:root {
  --ink: #25314d;
  --muted: #66708e;
  --paper: #fffaf0;
  --card: #ffffff;
  --sun: #ffc857;
  --mint: #8bd7c1;
  --coral: #ff7a6b;
  --sky: #7bb7ff;
  --shadow: 0 24px 60px rgba(37, 49, 77, 0.18);
  --radius: 24px;
}

* {
  box-sizing: border-box;
}

body {
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  font-family: "Marker Felt", "Trebuchet MS", "PingFang SC", "Hiragino Sans GB", sans-serif;
  background:
    radial-gradient(circle at 16% 16%, rgba(255, 200, 87, 0.46) 0 14%, transparent 15%),
    radial-gradient(circle at 86% 22%, rgba(123, 183, 255, 0.42) 0 12%, transparent 13%),
    linear-gradient(135deg, #fff1cf 0%, #e4f8ee 52%, #e6f1ff 100%);
  display: grid;
  place-items: center;
  padding: 28px 16px;
}

body::before,
body::after {
  content: "";
  position: fixed;
  z-index: -1;
  border-radius: 999px;
  opacity: 0.8;
}

body::before {
  width: 160px;
  height: 160px;
  left: -48px;
  bottom: 10%;
  background: repeating-linear-gradient(45deg, rgba(255, 122, 107, 0.35) 0 12px, transparent 12px 24px);
}

body::after {
  width: 190px;
  height: 190px;
  right: -54px;
  bottom: -38px;
  background: radial-gradient(circle, rgba(139, 215, 193, 0.56) 0 52%, transparent 53%);
}

button,
select {
  font: inherit;
}

.app-shell {
  width: min(100%, 680px);
  padding: clamp(20px, 4vw, 34px);
  border: 4px solid rgba(255, 255, 255, 0.75);
  border-radius: 34px;
  background: rgba(255, 250, 240, 0.88);
  box-shadow: var(--shadow);
  backdrop-filter: blur(14px);
}

.hero {
  margin-bottom: 22px;
  text-align: center;
}

.eyebrow {
  display: inline-flex;
  margin: 0 0 8px;
  padding: 6px 14px;
  border-radius: 999px;
  color: #7b4d00;
  background: rgba(255, 200, 87, 0.4);
  font-size: 0.92rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(2.2rem, 7vw, 4rem);
  line-height: 1;
}

.hero p:last-child {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: clamp(1rem, 3.4vw, 1.25rem);
}

.control-panel {
  margin-bottom: 18px;
}

.settings-trigger {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 4px 12px;
  width: 100%;
  min-height: 62px;
  border: 2px solid rgba(37, 49, 77, 0.08);
  border-radius: 22px;
  color: var(--ink);
  background: rgba(255, 255, 255, 0.72);
  padding: 12px 16px;
  text-align: left;
  box-shadow: inset 0 0 0 4px rgba(255, 255, 255, 0.35);
  cursor: pointer;
}

.settings-trigger:disabled {
  cursor: not-allowed;
  opacity: 0.7;
}

.summary-label,
.summary-action {
  color: var(--muted);
  font-size: 0.88rem;
}

.summary-label {
  grid-column: 1;
}

.summary-action {
  grid-column: 2;
  grid-row: 1 / span 2;
  align-self: center;
  padding: 7px 10px;
  border-radius: 999px;
  background: rgba(139, 215, 193, 0.28);
}

#settings-summary {
  grid-column: 1;
  overflow: hidden;
  color: var(--ink);
  font-size: clamp(1rem, 3.8vw, 1.18rem);
  line-height: 1.25;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.settings-dialog,
.complete-dialog {
  width: min(calc(100vw - 32px), 560px);
  border: 0;
  border-radius: 28px;
  background: transparent;
  padding: 0;
  color: var(--ink);
}

.settings-dialog::backdrop,
.complete-dialog::backdrop {
  background: rgba(37, 49, 77, 0.36);
  backdrop-filter: blur(5px);
}

.settings-card,
.complete-card {
  padding: 20px;
  border: 3px solid rgba(255, 255, 255, 0.82);
  border-radius: 28px;
  background: rgba(255, 250, 240, 0.96);
  box-shadow: var(--shadow);
}

.complete-card {
  text-align: center;
}

.complete-card h2 {
  margin: 0;
  font-size: clamp(1.55rem, 6vw, 2rem);
}

.complete-card p {
  margin: 10px 0 18px;
  color: var(--muted);
  font-size: 1rem;
}

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

.primary-button,
.secondary-button {
  min-height: 48px;
  border: 0;
  border-radius: 18px;
  color: #1f2a44;
  cursor: pointer;
}

.primary-button {
  background: var(--mint);
  box-shadow: 0 8px 18px rgba(56, 146, 122, 0.2);
}

.secondary-button {
  background: rgba(255, 255, 255, 0.78);
}

.primary-button[hidden] {
  display: none;
}

.complete-actions:has(.primary-button[hidden]) {
  grid-template-columns: 1fr;
}

.settings-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 16px;
}

.settings-header p {
  margin: 0 0 4px;
  color: var(--muted);
  font-size: 0.9rem;
}

.settings-header h2 {
  margin: 0;
  font-size: clamp(1.3rem, 5vw, 1.8rem);
}

.icon-button {
  width: 40px;
  min-width: 40px;
  height: 40px;
  border: 0;
  border-radius: 999px;
  color: var(--ink);
  background: rgba(255, 255, 255, 0.78);
  cursor: pointer;
}

.settings-fields {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.settings-fields .field:nth-child(3) {
  grid-column: 1 / -1;
}

.done-button {
  width: 100%;
  min-height: 48px;
  margin-top: 16px;
  border: 0;
  border-radius: 18px;
  color: #1f2a44;
  background: var(--mint);
  box-shadow: 0 8px 18px rgba(56, 146, 122, 0.2);
  cursor: pointer;
}

.field {
  position: relative;
  display: flex;
  align-items: center;
  min-width: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.field span {
  position: absolute;
  left: 14px;
  z-index: 1;
  color: var(--muted);
  font-size: 0.82rem;
  pointer-events: none;
}

select {
  width: 100%;
  min-height: 44px;
  border: 2px solid rgba(37, 49, 77, 0.12);
  border-radius: 16px;
  color: var(--ink);
  background: var(--card);
  padding: 0 34px 0 52px;
  outline: none;
  overflow: hidden;
  text-overflow: ellipsis;
}

select:focus,
button:focus-visible {
  outline: 4px solid rgba(123, 183, 255, 0.5);
  outline-offset: 2px;
}

.message {
  margin-bottom: 14px;
  padding: 12px 16px;
  border-radius: 18px;
  color: #8a3b22;
  background: rgba(255, 122, 107, 0.2);
}

.word-card {
  position: relative;
  display: grid;
  place-items: center;
  width: 100%;
  min-height: clamp(240px, 48vh, 340px);
  border: 0;
  border-radius: var(--radius);
  color: var(--ink);
  background: transparent;
  box-shadow: 0 16px 36px rgba(37, 49, 77, 0.14);
  cursor: pointer;
  perspective: 1200px;
  transition: transform 180ms ease, box-shadow 180ms ease;
}

.word-card:not(:disabled):hover {
  transform: translateY(-3px) rotate(-0.3deg);
  box-shadow: 0 20px 44px rgba(37, 49, 77, 0.2);
}

.word-card:disabled {
  cursor: default;
  opacity: 0.78;
}

.card-inner {
  position: absolute;
  inset: 0;
  display: block;
  border-radius: inherit;
  transform-style: preserve-3d;
  transition: transform 560ms cubic-bezier(0.2, 0.75, 0.2, 1.1);
}

.word-card.is-flipped .card-inner {
  transform: rotateY(180deg);
}

.card-side {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  overflow: hidden;
  border-radius: inherit;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

.card-side::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    linear-gradient(160deg, rgba(255, 255, 255, 0.92), rgba(255, 255, 255, 0.76)),
    radial-gradient(circle at 18% 24%, rgba(255, 200, 87, 0.28), transparent 28%),
    radial-gradient(circle at 82% 80%, rgba(139, 215, 193, 0.4), transparent 30%);
}

.card-side-back {
  transform: rotateY(180deg);
}

.card-side-back::before {
  background:
    linear-gradient(160deg, rgba(255, 255, 255, 0.94), rgba(255, 255, 255, 0.78)),
    radial-gradient(circle at 18% 24%, rgba(123, 183, 255, 0.34), transparent 28%),
    radial-gradient(circle at 82% 80%, rgba(255, 122, 107, 0.28), transparent 30%);
}

.card-face {
  display: block;
  padding: 20px;
  font-size: clamp(2.25rem, 10vw, 3.75rem);
  font-weight: 800;
  line-height: 1.15;
  text-align: center;
}

.card-side-back .card-face {
  font-size: clamp(2.6rem, 11vw, 4.4rem);
}

.card-hint {
  position: absolute;
  right: 18px;
  bottom: 18px;
  left: 18px;
  color: #aeb6c6;
  font-size: clamp(0.95rem, 3vw, 1.1rem);
  text-align: center;
}

@media (prefers-reduced-motion: reduce) {
  .card-inner,
  .word-card {
    transition: none;
  }
}

.practice-actions {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 14px;
  margin-top: 18px;
}

.nav-button {
  min-height: 48px;
  border: 0;
  border-radius: 16px;
  color: #1f2a44;
  background: var(--sun);
  box-shadow: 0 8px 18px rgba(173, 112, 0, 0.18);
  cursor: pointer;
}

.nav-button:last-child {
  background: var(--mint);
}

.nav-button:disabled {
  color: rgba(37, 49, 77, 0.42);
  background: rgba(255, 255, 255, 0.64);
  box-shadow: none;
  cursor: not-allowed;
}

.progress {
  min-width: 72px;
  color: var(--ink);
  font-size: 1.2rem;
  text-align: center;
}

@media (max-width: 620px) {
  body {
    padding: 14px;
  }

  .app-shell {
    padding: 18px;
    border-radius: 26px;
  }

  .control-panel {
    margin-bottom: 14px;
  }

  .settings-trigger {
    min-height: 58px;
    padding: 11px 14px;
  }

  .summary-action {
    padding: 6px 9px;
    font-size: 0.78rem;
  }

  .settings-card {
    padding: 18px;
  }

  .complete-card {
    padding: 18px;
  }

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

  .settings-fields {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .settings-fields .field:nth-child(3) {
    grid-column: auto;
  }

  .field {
    font-size: 0.88rem;
  }

  .field span {
    left: 12px;
    font-size: 0.76rem;
  }

  select {
    min-height: 42px;
    border-radius: 14px;
    padding-right: 30px;
    padding-left: 46px;
  }

  .practice-actions {
    grid-template-columns: 1fr 76px 1fr;
    gap: 8px;
  }
}