:root {
  --sky: #1f6feb; --sky-dark: #1554b8; --sun: #f5b301; --ink: #16202c; --muted: #5d6878; --line: #e1e7ef;
  --card: #fff; --bg: #f3f7fd; --ok: #1a7f4b; --ok-bg: #e7f6ee; --bad: #b42318; --bad-bg: #fdecea;
  --warn-bg: #fff4d6; --warn: #8a6100;
}
@media (prefers-color-scheme: dark) {
  :root { --ink: #e6ebf2; --muted: #9aa6b6; --line: #2a3442; --card: #171e28; --bg: #0f141b;
          --ok-bg: #16301f; --ok: #4cc38a; --bad-bg: #3a1d1b; --bad: #ff8b7e; --warn-bg: #3a2f10; --warn: #f2c94c; }
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body { font: 17px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; color: var(--ink); background: var(--bg);
       min-height: 100vh; display: flex; flex-direction: column; }
a { color: var(--sky); }
.top { display: flex; justify-content: space-between; align-items: center; padding: 14px 20px;
       background: linear-gradient(90deg, var(--sky-dark), var(--sky)); color: #fff; }
.brand { color: #fff; text-decoration: none; font-weight: 800; font-size: 19px; display: flex; align-items: center; gap: 10px; }
.sun { width: 20px; height: 20px; border-radius: 50%; background: var(--sun); box-shadow: 0 0 0 5px rgba(245,179,1,.3); }
.link-btn { background: rgba(255,255,255,.18); color: #fff; border: 0; border-radius: 8px; padding: 8px 14px; font: inherit; font-weight: 600; cursor: pointer; }
main { width: 100%; max-width: 920px; margin: 0 auto; padding: 24px 16px 40px; flex: 1; }
footer { text-align: center; color: var(--muted); font-size: 14px; padding: 16px; }
h1 { font-size: 30px; line-height: 1.2; margin: 0 0 6px; }
.sub { color: var(--muted); margin: 0 0 16px; }
.big { font-size: 22px; margin: 4px 0 8px; }
.muted { color: var(--muted); } .small { font-size: 14px; }
.card { background: var(--card); border-radius: 18px; padding: 24px; box-shadow: 0 6px 24px rgba(20,60,120,.08); margin-bottom: 18px; }
.narrow { max-width: 460px; margin: 4vh auto 18px; }
.center { text-align: center; }
.stack { display: grid; gap: 14px; margin: 18px 0; text-align: left; }
label { display: block; font-weight: 600; font-size: 15px; color: var(--muted); }
input { display: block; width: 100%; margin-top: 6px; font: 500 19px/1.2 system-ui, sans-serif; color: var(--ink); padding: 13px 14px;
        border: 2px solid var(--line); border-radius: 12px; background: var(--bg); }
input:focus { outline: none; border-color: var(--sky); }
.code-input { font: 800 30px/1 ui-monospace, Menlo, monospace; letter-spacing: 8px; text-align: center; }
.btn { display: inline-block; font: 700 18px/1 system-ui, sans-serif; padding: 16px 22px; border-radius: 12px; border: 0;
       text-decoration: none; text-align: center; cursor: pointer; }
.btn.primary { background: var(--sky); color: #fff; } .btn.primary:hover { background: var(--sky-dark); }
.btn.ghost { background: transparent; color: var(--muted); }
.btn.wide { display: block; width: 100%; }
.btn:disabled { opacity: .6; }
.flash { border-radius: 12px; padding: 12px 16px; margin-bottom: 14px; background: var(--ok-bg); }
.flash.error { background: var(--bad-bg); color: var(--bad); font-weight: 600; }
.flash.ok { background: var(--ok-bg); color: var(--ok); font-weight: 600; }
.problems li { margin-bottom: 6px; }

.hello { display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap; margin-bottom: 16px; }
.balance { background: linear-gradient(160deg, var(--sky), var(--sky-dark)); color: #fff; border-radius: 18px; padding: 14px 26px;
           text-align: center; min-width: 190px; }
.balance span { display: block; font-size: 15px; opacity: .85; }
.balance strong { display: block; font-size: 44px; line-height: 1.05; }
.balance em { display: block; font-style: normal; font-size: 13px; background: rgba(255,255,255,.18); border-radius: 99px; padding: 2px 10px; margin-top: 4px; }
.notice { border-radius: 12px; padding: 12px 16px; margin-bottom: 10px; background: var(--warn-bg); }
.notice.declined { background: var(--bad-bg); } .notice.accepted { background: var(--ok-bg); }
.tabs { display: flex; gap: 6px; background: var(--line); padding: 5px; border-radius: 14px; margin: 14px 0 18px; }
.tabs a { flex: 1; text-align: center; padding: 11px 6px; border-radius: 10px; color: var(--muted); font-weight: 700; text-decoration: none; font-size: 16px; }
.tabs a.on { background: var(--card); color: var(--ink); box-shadow: 0 2px 8px rgba(20,60,120,.12); }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 14px; }
.reward { background: var(--card); border-radius: 16px; padding: 18px; display: flex; flex-direction: column; gap: 6px;
          box-shadow: 0 4px 18px rgba(20,60,120,.07); border: 2px solid transparent; }
.reward.ok { border-color: rgba(31,111,235,.25); }
.reward.short, .reward.out { opacity: .8; }
.r-name { font-size: 20px; font-weight: 800; } .r-desc { color: var(--muted); font-size: 15px; }
.r-cost { font-weight: 700; color: var(--sky); } .r-how { font-size: 14px; color: var(--muted); margin-bottom: 6px; }
.reward .btn, .r-status { margin-top: auto; } .r-status { color: var(--muted); font-weight: 600; }
.r-left { color: var(--warn); font-size: 14px; font-weight: 600; text-align: center; }
.meter { height: 8px; background: var(--line); border-radius: 99px; overflow: hidden; }
.meter span { display: block; height: 100%; background: var(--sun); }
.list { list-style: none; margin: 0; padding: 0; }
.list li { padding: 12px 0; border-bottom: 1px solid var(--line); }
.list li:last-child { border-bottom: 0; }
.row { display: flex; justify-content: space-between; align-items: center; gap: 12px; }
.info { color: var(--muted); font-size: 14px; margin-top: 6px; background: var(--bg); border-radius: 10px; padding: 8px 12px; }
.pill { font-size: 13px; font-weight: 700; padding: 4px 12px; border-radius: 99px; white-space: nowrap; }
.pill.ok { background: var(--ok-bg); color: var(--ok); } .pill.wait { background: var(--warn-bg); color: var(--warn); }
.pill.ready { background: #e6efff; color: var(--sky-dark); } .pill.off { background: var(--line); color: var(--muted); }
.plus { color: var(--ok); } .minus { color: var(--bad); }
.how { background: var(--bg); border-radius: 12px; padding: 14px 16px; text-align: left; margin: 10px 0 6px; font-size: 16px; }
.instr { margin-top: 8px; color: var(--muted); }
@media (max-width: 520px) { h1 { font-size: 26px; } .balance { width: 100%; } .tabs a { font-size: 14px; } }