:root {
  --bg: #0f172a;
  --card: #111827;
  --accent: #38bdf8;
  --accent-hover: #0ea5e9;
  --text: #e5e7eb;
  --muted: #94a3b8;
  --danger: #fb7185;
  --success: #34d399;
  --warning: #fbbf24;
  --tile: #1f2937;
  --tile-border: rgba(148, 163, 184, 0.35);
  --correct: #22c55e;
  --present: #eab308;
  --absent: #475569;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background:
    radial-gradient(circle at top left, rgba(56, 189, 248, 0.18), transparent 35%),
    radial-gradient(circle at bottom right, rgba(129, 140, 248, 0.16), transparent 35%),
    var(--bg);
  color: var(--text);
  padding: 2rem;
}

a {
  color: var(--accent);
}

.page {
  width: 100%;
  max-width: 820px;
  margin: 0 auto;
}

.topbar {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
  margin-bottom: 1.5rem;
}

.brand {
  color: var(--text);
  font-weight: 800;
  text-decoration: none;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: flex-end;
  gap: 0.8rem;
}

.nav a,
.link-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 38px;
  padding: 0.55rem 0.9rem;
  border-radius: 999px;
  border: 1px solid rgba(56, 189, 248, 0.35);
  background: rgba(56, 189, 248, 0.08);
  color: var(--accent);
  text-decoration: none;
  font: inherit;
  font-weight: 700;
  line-height: 1;
  cursor: pointer;
  transition:
    transform 0.16s ease,
    background 0.16s ease,
    border-color 0.16s ease,
    color 0.16s ease,
    box-shadow 0.16s ease;
}

.nav a:hover,
.link-button:hover {
  transform: translateY(-1px);
  background: rgba(56, 189, 248, 0.16);
  border-color: rgba(56, 189, 248, 0.65);
  color: var(--text);
  box-shadow: 0 10px 24px rgba(56, 189, 248, 0.12);
}

.nav form {
  margin: 0;
}

.card {
  width: 100%;
  background: rgba(17, 24, 39, 0.86);
  border: 1px solid rgba(148, 163, 184, 0.25);
  border-radius: 24px;
  padding: 3rem;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.35);
  backdrop-filter: blur(12px);
}

.auth-card {
  max-width: 620px;
  margin: 0 auto;
}

.badge {
  display: inline-block;
  margin-bottom: 1.5rem;
  padding: 0.45rem 0.8rem;
  border-radius: 999px;
  background: rgba(56, 189, 248, 0.12);
  color: var(--accent);
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

h1 {
  margin: 0 0 1rem;
  font-size: clamp(2rem, 5vw, 4rem);
  line-height: 1.05;
}

h2 {
  margin: 2rem 0 1rem;
  font-size: clamp(1.4rem, 3vw, 2rem);
}

p {
  margin: 0 0 1.3rem;
  color: var(--muted);
  font-size: 1.05rem;
  line-height: 1.7;
}

.small {
  margin-top: 1.5rem;
  font-size: 0.95rem;
}

.form {
  display: grid;
  gap: 1rem;
  margin-top: 1.6rem;
}

label {
  color: var(--text);
  font-weight: 700;
}

input {
  width: 100%;
  display: block;
  margin-top: 0.45rem;
  padding: 0.85rem 1rem;
  border-radius: 14px;
  border: 1px solid rgba(148, 163, 184, 0.35);
  background: rgba(15, 23, 42, 0.7);
  color: var(--text);
  font: inherit;
}

input:focus {
  outline: 2px solid rgba(56, 189, 248, 0.45);
  border-color: var(--accent);
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0.85rem 1.2rem;
  border-radius: 14px;
  border: 0;
  background: var(--accent);
  color: #082f49;
  font-weight: 800;
  font: inherit;
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.16s ease, background 0.16s ease, box-shadow 0.16s ease;
  box-shadow: 0 12px 30px rgba(56, 189, 248, 0.22);
}

.button:hover {
  background: var(--accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 16px 36px rgba(14, 165, 233, 0.28);
}

.button.secondary {
  background: transparent;
  color: var(--accent);
  border: 1px solid rgba(56, 189, 248, 0.55);
  box-shadow: none;
}

.button.secondary:hover {
  background: rgba(56, 189, 248, 0.12);
  color: var(--text);
}

.danger-button {
  background: var(--danger);
  color: #fff1f2;
}

.messages {
  margin-bottom: 1rem;
}

.message {
  border-radius: 16px;
  padding: 1rem;
  margin-bottom: 0.75rem;
  background: rgba(148, 163, 184, 0.12);
  border: 1px solid rgba(148, 163, 184, 0.25);
}

.message.error {
  border-color: rgba(251, 113, 133, 0.5);
  color: #fecdd3;
}

.message.success {
  border-color: rgba(52, 211, 153, 0.5);
  color: #bbf7d0;
}

.message.warning {
  border-color: rgba(251, 191, 36, 0.5);
  color: #fde68a;
}

.board {
  display: grid;
  gap: 0.55rem;
  margin: 2rem auto 1.5rem;
  width: min(100%, 360px);
}

.row {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.55rem;
}

.tile {
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  border-radius: 12px;
  border: 2px solid var(--tile-border);
  background: rgba(31, 41, 55, 0.72);
  color: var(--text);
  font-size: clamp(1.4rem, 5vw, 2rem);
  font-weight: 900;
  text-transform: uppercase;
  transition: transform 0.18s ease, background 0.18s ease, border 0.18s ease;
}

.tile.filled {
  border-color: rgba(56, 189, 248, 0.75);
  transform: scale(1.03);
}

.tile.correct {
  background: var(--correct);
  border-color: var(--correct);
  color: #052e16;
}

.tile.present {
  background: var(--present);
  border-color: var(--present);
  color: #422006;
}

.tile.absent {
  background: var(--absent);
  border-color: var(--absent);
  color: #e2e8f0;
}

.status {
  min-height: 1.8rem;
  text-align: center;
  color: var(--muted);
  margin: 1rem 0;
}

.game-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
  margin: 1rem 0;
}

.keyboard {
  display: grid;
  gap: 0.45rem;
  margin: 1.5rem auto 0;
  max-width: 620px;
}

.key-row {
  display: flex;
  gap: 0.45rem;
  justify-content: center;
}

.key {
  min-width: 2rem;
  min-height: 2.6rem;
  border: 0;
  border-radius: 10px;
  background: rgba(148, 163, 184, 0.22);
  color: var(--text);
  font-weight: 800;
  cursor: pointer;
}

.key.wide {
  min-width: 4.4rem;
}

.key.correct {
  background: var(--correct);
  color: #052e16;
}

.key.present {
  background: var(--present);
  color: #422006;
}

.key.absent {
  background: var(--absent);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 1rem;
  margin: 2rem 0;
}

.stat {
  padding: 1.2rem;
  border-radius: 18px;
  background: rgba(15, 23, 42, 0.62);
  border: 1px solid rgba(148, 163, 184, 0.2);
  text-align: center;
}

.stat strong {
  display: block;
  font-size: 2rem;
  color: var(--accent);
}

.stat span {
  color: var(--muted);
}

.histogram {
  display: grid;
  gap: 0.6rem;
}

.hist-row {
  display: grid;
  grid-template-columns: 2rem 1fr;
  align-items: center;
  gap: 0.75rem;
}

.hist-bar {
  min-height: 1.8rem;
  border-radius: 999px;
  background: rgba(148, 163, 184, 0.12);
  overflow: hidden;
}

.hist-bar i {
  display: inline-flex;
  align-items: center;
  justify-content: flex-end;
  min-width: 2rem;
  height: 100%;
  padding-right: 0.6rem;
  background: var(--accent);
  color: #082f49;
  font-style: normal;
  font-weight: 800;
}

.panel {
  margin-top: 2rem;
  padding: 1.6rem;
  border-radius: 20px;
  background: rgba(15, 23, 42, 0.55);
  border: 1px solid rgba(148, 163, 184, 0.22);
}

.panel.danger {
  border-color: rgba(251, 113, 133, 0.35);
}

@media (max-width: 640px) {
  body {
    padding: 1rem;
  }

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

  .nav {
    justify-content: flex-start;
  }

  .card {
    padding: 1.5rem;
    border-radius: 18px;
  }

  .game-actions {
    flex-direction: column;
  }

  .button {
    width: 100%;
  }

  .key {
    min-width: 1.75rem;
    min-height: 2.4rem;
    font-size: 0.85rem;
  }

  .key.wide {
    min-width: 3.8rem;
  }
}