:root {
    --primary: #d35400;
    --side-grad: linear-gradient(135deg, #d35400, #8e2b1a);
    --gold: #ffd966;
    --border: #cbd5e1;
}

* { box-sizing: border-box; }
body { margin: 0; padding: 20px; font-family: 'Inter', sans-serif; background: #fdf2e9; display: flex; justify-content: center; min-height: 100vh; }
.main-container { width: 100%; max-width: 1100px; }
.glass-card { background: #fff; border-radius: 20px; display: flex; box-shadow: 0 25px 50px rgba(0,0,0,0.1); overflow: hidden; flex-direction: row; }

/* SIDEBAR */
.sidebar { flex: 0.8; background: var(--side-grad); color: #fff; padding: 35px; }
.sidebar h1 { font-size: 1.6rem; color: #fff; margin: 15px 0; line-height: 1.3; }
.brand { color: var(--gold); font-size: 0.8rem; font-weight: 800; }
.intro-text { font-size: 0.85rem; line-height: 1.6; opacity: 0.9; margin-bottom: 12px; text-align: justify; }

/* FORM SECTION */
.form-section { flex: 1.2; padding: 40px; background: #fff; }
.form-title { color: var(--primary); font-size: 1.4rem; font-weight: 800; margin-bottom: 25px; border-left: 5px solid var(--primary); padding-left: 15px; }
.input-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.input-group label { display: block; font-size: 0.85rem; font-weight: 700; color: #444; margin-bottom: 8px; }
input, select { width: 100%; padding: 12px; border: 1.5px solid var(--border); border-radius: 8px; font-size: 0.9rem; }

/* MEMBERS SECTION */
.mem-header { display: flex; justify-content: space-between; align-items: center; margin-top: 30px; margin-bottom: 15px; }
.add-btn-orange { background: #ff9800; color: #fff; border: none; padding: 10px 18px; border-radius: 8px; font-weight: 700; cursor: pointer; }
.member-row { display: grid; grid-template-columns: 2fr 1fr 1fr auto; gap: 10px; background: #f9fafb; padding: 15px; border-radius: 10px; margin-bottom: 10px; border: 1px solid #eee; }

/* PREMIUM FOOTER SUMMARY */
.summary-footer { margin-top: 35px; background: #f8fafc; padding: 25px; border-radius: 15px; border: 1px solid #e2e8f0; }
.total-row { display: flex; justify-content: space-between; align-items: center; margin-bottom: 25px; padding-bottom: 15px; border-bottom: 2px dashed #cbd5e1; }
.total-item { font-size: 1.1rem; font-weight: 700; color: #444; }
.total-item.highlight { font-size: 1.4rem; color: var(--primary); }
.total-item span { color: var(--primary); margin-left: 5px; }

/* CHECKBOX & SPACING */
.confirm-box { margin-bottom: 25px; }
.checkbox-container { display: flex; align-items: center; gap: 10px; cursor: pointer; font-size: 0.9rem; font-weight: 600; color: #333; }
.checkmark { min-width: 20px; height: 20px; border: 2px solid #ccc; border-radius: 5px; position: relative; }
.checkbox-container input { display: none; }
.checkbox-container input:checked + .checkmark { background: var(--primary); border-color: var(--primary); }

.pay-btn { width: 100%; padding: 18px; background: var(--primary); color: #fff; border: none; border-radius: 12px; font-weight: 800; font-size: 1.1rem; cursor: pointer; transition: 0.3s; }
.pay-btn:hover { background: #b54900; box-shadow: 0 10px 20px rgba(211,84,0,0.2); }

/* RESPONSIVE DESIGN */
@media (max-width: 850px) {
    .glass-card { flex-direction: column; }
    .sidebar { flex: none; width: 100%; }
    .form-section { flex: none; width: 100%; padding: 25px; }
    .input-grid { grid-template-columns: 1fr; }
    .member-row { grid-template-columns: 1fr; }
    .total-row { flex-direction: column; gap: 10px; text-align: center; }
}

.err-msg { color: #e11d48; font-size: 11px; display: none; margin-top: 5px; font-weight: 600; }
.hint-box { background: #fff8f0; border: 1px dashed var(--primary); padding: 12px; margin-top: 10px; border-radius: 8px; font-size: 0.85rem; color: var(--primary); font-weight: 600; display: none; }