.skl-root {
    --skl-bg: #f7f8fa;
    --skl-card: #ffffff;
    --skl-border: #e5e7eb;
    --skl-text: #1f2937;
    --skl-muted: #6b7280;
    --skl-accent: #3f7d5c;
    --skl-accent-hover: #34684b;
    --skl-danger: #b91c1c;
    --skl-radius: 12px;
    max-width: 640px;
    margin: 0 auto;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    color: var(--skl-text);
    line-height: 1.5;
}
.skl-root * { box-sizing: border-box; }

.skl-card {
    background: var(--skl-card);
    border: 1px solid var(--skl-border);
    border-radius: var(--skl-radius);
    padding: 20px;
    margin-bottom: 16px;
}
.skl-title { font-size: 22px; margin: 0 0 6px; font-weight: 600; }
.skl-sub { color: var(--skl-muted); font-size: 14px; margin: 0 0 18px; }
.skl-hint { color: var(--skl-muted); font-size: 13px; margin-top: 10px; }

.skl-label { display: block; font-size: 14px; margin-bottom: 6px; color: var(--skl-muted); }
.skl-input {
    width: 100%;
    padding: 11px 13px;
    font-size: 16px;
    border: 1px solid var(--skl-border);
    border-radius: 8px;
    background: #fff;
    color: var(--skl-text);
    transition: border-color .15s;
}
.skl-input:focus { outline: none; border-color: var(--skl-accent); }
.skl-row { margin-bottom: 14px; }

.skl-btn {
    display: inline-block;
    padding: 12px 18px;
    font-size: 16px;
    font-weight: 500;
    border: 0;
    border-radius: 8px;
    background: var(--skl-accent);
    color: #fff;
    cursor: pointer;
    transition: background .15s;
    text-decoration: none;
    text-align: center;
}
.skl-btn:hover { background: var(--skl-accent-hover); }
.skl-btn:disabled { opacity: .5; cursor: default; }
.skl-btn-secondary {
    background: transparent;
    color: var(--skl-accent);
    border: 1px solid var(--skl-border);
}
.skl-btn-secondary:hover { background: #f3f4f6; }
.skl-btn-full { width: 100%; }
.skl-btn-danger { background: transparent; color: var(--skl-danger); border: 0; padding: 4px 8px; font-size: 13px; }
.skl-btn-danger:hover { text-decoration: underline; background: transparent; }

.skl-link-box {
    display: flex;
    gap: 8px;
    align-items: center;
    background: #f3f4f6;
    padding: 10px 12px;
    border-radius: 8px;
    font-size: 13px;
    word-break: break-all;
    margin: 10px 0;
}
.skl-link-box span { flex: 1; }

.skl-expense {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 12px;
    padding: 12px 0;
    border-bottom: 1px solid var(--skl-border);
}
.skl-expense:last-child { border-bottom: 0; }
.skl-expense-main { flex: 1; min-width: 0; }
.skl-expense-title { font-weight: 500; word-break: break-word; }
.skl-expense-meta { font-size: 13px; color: var(--skl-muted); margin-top: 2px; }
.skl-expense-amount { font-weight: 600; white-space: nowrap; }
.skl-expense-actions { display: flex; flex-direction: column; align-items: flex-end; }

.skl-balance {
    display: flex;
    justify-content: space-between;
    padding: 8px 0;
    font-size: 15px;
    border-bottom: 1px dashed var(--skl-border);
}
.skl-balance:last-child { border-bottom: 0; }
.skl-balance-name { color: var(--skl-text); }
.skl-balance-pos { color: var(--skl-accent); font-weight: 500; }
.skl-balance-neg { color: var(--skl-danger); font-weight: 500; }
.skl-balance-zero { color: var(--skl-muted); }

.skl-settle {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 0;
    border-bottom: 1px solid var(--skl-border);
    font-size: 15px;
}
.skl-settle:last-child { border-bottom: 0; }
.skl-arrow { color: var(--skl-muted); }
.skl-settle-amount { margin-left: auto; font-weight: 600; }

.skl-error { color: var(--skl-danger); font-size: 14px; margin-top: 10px; }
.skl-ok { color: var(--skl-accent); font-size: 14px; margin-top: 10px; }
.skl-loading { text-align: center; padding: 40px 0; color: var(--skl-muted); }

.skl-participants { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 6px; }
.skl-chip {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 10px;
    background: #f3f4f6;
    border-radius: 20px;
    font-size: 14px;
    cursor: pointer;
    border: 1px solid transparent;
    user-select: none;
}
.skl-chip input { margin: 0; }
.skl-chip.skl-chip-on { background: #e8f0eb; border-color: var(--skl-accent); }

.skl-section-head {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 10px;
}
.skl-section-head h3 { font-size: 16px; margin: 0; font-weight: 600; }
.skl-section-head .skl-muted { font-size: 13px; color: var(--skl-muted); }

.skl-badge-days {
    display: inline-block;
    font-size: 12px;
    color: var(--skl-muted);
    background: #f3f4f6;
    padding: 3px 8px;
    border-radius: 12px;
}

@media (max-width: 480px) {
    .skl-card { padding: 16px; }
    .skl-title { font-size: 20px; }
}