:root {
    --bg: #0a0a0c;
    --card: #131316;
    --border: #2a2a32;
    --pink: #ff00ff;
    --pink-hover: #d000d0;
    --text: #e0e0e0;
    --text-white: #ffffff;
    --muted: #8a8a93;
    --success: #4ade80;
    --success-border: rgba(74, 222, 128, 0.5);
    
    font-family: 'Inter', sans-serif;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--bg);
    color: var(--text);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    -webkit-font-smoothing: antialiased;
}

::selection {
    background-color: var(--pink);
    color: var(--text-white);
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg);
}
::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--pink);
}

/* Layout Classes */
.container {
    max-width: 1152px; /* ~72rem / 6xl */
    margin: 0 auto;
    padding: 0 20px;
    width: 100%;
}

.flex { display: flex; }
.grid { display: grid; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.flex-col { flex-direction: column; }
.gap-2 { gap: 0.5rem; }
.gap-3 { gap: 0.75rem; }
.gap-4 { gap: 1rem; }
.gap-6 { gap: 1.5rem; }
.gap-8 { gap: 2rem; }

/* Header */
.header {
    border-bottom: 1px solid var(--border);
    background-color: rgba(19, 19, 22, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    position: sticky;
    top: 0;
    z-index: 50;
    padding: 1rem 0;
}

.logo-badge {
    width: 2rem;
    height: 2rem;
    border-radius: 0.25rem;
    background: linear-gradient(to bottom right, var(--pink), #9333ea);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: var(--text-white);
}

.brand-name {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text-white);
}

.brand-accent {
    color: var(--pink);
}

.nav-links {
    display: none;
}
@media (min-width: 640px) {
    .nav-links {
        display: flex;
        gap: 1.5rem;
        font-size: 0.875rem;
        font-weight: 500;
        color: var(--muted);
    }
}
.nav-links a {
    text-decoration: none;
    color: inherit;
    transition: color 0.2s ease;
}
.nav-links a:hover {
    color: var(--text-white);
}

/* Main Spacing */
.main-content {
    flex-grow: 1;
    padding: 3rem 0;
    display: flex;
    flex-direction: column;
    gap: 4rem;
}

/* Section Shared */
.section-title {
    font-size: 2.25rem;
    font-weight: 700;
    color: var(--text-white);
    margin-bottom: 1rem;
}
.section-subtitle {
    color: var(--muted);
    font-size: 1.125rem;
}

/* Guide Section */
.guide-card {
    background-color: var(--card);
    border: 1px solid var(--border);
    border-radius: 1rem;
    padding: 2.5rem;
    position: relative;
    overflow: hidden;
    box-shadow: 0 25px 50px -12px rgba(0,0,0,0.5);
}

.glow-decoration {
    position: absolute;
    top: -6rem;
    right: -6rem;
    width: 16rem;
    height: 16rem;
    background-color: rgba(255, 0, 255, 0.15);
    border-radius: 50%;
    filter: blur(60px);
    pointer-events: none;
}

.guide-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
    align-items: center;
    position: relative;
    z-index: 10;
}
@media (min-width: 768px) {
    .guide-grid { grid-template-columns: 1fr 1fr; }
}

.step-card {
    background-color: var(--bg);
    border: 1px solid var(--border);
    border-radius: 0.75rem;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 1rem;
}
@media (min-width: 640px) {
    .step-card {
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
    }
}

.step-label {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--muted);
    margin-bottom: 0.25rem;
    display: block;
}
.step-title {
    font-weight: 500;
    color: var(--text-white);
}

.btn-copy {
    background-color: rgba(255,255,255,0.05);
    color: var(--text-white);
    border: 1px solid var(--border);
    padding: 0.5rem 1rem;
    border-radius: 0.5rem;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.2s ease;
    white-space: nowrap;
}
.btn-copy:hover {
    background-color: rgba(255,255,255,0.1);
}
.btn-copy.accent {
    background-color: rgba(255, 0, 255, 0.1);
    color: var(--pink);
    border-color: rgba(255, 0, 255, 0.3);
    font-weight: 700;
}
.btn-copy.accent:hover {
    background-color: rgba(255, 0, 255, 0.2);
}

.copied-state {
    color: var(--success) !important;
    border-color: var(--success-border) !important;
}

.discount-summary-card {
    display: none;
    background-color: var(--bg);
    border: 1px solid var(--border);
    border-radius: 0.75rem;
    padding: 1.5rem;
    box-shadow: 0 20px 25px -5px rgba(0,0,0,0.3);
    width: 100%;
    max-width: 24rem;
}
@media (min-width: 768px) {
    .discount-summary-card {
        display: block;
        margin: 0 auto;
    }
}

.summary-heading {
    text-align: center;
    color: var(--muted);
    font-size: 0.875rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 1.5rem;
}

.summary-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
}
.summary-row.total {
    margin-bottom: 0;
}
.summary-divider {
    height: 1px;
    background-color: var(--border);
    margin: 1rem 0;
}

/* Calculator Section */
.calc-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
}
@media (min-width: 1024px) {
    .calc-grid { grid-template-columns: 7fr 5fr; }
}

.calc-inputs, .calc-output-wrapper {
    background-color: var(--card);
    border: 1px solid var(--border);
    border-radius: 1rem;
    padding: 2rem;
}

.calc-output-wrapper {
    background-color: var(--bg);
    position: sticky;
    top: 6rem;
    height: fit-content;
}

.input-group { margin-bottom: 2rem; }
.input-label {
    display: block;
    font-size: 0.875rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--muted);
    margin-bottom: 0.75rem;
}

.product-selector {
    display: grid;
    grid-template-columns: 1fr;
    gap: 0.75rem;
}
@media (min-width: 640px) {
    .product-selector { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 1024px) {
    .product-selector { grid-template-columns: repeat(4, 1fr); }
}

.btn-product {
    padding: 1rem;
    border-radius: 0.75rem;
    border: 1px solid var(--border);
    background-color: var(--bg);
    color: var(--muted);
    font-weight: 700;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s ease;
}
.btn-product:hover {
    border-color: #6b7280;
    color: #d1d5db;
}
.btn-product.active {
    border-color: var(--pink);
    background-color: rgba(255,0,255,0.1);
    color: var(--text-white);
    box-shadow: 0 0 15px rgba(255,0,255,0.2);
}

.variant-select {
    width: 100%;
    background-color: var(--bg);
    border: 1px solid var(--border);
    color: var(--text-white);
    border-radius: 0.75rem;
    padding: 1rem;
    font-size: 1rem;
    appearance: none;
    cursor: pointer;
    transition: border-color 0.2s;
    outline: none;
    font-family: inherit;
}
.variant-select:focus {
    border-color: var(--pink);
}

.checkbox-container {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}
.checkbox-label {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem;
    border-radius: 0.75rem;
    border: 1px solid var(--border);
    background-color: var(--bg);
    cursor: pointer;
    transition: border-color 0.2s;
}
.checkbox-label:hover {
    border-color: #4b5563;
}
.checkbox-wrapper {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}
.checkbox-input {
    width: 1.25rem;
    height: 1.25rem;
    accent-color: var(--pink);
    cursor: pointer;
}

.output-title {
    font-size: 1.125rem;
    font-weight: 500;
    color: var(--text-white);
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border);
    margin-bottom: 1.5rem;
}

.output-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}
.original-price-val {
    color: #d1d5db;
    text-decoration: line-through;
}

.final-price-card {
    background-color: var(--card);
    border: 1px solid var(--border);
    border-radius: 0.75rem;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}
.final-price-val {
    font-size: 2.25rem;
    font-weight: 900;
    color: var(--text-white);
}

.btn-buy {
    display: block;
    width: 100%;
    background-color: var(--pink);
    color: var(--text-white);
    text-align: center;
    font-weight: 700;
    padding: 1rem;
    border-radius: 0.75rem;
    text-decoration: none;
    transition: background-color 0.2s;
}
.btn-buy:hover {
    background-color: var(--pink-hover);
}

/* Tier List Section */
.tier-header {
    margin-bottom: 2.5rem;
    text-align: left;
}

.tier-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
}
@media (min-width: 768px) {
    .tier-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 1024px) {
    .tier-grid { grid-template-columns: repeat(4, 1fr); }
}

.tier-card {
    background-color: var(--card);
    border: 1px solid var(--border);
    border-radius: 1rem;
    overflow: hidden;
    transition: border-color 0.3s ease;
}
.tier-card:hover {
    border-color: rgba(255,0,255,0.4);
}

.tier-banner {
    height: 8rem;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
}
.tier-card:nth-child(1) .tier-banner { background: linear-gradient(to bottom right, #1e3a8a, #111827); }
.tier-card:nth-child(2) .tier-banner { background: linear-gradient(to bottom right, #581c87, #111827); }
.tier-card:nth-child(3) .tier-banner { background: linear-gradient(to bottom right, #312e81, #111827); }
.tier-card:nth-child(4) .tier-banner { background: linear-gradient(to bottom right, #065f46, #111827); }

.tier-rank {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    color: #fff;
    padding: 0.25rem 0.5rem;
    border-radius: 0.25rem;
    width: max-content;
    margin-bottom: 0.5rem;
}
.tier-card:nth-child(1) .tier-rank { background-color: rgba(59, 130, 246, 0.2); color: #93c5fd; }
.tier-card:nth-child(2) .tier-rank { background-color: rgba(168, 85, 247, 0.2); color: #d8b4fe; }
.tier-card:nth-child(3) .tier-rank { background-color: rgba(99, 102, 241, 0.2); color: #a5b4fc; }
.tier-card:nth-child(4) .tier-rank { background-color: rgba(16, 185, 129, 0.2); color: #6ee7b7; }

.tier-name {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-white);
}

.tier-body {
    padding: 1.5rem;
}
.tier-subtitle {
    font-weight: 500;
    color: var(--text-white);
    margin-bottom: 0.5rem;
}
.tier-desc {
    font-size: 0.875rem;
    color: var(--muted);
    line-height: 1.5;
}

/* Footer */
footer {
    border-top: 1px solid var(--border);
    padding: 2rem 0;
    text-align: center;
    color: var(--muted);
    font-size: 0.875rem;
}