:root{
  --bg:#f4f5fb;
  --card:#ffffff;
  --ink:#171a2c;
  --muted:#6b7194;
  --line:#e7e9f4;
  --brand1:#5b5ff0;
  --brand2:#9333ea;
  --brand-grad:linear-gradient(135deg,#5b5ff0 0%,#9333ea 100%);
  --good:#0d9f6e;
  --good-bg:#e3f7ef;
  --warn:#c2410c;
  --warn-bg:#fdeee2;
  --shadow:0 6px 24px rgba(23,26,44,.07);
  --shadow-lg:0 12px 40px rgba(91,95,240,.28);
  --radius:18px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%}
body{
  font-family:'Heebo',system-ui,-apple-system,'Segoe UI',sans-serif;
  background:
    radial-gradient(60vw 40vh at 85% -10%, rgba(147,51,234,.10), transparent 60%),
    radial-gradient(70vw 50vh at -20% 10%, rgba(91,95,240,.10), transparent 60%),
    var(--bg);
  color:var(--ink);
  min-height:100vh;
  min-height:100dvh;
}
.hidden{display:none!important}

/* ---------- top bar ---------- */
#topbar{
  position:sticky;top:0;z-index:20;
  display:flex;align-items:center;gap:12px;
  padding:calc(14px + env(safe-area-inset-top)) 18px 16px;
  background:var(--brand-grad);
  color:#fff;
  box-shadow:0 4px 20px rgba(91,95,240,.35);
}
#viewTitle{font-size:21px;font-weight:800;flex:1;text-align:center;letter-spacing:.2px}
.icon-btn{
  width:38px;height:38px;border:none;border-radius:12px;
  background:rgba(255,255,255,.16);color:#fff;font-size:19px;font-weight:700;
  cursor:pointer;display:flex;align-items:center;justify-content:center;
  transition:background .15s;
}
.icon-btn:active{background:rgba(255,255,255,.3)}

/* ---------- layout ---------- */
#app{max-width:520px;margin:0 auto;padding:20px 16px 120px}
h3{font-size:17px;font-weight:800;margin:22px 4px 10px}

/* ---------- cards ---------- */
.card{
  background:var(--card);border-radius:var(--radius);
  padding:16px 18px;margin-bottom:12px;
  box-shadow:var(--shadow);
  border:1px solid rgba(231,233,244,.7);
}
.row{display:flex;align-items:center;gap:10px}
.grow{flex:1;min-width:0}
.big{font-size:17px;font-weight:700}
.amt{font-size:18px;font-weight:800;color:var(--brand1);white-space:nowrap}
.muted{color:var(--muted);font-size:13px;line-height:1.5}
.sub{color:var(--muted);font-size:12.5px;margin-top:3px}
.footer-note{text-align:center;color:var(--muted);font-size:12px;margin-top:28px}

/* ---------- trip cards ---------- */
[data-open]{cursor:pointer;transition:transform .12s,box-shadow .12s}
[data-open]:active{transform:scale(.985)}

/* ---------- tabs ---------- */
.tabs{
  display:flex;background:#e9ebf7;border-radius:14px;padding:4px;
  margin-bottom:16px;gap:4px;
}
.tabs button{
  flex:1;border:none;background:transparent;padding:9px 0;
  border-radius:11px;font-family:inherit;font-size:14.5px;font-weight:600;
  color:var(--muted);cursor:pointer;transition:all .15s;
}
.tabs button.active{background:#fff;color:var(--ink);box-shadow:0 2px 8px rgba(23,26,44,.1)}

/* ---------- expenses ---------- */
.expense{
  display:flex;align-items:center;gap:12px;
  background:var(--card);border-radius:var(--radius);
  padding:14px 16px;margin-bottom:10px;
  box-shadow:var(--shadow);border:1px solid rgba(231,233,244,.7);
  border-right:4px solid var(--good);
  cursor:pointer;transition:transform .12s;
}
.expense:active{transform:scale(.985)}
.expense.pending{border-right-color:#f0a13c}
.chip{
  display:inline-block;font-size:11.5px;font-weight:700;
  padding:3px 10px;border-radius:999px;
}
.chip.paid{background:var(--good-bg);color:var(--good)}
.chip.unpaid{background:var(--warn-bg);color:var(--warn)}

/* ---------- balances ---------- */
.total-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-bottom:4px}
.total-grid .big{font-size:20px;margin-top:4px}
.pos{color:var(--good)}
.neg{color:#dc2626}
.settle{
  display:flex;align-items:center;gap:10px;
  background:var(--card);border-radius:var(--radius);
  padding:13px 16px;margin-bottom:10px;box-shadow:var(--shadow);
  font-size:15px;font-weight:600;
}
.settle .arrow{color:var(--brand1);font-weight:800}

/* ---------- forms ---------- */
label{display:block;font-size:13.5px;font-weight:600;color:var(--muted);margin:16px 4px 6px}
input[type=text],input[type=number],input[type=date],select{
  width:100%;padding:13px 14px;font-size:16px;font-family:inherit;
  border:1.5px solid var(--line);border-radius:14px;background:#fff;color:var(--ink);
  outline:none;transition:border-color .15s,box-shadow .15s;
  -webkit-appearance:none;appearance:none;
}
input:focus,select:focus{border-color:var(--brand1);box-shadow:0 0 0 3px rgba(91,95,240,.14)}
select{background-image:url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%236b7194' stroke-width='2.5'%3e%3cpath d='M6 9l6 6 6-6'/%3e%3c/svg%3e");background-repeat:no-repeat;background-position:left 14px center;background-size:16px;padding-left:40px}
.checkline{
  display:flex;align-items:center;gap:10px;
  font-size:15px;font-weight:500;color:var(--ink);
  margin:4px 0;padding:10px 12px;background:#fff;
  border:1.5px solid var(--line);border-radius:12px;
}
.checkline input{width:19px;height:19px;accent-color:var(--brand1)}

/* ---------- buttons ---------- */
button{font-family:inherit}
.primary{
  width:100%;border:none;cursor:pointer;
  background:var(--brand-grad);color:#fff;
  font-size:16.5px;font-weight:700;
  padding:15px;border-radius:16px;
  box-shadow:var(--shadow-lg);
  transition:transform .12s,box-shadow .12s;
}
.primary:active{transform:translateY(1px)}
.ghost{
  border:1.5px solid var(--line);background:#fff;color:var(--ink);
  font-size:14.5px;font-weight:600;padding:11px 18px;border-radius:13px;cursor:pointer;
  transition:border-color .15s;
}
.ghost:active{border-color:var(--brand1)}
.settle .ghost{padding:7px 14px;font-size:13px;color:var(--brand1);border-color:#dcdff9}

/* ---------- FAB ---------- */
#fab{
  position:fixed;bottom:calc(22px + env(safe-area-inset-bottom));left:50%;transform:translateX(-50%);
  z-index:30;border:none;cursor:pointer;
  display:flex;align-items:center;gap:9px;
  background:var(--brand-grad);color:#fff;
  font-size:17px;font-weight:800;
  padding:16px 28px;border-radius:999px;
  box-shadow:0 10px 32px rgba(91,95,240,.45);
  transition:transform .12s;
}
#fab:active{transform:translateX(-50%) scale(.95)}
.fab-plus{font-size:22px;font-weight:800;line-height:1}

/* ---------- menu sheet ---------- */
.sheet{
  position:fixed;top:calc(64px + env(safe-area-inset-top));left:14px;z-index:40;
  background:#fff;border-radius:16px;box-shadow:0 14px 44px rgba(23,26,44,.2);
  padding:8px;min-width:210px;border:1px solid var(--line);
}
.sheet button{
  display:block;width:100%;text-align:right;border:none;background:none;
  padding:12px 14px;font-size:14.5px;font-weight:600;color:var(--ink);
  border-radius:10px;cursor:pointer;
}
.sheet button:active{background:var(--bg)}

/* ---------- login ---------- */
.login-wrap{
  position:relative;
  min-height:calc(100dvh - 90px);
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  text-align:center;padding:20px;
}
.login-logo{
  font-size:52px;font-weight:800;letter-spacing:-.5px;
  background:var(--brand-grad);
  -webkit-background-clip:text;background-clip:text;color:transparent;
  margin-bottom:10px;
}
.login-sub{color:var(--muted);font-size:15px;margin-bottom:34px;max-width:280px;line-height:1.6}
.login-form{display:flex;flex-direction:column;gap:12px;width:min(320px,86vw)}
.login-input{
  width:100%;border:1.5px solid var(--line);border-radius:16px;
  padding:15px 18px;font-size:16px;font-family:inherit;color:var(--ink);
  background:#fff;box-shadow:var(--shadow);outline:none;
  transition:border-color .15s, box-shadow .15s;text-align:left;
}
.login-input:focus{border-color:var(--brand1);box-shadow:0 0 0 4px rgba(91,95,240,.14)}
.login-btn{
  width:100%;border:none;border-radius:16px;padding:15px 18px;
  background:var(--brand-grad);color:#fff;
  font-size:17px;font-weight:800;font-family:inherit;cursor:pointer;
  box-shadow:var(--shadow-lg);transition:transform .12s;
}
.login-btn:active{transform:scale(.97)}
.login-btn:disabled{opacity:.7}
.login-err{color:var(--warn);font-size:13.5px;font-weight:600}
.sync-note{font-size:12px;color:var(--muted);text-align:center;margin:14px 0 0}