:root {
  --violet: #6366f1;
  --violet-dark: #4f46e5;
  --violet-soft: #eef2ff;
  --ink: #0f172a;
  --muted: #64748b;
  --line: #e2e8f0;
  --ok: #059669;
  --bg: #f8fafc;
  --card: #ffffff;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(15, 23, 42, 0.06);
  --font: "DM Sans", system-ui, -apple-system, sans-serif;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: var(--font);
  color: var(--ink);
  background:
    radial-gradient(1200px 500px at 10% -10%, #e0e7ff 0%, transparent 55%),
    radial-gradient(900px 400px at 100% 0%, #fce7f3 0%, transparent 45%),
    var(--bg);
  min-height: 100vh;
}

a { color: var(--violet-dark); text-decoration: none; }
button, input { font: inherit; }

.shell {
  width: min(820px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 2rem 0 4rem;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.75rem;
}
.brand {
  display: flex;
  align-items: center;
  gap: .75rem;
}
.brand img { height: 28px; width: auto; }
.brand span {
  font-weight: 700;
  letter-spacing: -0.02em;
  font-size: 1.05rem;
}
.user-chip {
  display: flex;
  align-items: center;
  gap: .65rem;
  color: var(--muted);
  font-size: .9rem;
}
.user-chip button {
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 999px;
  padding: .35rem .8rem;
  cursor: pointer;
  color: var(--ink);
}
.user-chip button:hover { border-color: var(--violet); color: var(--violet-dark); }

h1 {
  margin: 0 0 .35rem;
  font-size: clamp(1.6rem, 3vw, 2.1rem);
  letter-spacing: -0.03em;
  line-height: 1.15;
}
.lead {
  margin: 0 0 1.5rem;
  color: var(--muted);
  font-size: 1rem;
  line-height: 1.5;
}

.steps {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  margin-bottom: 1.5rem;
}
.step {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  border-radius: 999px;
  padding: .45rem .9rem;
  font-size: .85rem;
  font-weight: 600;
  border: 1px solid var(--line);
  background: #fff;
  color: var(--muted);
}
.step.active {
  background: linear-gradient(135deg, var(--violet), #8b5cf6);
  border-color: transparent;
  color: #fff;
}
.step .n {
  width: 1.25rem;
  height: 1.25rem;
  border-radius: 999px;
  display: grid;
  place-items: center;
  font-size: .75rem;
  background: rgba(255,255,255,.2);
}
.step:not(.active) .n {
  background: var(--violet-soft);
  color: var(--violet-dark);
}

.balance-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 1.15rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--card);
  box-shadow: var(--shadow);
  margin-bottom: 1.25rem;
}
.balance-card .label { color: var(--muted); font-size: .85rem; }
.balance-card .value {
  font-size: 1.55rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}
.balance-card .value.low { color: #dc2626; }
.balance-card .hint { color: var(--muted); font-size: .85rem; text-align: right; }

.packs { display: grid; gap: .75rem; }

.pack {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 1rem;
  align-items: center;
  padding: 1rem 1.15rem;
  border: 1.5px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, #fff 0%, #fafafa 100%);
  cursor: pointer;
  transition: border-color .15s ease, box-shadow .15s ease, transform .15s ease;
}
.pack:hover {
  border-color: #c7d2fe;
  transform: translateY(-1px);
}
.pack.selected {
  border-color: var(--violet);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, .12);
  background: linear-gradient(180deg, #fff 0%, var(--violet-soft) 100%);
}
.pack input { accent-color: var(--violet); width: 1.1rem; height: 1.1rem; }
.pack h3 {
  margin: 0 0 .25rem;
  font-size: 1rem;
  letter-spacing: -0.01em;
}
.pack p {
  margin: 0;
  color: var(--muted);
  font-size: .88rem;
  line-height: 1.45;
}
.pack .hl { color: var(--ok); font-weight: 600; }
.pack .price {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  white-space: nowrap;
}
.pack .badge {
  display: inline-block;
  margin-left: .4rem;
  font-size: .7rem;
  font-weight: 700;
  color: #fff;
  background: var(--ok);
  border-radius: 999px;
  padding: .15rem .45rem;
  vertical-align: middle;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  margin-top: 1.35rem;
  align-items: center;
}
.btn {
  appearance: none;
  border: none;
  border-radius: 12px;
  padding: .9rem 1.35rem;
  font-weight: 700;
  cursor: pointer;
  transition: transform .12s ease, opacity .12s ease;
}
.btn:disabled { opacity: .55; cursor: not-allowed; }
.btn:not(:disabled):hover { transform: translateY(-1px); }
.btn-primary {
  background: linear-gradient(135deg, var(--violet), #8b5cf6);
  color: #fff;
  box-shadow: 0 8px 20px rgba(99, 102, 241, .28);
}
.btn-ghost {
  background: #fff;
  border: 1px solid var(--line);
  color: var(--ink);
}

.auth-panel, .overlay-panel {
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 4px);
  background: var(--card);
  box-shadow: var(--shadow);
  padding: 1.5rem;
}
.auth-panel h2 { margin: 0 0 .35rem; font-size: 1.35rem; }
.auth-panel .lead { margin-bottom: 1.1rem; }
.field { margin-bottom: .9rem; }
.field label {
  display: block;
  font-size: .85rem;
  font-weight: 600;
  margin-bottom: .35rem;
}
.field input {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: .8rem .95rem;
  background: #fff;
}
.field input:focus {
  outline: 2px solid rgba(99, 102, 241, .35);
  border-color: var(--violet);
}
.msg {
  margin: .75rem 0 0;
  font-size: .9rem;
  color: var(--muted);
}
.msg.error { color: #dc2626; }
.msg.ok { color: var(--ok); }

.overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, .45);
  display: grid;
  place-items: center;
  padding: 1rem;
  z-index: 50;
}
.overlay[hidden] { display: none !important; }
.overlay-panel { width: min(420px, 100%); text-align: center; }
.overlay-panel h2 { margin: 0 0 .5rem; }
.overlay-panel p { color: var(--muted); margin: 0 0 1.25rem; line-height: 1.5; }

.hidden { display: none !important; }
.loading {
  color: var(--muted);
  padding: 2rem 0;
  text-align: center;
}

@media (max-width: 640px) {
  .shell { width: min(100% - 1.25rem, 820px); padding-top: 1.25rem; }
  .pack {
    grid-template-columns: auto 1fr;
    grid-template-rows: auto auto;
  }
  .pack .price {
    grid-column: 2;
    justify-self: start;
    margin-top: .15rem;
  }
  .balance-card { flex-direction: column; align-items: flex-start; }
  .balance-card .hint { text-align: left; }
}