:root {
    --navy: #0f172a;
    --gold: #b8924e;
    --white: #ffffff;
    --bg: #f8fafc;
    --rose: #fb7185;
    --emerald: #10b981;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: 'Plus Jakarta Sans', sans-serif; background: var(--bg); color: var(--navy); }

.navbar { display: flex; justify-content: space-between; align-items: center; padding: 1.5rem 8%; background: white; border-bottom: 1px solid #e2e8f0; }
.logo { font-size: 1.5rem; font-weight: 800; }
.logo span { color: var(--gold); }
.btn-back { font-size: 0.7rem; font-weight: 800; color: #ef4444; text-decoration: none; border: 1px solid #fee2e2; padding: 8px 16px; border-radius: 8px; }

.card-container { max-width: 1200px; margin: 0 auto; padding: 4rem 5%; }
.step-header { text-align: center; margin-bottom: 3rem; }
.step-badge { font-size: 0.7rem; font-weight: 800; color: var(--gold); letter-spacing: 2px; }
h1 { font-size: 2.8rem; margin: 10px 0; }
.text-gradient { background: linear-gradient(90deg, var(--navy), var(--gold)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }

/* GRID */
.selection-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 2rem; margin-bottom: 3rem; }

.card-option { background: white; border: 2px solid #e2e8f0; border-radius: 28px; padding: 1.5rem; cursor: pointer; transition: 0.4s; }
.card-option.active { border-color: var(--gold); background: #fdfaf3; transform: translateY(-10px); box-shadow: 0 20px 40px rgba(184, 146, 78, 0.2); }

/* VISUAL KARTU */
.card-preview { height: 180px; border-radius: 20px; padding: 1.5rem; color: white; margin-bottom: 1.5rem; position: relative; overflow: hidden; display: flex; flex-direction: column; justify-content: space-between; }
.card-chip { width: 45px; height: 35px; border-radius: 6px; }
.card-chip.silver { background: #bdc3c7; }
.card-chip.gold { background: linear-gradient(135deg, #facc15, #b8924e); }

/* GRADIENT VARIAN */
.platinum { background: linear-gradient(135deg, #334155, #0f172a); }
.gold-card { background: linear-gradient(135deg, #fbbf24, #b8924e); }
.rose-gold { background: linear-gradient(135deg, #fda4af, #e11d48); }
.black { background: radial-gradient(circle at top right, #444, #000); }
.emerald { background: linear-gradient(135deg, #059669, #064e3b); }
.diamond { background: linear-gradient(135deg, #e2e8f0, #94a3b8); border: 1px solid rgba(255,255,255,0.5); }

/* ANIMASI KILAU DIAMOND & EMERALD */
.diamond::before, .emerald::before {
    content: ''; position: absolute; top: -100%; left: -100%; width: 300%; height: 300%;
    background: linear-gradient(45deg, transparent, rgba(255,255,255,0.3), transparent);
    transform: rotate(45deg); animation: shine 4s infinite;
}
@keyframes shine { 0% { transform: translateX(-100%) rotate(45deg); } 100% { transform: translateX(100%) rotate(45deg); } }

.card-brand { font-weight: 800; font-size: 0.8rem; letter-spacing: 1px; }
.card-number { letter-spacing: 3px; font-size: 1rem; opacity: 0.8; }

.option-details h3 { font-size: 1.2rem; margin-bottom: 8px; }
.option-details p { font-size: 0.85rem; color: #64748b; margin-bottom: 15px; }
.price-tag { font-weight: 800; background: #f1f5f9; padding: 5px 12px; border-radius: 8px; font-size: 0.8rem; }
.price-tag.special { background: #fef3c7; color: #92400e; }

.btn-primary { background: var(--navy); color: white; border: none; padding: 1.2rem 4rem; border-radius: 15px; font-weight: 800; cursor: pointer; transition: 0.3s; width: 100%; max-width: 400px; }
.btn-primary:hover { background: var(--gold); transform: scale(1.05); }

@media (max-width: 768px) { .selection-grid { grid-template-columns: 1fr; } }