgba(15, 110, 86, 0.18), transparent 70%);
  pointer-events: none;
  filter: blur(10px);
}

.app {
  width: min(720px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 2.5rem 0 4rem;
}

.hero {
  margin-bottom: 1.5rem;
  animation: rise 0.55s ease both;
}

.brand {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.65rem;
  letter-spacing: 0.02em;
  color: var(--accent);
}

.hero h1 {
  margin: 0.35rem 0 0.25rem;
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 700;
  line-height: 1.15;
}

.sub {
  margin: 0;
  color: var(--muted);
}

.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.35rem 1.4rem 1.5rem;
  backdrop-filter: blur(8px);
  animation: rise 0.6s ease both;
  animation-delay: 0.05s;
}

.field {
  margin-bottom: 1.15rem;
}

.label {
  display: block;
  margin-bottom: 0.45rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--muted);
  letter-spacing: 0.04em;
}

.hint {
  margin: 0.45rem 0 0;
  font-size: 0.85rem;
  color: var(--muted);
}

.seg {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.seg-btn {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
  border-radius: 999px;
  padding: 0.5rem 0.95rem;
  font: inherit;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease, transform 0.15s ease;
}

.seg-btn:hover {
  transform: translateY(-1px);
}

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

select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.7rem 0.85rem;
  font: inherit;
  background: #fff;
  color: var(--ink);
}

.checks {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.5rem;
}

.check {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.55rem 0.7rem;
  background: #fff;
  cursor: pointer;
  user-select: none;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.check:has(input:checked) {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.check input {
  accent-color: var(--accent);
}

.primary,
.ghost {
  font: inherit;
  font-weight: 600;
  border-radius: 12px;
  padding: 0.75rem 1.1rem;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.2s ease, opacity 0.2s ease;
}

.primary {
  width: 100%;
  border: none;
  background: var(--accent);
  color: #fff;
}

.primary:hover {
  transform: translateY(-1px);
  filter: brightness(1.05);
}

.ghost {
  border: 1px solid var(--line);
  background: transparent;
  color: var(--ink);
}

.ghost:hover {
  background: rgba(255, 255, 255, 0.7);
}

.hidden {
  display: none !important;
}

.quiz-top {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 0.75rem;
  align-items: center;
  margin-bottom: 1.2rem;
}

.quiz-top .ghost {
  padding: 0.4rem 0.7rem;
  font-size: 0.9rem;
}

.progress-wrap {
  display: grid;
  gap: 0.25rem;
}

.progress-bar {
  height: 8px;
  border-radius: 999px;
  background: #e5ddd0;
  overflow: hidden;
}

.progress-bar span {
  display: block;
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, #0f6e56, #2a9d7c);
  transition: width 0.35s ease;
}

.progress-text,
.score {
  font-size: 0.85rem;
  color: var(--muted);
  font-weight: 600;
}

.score {
  color: var(--ok);
}

.prompt-box {
  border-radius: 16px;
  border: 1px dashed #cbbfae;
  background: linear-gradient(180deg, #fffdf8, #f7f1e6);
  padding: 1.4rem 1.1rem;
  min-height: 8.5rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  margin-bottom: 1.1rem;
  animation: fade-in 0.35s ease both;
}

.prompt-label {
  margin: 0 0 0.5rem;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--muted);
  text-transform: uppercase;
}

.prompt-meta-right {
  display: flex;
  align-items: center;
  gap: 0.55rem;
}

.speak-btn {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--accent);
  border-radius: 8px;
  padding: 0.2rem 0.55rem;
  font: inherit;
  font-size: 0.78rem;
  font-weight: 700;
  cursor: pointer;
  white-space: nowrap;
}

.speak-btn:hover {
  background: var(--accent-soft);
  border-color: var(--accent);
}

.speak-word {
  cursor: pointer;
  border-bottom: 1px dashed rgba(15, 110, 86, 0.45);
  transition: color 0.15s ease, background 0.15s ease;
}

.speak-word:hover {
  color: var(--accent);
  background: rgba(15, 110, 86, 0.08);
}

.prompt-text.speakable {
  cursor: pointer;
}

.word-item .en .speak-word {
  font-weight: 600;
}

.prompt-text {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 3.5vw, 1.85rem);
  line-height: 1.45;
  word-break: break-word;
}

.prompt-text.en {
  font-family: var(--font-body);
  font-weight: 600;
  letter-spacing: 0.02em;
}

.answer-form .input-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.6rem;
  align-items: center;
}

#answer-input {
  width: 100%;
  border: 1.5px solid var(--line);
  border-radius: 12px;
  padding: 0.85rem 0.95rem;
  font: inherit;
  font-size: 1.05rem;
  background: #fff;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

#answer-input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(15, 110, 86, 0.15);
}

#answer-input.ok {
  border-color: var(--ok);
  background: #f1faf6;
}

#answer-input.bad {
  border-color: var(--wrong);
  background: #fff5f4;
}

.verdict {
  min-width: 2rem;
  text-align: center;
  font-size: 1.55rem;
  font-weight: 700;
  line-height: 1;
  opacity: 0;
  transform: scale(0.6);
  transition: opacity 0.2s ease, transform 0.25s cubic-bezier(0.2, 0.9, 0.3, 1.3);
}

.verdict.show {
  opacity: 1;
  transform: scale(1);
}

.verdict.ok {
  color: var(--ok);
}

.verdict.bad {
  color: var(--wrong);
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin-top: 0.9rem;
}

.actions .primary,
.actions .ghost {
  width: auto;
  flex: 1 1 auto;
  min-width: 5.5rem;
}

.hint-box {
  margin: 0.75rem 0 0;
  padding: 0.75rem 0.9rem;
  border-radius: 12px;
  border: 1px solid #b7d9cc;
  background: #eef8f3;
  color: var(--accent);
  font-size: 0.98rem;
  line-height: 1.45;
  animation: fade-in 0.3s ease both;
}

.reveal {
  margin: 0.9rem 0 0;
  padding: 0.75rem 0.9rem;
  border-radius: 12px;
  background: #fff7ed;
  color: var(--warn);
  font-size: 0.95rem;
  animation: fade-in 0.3s ease both;
}

.done {
  text-align: center;
  padding: 2rem 1.4rem;
}

.done h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 2rem;
}

.done-stat {
  margin: 0.8rem 0 1.4rem;
  color: var(--muted);
  font-size: 1.05rem;
}

.done .actions {
  justify-content: center;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fade-in {
  from {
    opacity: 0;
    transform: translateY(6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.study-list {
  display: grid;
  gap: 0.55rem;
  max-height: min(70vh, 720px);
  overflow: auto;
  padding-right: 0.15rem;
}

.study-item {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.65rem 0.85rem;
  align-items: start;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff;
  padding: 0.75rem 0.85rem;
  cursor: pointer;
  transition: border-color 0.2s ease, background 0.2s ease, transform 0.15s ease;
}

.study-item:hover {
  border-color: #9fc9b8;
  transform: translateY(-1px);
}

.study-item.selected {
  border-color: var(--accent);
  background: #f3faf7;
}

.study-item.speaking {
  box-shadow: 0 0 0 3px rgba(15, 110, 86, 0.15);
}

.study-item .speak-icon {
  display: inline-block;
  margin-left: 0.35rem;
  padding: 0.05rem 0.35rem;
  border-radius: 6px;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  vertical-align: middle;
  background: #e7f3ee;
  color: var(--accent);
  opacity: 0.55;
}

.study-item.selected .speak-icon,
.study-item:hover .speak-icon {
  opacity: 0.9;
}

.study-item .idx {
  width: 2rem;
  color: var(--muted);
  font-size: 0.85rem;
  font-weight: 600;
  padding-top: 0.15rem;
}

.study-item .en {
  margin: 0;
  font-weight: 600;
  font-size: 1.05rem;
  letter-spacing: 0.01em;
}

.study-item .zh {
  margin: 0.25rem 0 0;
  color: var(--muted);
  line-height: 1.45;
}

.study-item .tags {
  grid-column: auto;
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-top: 0.35rem;
  min-height: 1.1rem;
}

.study-actions {
  margin-top: 0.45rem;
}

.study-special-btn {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
  border-radius: 8px;
  padding: 0.3rem 0.65rem;
  font: inherit;
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
}

.study-special-btn.active {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
}

.study-item .tag {
  font-size: 0.72rem;
  font-weight: 600;
  padding: 0.15rem 0.45rem;
  border-radius: 999px;
  background: #f0ebe3;
  color: var(--muted);
}

.study-item .tag.wrong {
  background: #fde8e6;
  color: var(--wrong);
}

.study-item .tag.special {
  background: var(--accent-soft);
  color: var(--accent);
}

.stats-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem 1rem;
  margin: 0.2rem 0 1.1rem;
  padding: 0.7rem 0.85rem;
  border-radius: 12px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.9rem;
  font-weight: 600;
}

.linkish {
  border: none;
  background: none;
  color: var(--ink);
  font: inherit;
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 3px;
  cursor: pointer;
  padding: 0;
}

.linkish.danger {
  color: var(--wrong);
}

.prompt-meta {
  display: flex;
  justify-content: space-between;
  gap: 0.75rem;
  align-items: baseline;
  margin-bottom: 0.35rem;
}

.prompt-meta .prompt-label {
  margin: 0;
}

.word-stat {
  margin: 0;
  font-size: 0.8rem;
  color: var(--muted);
  font-weight: 500;
}

.secondary-actions {
  margin-top: 0.55rem;
}

.special-btn.active {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
}

.lists-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.lists-top h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.55rem;
}

.label-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.45rem;
}

.label-row .label {
  margin: 0;
}

.word-list {
  display: grid;
  gap: 0.45rem;
  max-height: 280px;
  overflow: auto;
  padding-right: 0.2rem;
}

.word-item {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.5rem;
  align-items: start;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff;
  padding: 0.65rem 0.75rem;
}

.word-item .en {
  font-weight: 600;
}

.word-item .zh {
  margin-top: 0.2rem;
  color: var(--muted);
  font-size: 0.88rem;
}

.word-item .meta {
  color: var(--warn);
  font-size: 0.82rem;
  font-weight: 600;
  white-space: nowrap;
}

.word-item .item-actions {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.word-item button {
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 8px;
  padding: 0.25rem 0.5rem;
  font: inherit;
  font-size: 0.78rem;
  cursor: pointer;
}

.word-list .empty {
  color: var(--muted);
  font-size: 0.9rem;
  padding: 0.6rem 0.2rem;
}

@media (max-width: 560px) {
  .checks {
    grid-template-columns: 1fr;
  }

  .quiz-top {
    grid-template-columns: 1fr;
  }

  .score {
    justify-self: start;
  }
}