:root {
  --bg: #0f172a;
  --surface: #111827;
  --surface-2: #1f2937;
  --text: #f8fafc;
  --muted: #cbd5e1;
  --accent: #22c55e;
  --accent-2: #16a34a;
  --border: rgba(255, 255, 255, 0.08);
  --danger: #ef4444;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: linear-gradient(180deg, #020617 0%, #0f172a 100%);
  color: var(--text);
}

a { color: #93c5fd; text-decoration: none; }
a:hover { text-decoration: underline; }

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border);
  background: rgba(2, 6, 23, 0.85);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 10;
  flex-wrap: wrap;
}
.topbar h1 { margin: 0; font-size: 1.8rem; }
.topbar p { margin: 0.35rem 0 0; color: var(--muted); }
.topbar nav a {
  background: var(--surface-2);
  border: 1px solid var(--border);
  padding: 0.7rem 1rem;
  border-radius: 999px;
  font-size: 0.9rem;
}

.layout,
.auth-layout {
  display: grid;
  gap: 1.25rem;
  padding: 1.5rem;
}
.layout {
  grid-template-columns: minmax(300px, 420px) 1fr;
  grid-template-rows: auto auto;
}
.layout > .tracker-card {
  grid-row: 1 / 3;
}
.layout > .leaderboard-card {
  grid-row: 1;
  grid-column: 2;
}
.layout > .permille-card {
  grid-row: 2;
  grid-column: 2;
}
.auth-layout {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.layout-full {
  display: grid;
  gap: 1.25rem;
  padding: 1.5rem;
  grid-template-columns: 1fr;
}

@media (max-width: 920px) {
  .layout {
    grid-template-columns: 1fr;
  }
}

.card {
  background: rgba(17, 24, 39, 0.94);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 1.25rem;
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.3);
}

.section-head,
.chart-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}
.chart-header { align-items: flex-start; flex-direction: column; margin-top: 1rem; }

label {
  display: block;
  font-size: 0.95rem;
  margin: 0.8rem 0 0.4rem;
  color: var(--muted);
}

input,
select,
button {
  font: inherit;
}

input,
select {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--surface-2);
  color: var(--text);
  padding: 0.9rem 1rem;
}

button {
  border: 0;
  border-radius: 14px;
  padding: 0.9rem 1.1rem;
  cursor: pointer;
  transition: transform 0.12s ease, opacity 0.12s ease;
}
button:hover { transform: translateY(-1px); }
button:disabled { opacity: 0.55; cursor: not-allowed; transform: none; }

.primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #052e16;
  font-weight: 800;
}
.ghost {
  background: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border);
}
.big-button {
  width: 100%;
  margin-top: 1rem;
  font-size: 1.1rem;
  padding: 1rem 1.2rem;
}

.unit-preview,
.login-callout,
.session-info,
.small-note {
  color: var(--muted);
}
.unit-preview,
.login-callout,
.session-info {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 0.9rem 1rem;
  margin-top: 0.9rem;
}
.login-callout { margin-bottom: 0.8rem; }

.summary-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.8rem;
  margin: 1rem 0;
}
.stat-box {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1rem;
}
.stat-label {
  display: block;
  color: var(--muted);
  font-size: 0.9rem;
  margin-bottom: 0.35rem;
}
.stat-box strong { font-size: 1.5rem; }

.recent-list {
  list-style: none;
  padding: 0;
  margin: 0.8rem 0 0;
  display: grid;
  gap: 0.7rem;
}
.recent-list li {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 0.85rem 0.95rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.45rem 0.75rem;
  border-radius: 999px;
  font-size: 0.85rem;
  border: 1px solid var(--border);
}
.badge.muted { background: rgba(255,255,255,0.04); color: var(--muted); }
.badge.success { background: rgba(34, 197, 94, 0.14); color: #86efac; }

.permille-info {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 0;
}

.user-stats {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1rem;
  margin: 1rem 0;
}

.stats-row {
  display: grid;
  gap: 0.5rem;
}

.stat-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.5rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
}

.stat-item:last-child {
  border-bottom: none;
}

.stat-label {
  color: var(--muted);
  font-size: 0.9rem;
}

.permille-value {
  display: inline-block;
  padding: 0.25rem 0.5rem;
  background: rgba(239, 68, 68, 0.2);
  color: #fca5a5;
  border-radius: 6px;
  font-weight: 600;
}

.table-wrap { overflow-x: auto; }
table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 0.8rem;
}
th, td {
  text-align: left;
  padding: 0.85rem 0.7rem;
  border-bottom: 1px solid var(--border);
}
tbody tr {
  cursor: pointer;
}
tbody tr:hover,
tbody tr.active-row {
  background: rgba(255, 255, 255, 0.05);
}

.form-stack {
  display: grid;
  gap: 0.5rem;
}

.toast {
  position: fixed;
  bottom: 1rem;
  right: 1rem;
  background: #111827;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 0.9rem 1rem;
  box-shadow: 0 10px 30px rgba(0,0,0,0.3);
}
.hidden { display: none; }

.size-buttons {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
  margin-top: 0.5rem;
}

.size-btn {
  padding: 0.85rem 0.75rem;
  background: var(--surface-2);
  color: var(--text);
  border: 2px solid var(--border);
  border-radius: 14px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.12s ease;
}

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

.size-btn.active {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #052e16;
  border-color: var(--accent);
}

@media (max-width: 768px) {
  .topbar {
    padding: 1rem 1.25rem;
  }
  
  .topbar h1 {
    font-size: 1.4rem;
  }
  
  .topbar p {
    display: none;
  }
  
  .layout {
    grid-template-columns: 1fr;
    grid-template-rows: auto;
  }
  
  .layout > .tracker-card,
  .layout > .leaderboard-card,
  .layout > .permille-card {
    grid-column: 1;
    grid-row: auto;
  }
  
  .auth-layout {
    padding: 1rem;
    gap: 1rem;
  }
  
  .card {
    padding: 1rem;
    border-radius: 16px;
  }
  
  .section-head {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.75rem;
  }
  
  .summary-grid {
    grid-template-columns: 1fr;
  }
  
  table {
    font-size: 0.9rem;
  }
  
  th, td {
    padding: 0.6rem 0.5rem;
  }
  
  .size-buttons {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .big-button {
    font-size: 1rem;
    padding: 0.85rem 1rem;
  }
}

@media (max-width: 480px) {
  .topbar nav {
    width: 100%;
  }
  
  .topbar nav a {
    width: 100%;
    text-align: center;
  }
  
  .layout,
  .auth-layout {
    padding: 0.75rem;
    gap: 0.75rem;
  }
  
  .card {
    padding: 0.85rem;
    border-radius: 14px;
  }
  
  label {
    font-size: 0.9rem;
    margin: 0.6rem 0 0.3rem;
  }
  
  input,
  select {
    padding: 0.8rem 0.9rem;
    font-size: 1rem;
  }
  
  button {
    padding: 0.8rem 1rem;
    border-radius: 12px;
  }
  
  .section-head {
    gap: 0.5rem;
  }
  
  .section-head h2 {
    font-size: 1.3rem;
  }
  
  .badge {
    font-size: 0.8rem;
    padding: 0.4rem 0.6rem;
  }
  
  .stat-label {
    font-size: 0.85rem;
  }
  
  .stat-box strong {
    font-size: 1.3rem;
  }
  
  .size-buttons {
    grid-template-columns: repeat(2, 1fr);
    gap: 0.5rem;
  }
  
  .size-btn {
    padding: 0.7rem 0.5rem;
    font-size: 0.85rem;
  }
  
  .big-button {
    font-size: 0.95rem;
    padding: 0.75rem 1rem;
    margin-top: 0.75rem;
  }
  
  table {
    font-size: 0.8rem;
  }
  
  th {
    font-size: 0.75rem;
  }
  
  th, td {
    padding: 0.5rem 0.35rem;
  }
  
  .chart-header h3 {
    font-size: 1.1rem;
  }
  
  .chart-header p {
    display: none;
  }
}