:root {
  --bg-0: #f3f7fc;
  --bg-1: #e8eef9;
  --panel: #ffffff;
  --panel-border: #d5e0ee;
  --text: #152238;
  --muted: #5c6f8b;
  --accent: #0a7cff;
  --success: #22a06b;
  --danger: #d14343;
  --hint: #e4901b;
  --shadow: 0 16px 45px rgba(14, 38, 74, 0.12);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "JetBrains Mono", "Fira Code", "Cascadia Code", monospace;
  color: var(--text);
  background:
    radial-gradient(circle at 12% 10%, rgba(10, 124, 255, 0.14), transparent 40%),
    radial-gradient(circle at 86% 82%, rgba(34, 160, 107, 0.12), transparent 36%),
    linear-gradient(160deg, var(--bg-0), var(--bg-1));
  display: grid;
  place-items: center;
  padding: 24px;
}

.app {
  width: min(980px, 100%);
  border: 1px solid var(--panel-border);
  border-radius: 16px;
  box-shadow: var(--shadow);
  overflow: hidden;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(255, 255, 255, 0.95));
  animation: rise 420ms ease;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.screen {
  display: block;
}

.screen.hidden {
  display: none;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 18px;
  border-bottom: 1px solid var(--panel-border);
  background: rgba(10, 124, 255, 0.04);
}

.title {
  font-size: 14px;
  color: var(--muted);
  letter-spacing: 0.02em;
}

.status-area {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.badge {
  font-size: 13px;
  font-weight: 700;
  border-radius: 999px;
  padding: 4px 10px;
  min-width: 100px;
  text-align: center;
}

.score {
  color: var(--accent);
  background: rgba(10, 124, 255, 0.12);
  border: 1px solid rgba(10, 124, 255, 0.22);
}

.mistakes {
  color: #8f2525;
  background: rgba(209, 67, 67, 0.14);
  border: 1px solid rgba(209, 67, 67, 0.24);
}

.home {
  padding: clamp(20px, 6vw, 56px);
  text-align: left;
}

.home-layout {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 22px;
  align-items: stretch;
}

.home-main {
  display: grid;
  gap: 20px;
}

.home h1 {
  margin: 0;
  font-size: clamp(28px, 5vw, 46px);
  letter-spacing: -0.02em;
}

.user {
  color: #18508f;
  background: rgba(24, 80, 143, 0.1);
  border: 1px solid rgba(24, 80, 143, 0.2);
}

.logout-btn {
  border: 1px solid rgba(209, 67, 67, 0.26);
  background: rgba(209, 67, 67, 0.08);
  color: #8f2525;
}

.rules {
  max-width: 760px;
  margin: 0;
  color: var(--muted);
  line-height: 1.65;
  border: 1px solid var(--panel-border);
  background: #fbfdff;
  border-radius: 14px;
  padding: 16px;
  font-size: 15px;
  text-align: left;
}

.difficulty {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
}

.difficulty-btn {
  appearance: none;
  border: 1px solid var(--panel-border);
  border-radius: 12px;
  background: #fff;
  color: var(--text);
  padding: 10px 18px;
  font: inherit;
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  transition: transform 120ms ease, border-color 120ms ease, background-color 120ms ease;
}

.difficulty-btn:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
}

.difficulty-btn.selected {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(10, 124, 255, 0.09);
}

.play-btn {
  border: none;
  color: #fff;
  background: linear-gradient(130deg, #0a7cff, #0967d2);
  border-radius: 12px;
  font-size: 18px;
  font-weight: 700;
  padding: 14px 32px;
  cursor: pointer;
  box-shadow: 0 10px 28px rgba(10, 124, 255, 0.32);
  transition: transform 150ms ease, filter 150ms ease;
}

.play-btn:hover:not(:disabled) {
  transform: translateY(-1px);
  filter: brightness(1.03);
}

.play-btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  box-shadow: none;
}

.home-note {
  margin: 0;
  font-size: 13px;
  color: var(--muted);
}

.scoreboard {
  border: 1px solid var(--panel-border);
  border-radius: 14px;
  background: linear-gradient(180deg, #ffffff, #f7fbff);
  padding: 14px;
  display: grid;
  gap: 12px;
}

.scoreboard h2 {
  margin: 0;
  font-size: 20px;
}

.scoreboard-tabs {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
}

.scoreboard-tab {
  appearance: none;
  border: 1px solid var(--panel-border);
  border-radius: 10px;
  background: #fff;
  color: var(--muted);
  font: inherit;
  font-weight: 700;
  font-size: 13px;
  padding: 8px 10px;
  cursor: pointer;
}

.scoreboard-tab.active {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(10, 124, 255, 0.1);
}

.scoreboard-status {
  margin: 0;
  font-size: 13px;
  color: var(--muted);
}

.scoreboard-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 8px;
  max-height: 320px;
  overflow: auto;
}

.scoreboard-item {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 10px;
  align-items: center;
  border: 1px solid var(--panel-border);
  border-radius: 10px;
  background: #fff;
  padding: 8px 10px;
}

.scoreboard-rank {
  color: var(--accent);
  font-weight: 700;
}

.scoreboard-name {
  font-weight: 700;
  word-break: break-word;
}

.scoreboard-value {
  color: #1f7f59;
  font-weight: 700;
}

.auth-shell {
  width: min(920px, 100%);
  display: grid;
  place-items: center;
}

.auth-card {
  width: min(460px, 100%);
  border: 1px solid var(--panel-border);
  border-radius: 16px;
  background: linear-gradient(170deg, #ffffff, #f4f9ff);
  box-shadow: var(--shadow);
  padding: 24px;
  display: grid;
  gap: 12px;
}

.auth-kicker {
  margin: 0;
  color: var(--accent);
  font-weight: 700;
  font-size: 13px;
}

.auth-card h1 {
  margin: 0;
  font-size: 34px;
}

.auth-description {
  margin: 0;
  color: var(--muted);
  line-height: 1.6;
}

.auth-form {
  display: grid;
  gap: 8px;
}

.auth-label {
  font-size: 13px;
  color: var(--muted);
}

.auth-input {
  appearance: none;
  border: 1px solid var(--panel-border);
  border-radius: 10px;
  font: inherit;
  font-size: 14px;
  padding: 10px 12px;
}

.auth-input:focus {
  outline: 2px solid rgba(10, 124, 255, 0.24);
  border-color: var(--accent);
}

.auth-submit {
  margin-top: 8px;
}

.auth-message {
  min-height: 22px;
  margin: 0;
  color: var(--muted);
  font-size: 13px;
}

.auth-message.is-error {
  color: var(--danger);
}

.auth-message.is-success {
  color: var(--success);
}

.auth-toggle {
  appearance: none;
  border: 1px solid var(--panel-border);
  border-radius: 10px;
  background: #fff;
  color: var(--text);
  font: inherit;
  font-size: 13px;
  font-weight: 700;
  padding: 10px;
  cursor: pointer;
}

.content {
  padding: 24px clamp(16px, 3vw, 32px);
  display: grid;
  gap: 14px;
}

.meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  color: var(--muted);
  font-size: 13px;
}

.topic {
  font-weight: 700;
  color: var(--text);
  font-size: 14px;
}

.paragraph {
  line-height: 1.9;
  font-size: clamp(16px, 1.7vw, 18px);
  margin: 0;
  min-height: 100px;
  border: 1px solid var(--panel-border);
  border-radius: 12px;
  padding: 16px;
  background: #fbfdff;
  word-wrap: break-word;
}

.word {
  border-radius: 6px;
  cursor: pointer;
  padding: 2px 3px;
  transition: background-color 160ms ease, color 160ms ease;
}

.word:hover {
  background: rgba(10, 124, 255, 0.12);
}

.word.success {
  background: rgba(34, 160, 107, 0.2);
  color: #0f6f47;
  font-weight: 700;
}

.word.hinted {
  background: rgba(228, 144, 27, 0.24);
  color: #8f580a;
  font-weight: 700;
}

.word.fail {
  background: rgba(209, 67, 67, 0.18);
  color: #8f2525;
}

.actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.action-btn {
  appearance: none;
  border-radius: 10px;
  padding: 8px 12px;
  font: inherit;
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  transition: transform 120ms ease;
}

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

.show-answers-btn {
  border: 1px solid rgba(228, 144, 27, 0.35);
  background: rgba(228, 144, 27, 0.14);
  color: #8f580a;
}

.back-menu-btn {
  border: 1px solid var(--panel-border);
  background: #fff;
  color: var(--muted);
}

.explanations {
  border: 1px solid var(--panel-border);
  border-radius: 12px;
  padding: 14px;
  min-height: 130px;
  background: var(--panel);
}

.explanations h2 {
  margin: 0 0 10px;
  font-size: 14px;
  color: var(--muted);
  font-weight: 600;
  letter-spacing: 0.02em;
}

.explanation-list {
  margin: 0;
  padding-left: 18px;
  display: grid;
  gap: 8px;
  font-size: 14px;
}

.hint {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  border-top: 1px solid var(--panel-border);
  padding: 14px 18px;
  background: rgba(10, 124, 255, 0.03);
}

.progress {
  color: var(--muted);
  font-size: 13px;
  text-align: center;
}

.nav-btn {
  appearance: none;
  border: 1px solid var(--panel-border);
  background: #fff;
  color: var(--text);
  border-radius: 10px;
  padding: 8px 14px;
  font: inherit;
  font-size: 14px;
  cursor: pointer;
  transition: transform 120ms ease, border-color 120ms ease;
}

.nav-btn:hover:not(:disabled) {
  border-color: var(--accent);
  transform: translateY(-1px);
}

.nav-btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 28, 48, 0.22);
  display: grid;
  place-items: center;
  padding: 20px;
  z-index: 20;
}

.modal-overlay.hidden {
  display: none;
}

.modal {
  width: min(440px, 100%);
  border-radius: 14px;
  border: 1px solid var(--panel-border);
  background: #fff;
  box-shadow: var(--shadow);
  padding: 24px;
  display: grid;
  gap: 14px;
  text-align: center;
}

.modal h2 {
  margin: 0;
  font-size: 28px;
  color: #8f2525;
}

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

.return-btn {
  appearance: none;
  border: none;
  border-radius: 10px;
  background: linear-gradient(130deg, #0a7cff, #0967d2);
  color: #fff;
  font: inherit;
  font-weight: 700;
  padding: 10px 14px;
  cursor: pointer;
}

@media (max-width: 680px) {
  .home-layout {
    grid-template-columns: 1fr;
  }

  .content {
    padding: 16px;
  }

  .paragraph {
    line-height: 1.75;
  }

  .controls {
    flex-wrap: wrap;
  }

  .play-btn {
    width: 100%;
  }

  .meta {
    flex-direction: column;
    align-items: flex-start;
  }

  .status-area {
    justify-content: flex-start;
  }

  .auth-card h1 {
    font-size: 28px;
  }
}