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

:root {
    --color-bg: #fafafa;
    --color-text: #333;
    --color-text-muted: #666;
    --color-border: #e0e0e0;
    --color-card-bg: #fff;
    --color-primary: #0066ff;
    --color-success: #00c853;
    --font-main: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --sidebar-width: 200px;
    --slideout-width: 220px;
}

body {
    font-family: var(--font-main);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* Header */
.header {
    background: var(--color-card-bg);
    border-bottom: 1px solid var(--color-text);
    padding: 0 2rem;
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}

.site-title {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--color-text);
    letter-spacing: 0.05em;
    text-transform: uppercase;
    font-family: monospace;
}

.gateway-tabs {
    display: flex;
    gap: 0;
}

.tab-button {
    background: none;
    border: 1px solid var(--color-text);
    border-right: none;
    padding: 0.5rem 1.25rem;
    font-size: 0.875rem;
    color: var(--color-text);
    cursor: pointer;
    transition: all 0.15s;
    font-weight: 500;
    font-family: monospace;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.tab-button:first-child {
    border-top-left-radius: 0;
    border-bottom-left-radius: 0;
}

.tab-button:last-child {
    border-right: 1px solid var(--color-text);
    border-top-right-radius: 0;
    border-bottom-right-radius: 0;
}

.tab-button:hover {
    background: var(--color-text);
    color: var(--color-card-bg);
}

.tab-button.active {
    background: var(--color-text);
    color: var(--color-card-bg);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.card-toggle {
    background: var(--color-card-bg);
    border: 1px solid var(--color-text);
    padding: 0.5rem 0.875rem;
    cursor: pointer;
    font-size: 0.875rem;
    color: var(--color-text);
    transition: all 0.15s;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
    font-family: monospace;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.menu-button {
    background: none;
    border: none;
    padding: 0.5rem 0.875rem;
    cursor: pointer;
    font-size: 0.875rem;
    color: var(--color-text);
    transition: all 0.15s;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.card-toggle:hover {
    background: var(--color-text);
    color: var(--color-card-bg);
}

.menu-button:hover {
    opacity: 0.7;
}

.card-toggle:active,
.menu-button:active {
    opacity: 0.8;
}

.card-toggle svg,
.menu-button svg {
    width: 16px;
    height: 16px;
}

/* Dropdown Menu */
.dropdown {
    position: relative;
}

.dropdown-content {
    position: absolute;
    top: calc(100% + 0.5rem);
    right: 0;
    background: var(--color-card-bg);
    border: 1px solid var(--color-text);
    min-width: 180px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all 0.2s;
    z-index: 200;
}

.dropdown-content.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-link {
    display: block;
    padding: 0.75rem 1rem;
    color: var(--color-text);
    text-decoration: none;
    font-size: 0.875rem;
    transition: background 0.15s;
    border-bottom: 1px solid var(--color-text);
    font-family: monospace;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.dropdown-link:last-child {
    border-bottom: none;
}

.dropdown-link:hover {
    background: var(--color-text);
    color: var(--color-card-bg);
}

/* Main Layout */
.main-container {
    display: flex;
    max-width: 1400px;
    margin: 0 auto;
    min-height: calc(100vh - 60px);
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: var(--color-card-bg);
    border-right: 1px solid var(--color-text);
    padding: 1.5rem 1rem;
    overflow-y: overlay;
    position: fixed;
    top: 60px;
    bottom: 0;
    left: 0;
    z-index: 60;
}

.sidebar::-webkit-scrollbar {
    width: 8px;
}

.sidebar::-webkit-scrollbar-track {
    background: transparent;
}

.sidebar::-webkit-scrollbar-thumb {
    background: var(--color-border);
}

.sidebar::-webkit-scrollbar-thumb:hover {
    background: var(--color-text-muted);
}

.sidebar-section {
    margin-bottom: 2rem;
}

.sidebar-divider {
    height: 1px;
    background: var(--color-text);
    margin: 2rem -1rem;
}

.sidebar-label {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text);
    margin-bottom: 0.75rem;
    font-weight: 700;
    font-family: monospace;
}

.option-button {
    display: block;
    width: 100%;
    background: var(--color-card-bg);
    border: 1px solid var(--color-text);
    padding: 0.6rem 0.75rem;
    margin-bottom: 0.4rem;
    text-align: left;
    cursor: pointer;
    font-size: 0.85rem;
    color: var(--color-text);
    transition: all 0.15s;
    font-weight: 500;
}

.option-button:hover {
    background: var(--color-bg);
}

.option-button:active {
    opacity: 0.8;
}

.option-button.active {
    background: var(--color-text);
    color: var(--color-card-bg);
    border-color: var(--color-text);
}

.see-all-button {
    display: block;
    width: 100%;
    background: none;
    border: none;
    padding: 0.5rem 0.75rem;
    text-align: center;
    cursor: pointer;
    font-size: 0.8rem;
    color: var(--color-text);
    transition: all 0.15s;
    font-weight: 500;
    font-family: monospace;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.see-all-button:hover {
    opacity: 0.7;
}

/* Accordion for Disclaimer */
.disclaimer-accordion {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--color-text);
    margin-left: -1rem;
    margin-right: -1rem;
    padding-left: 1rem;
    padding-right: 1rem;
}

.accordion-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    padding: 0.5rem 0;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    font-weight: 700;
    font-family: monospace;
    color: var(--color-text);
}

.accordion-icon {
    transition: transform 0.2s;
    font-size: 0.8rem;
}

.accordion-icon.open {
    transform: rotate(180deg);
}

.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.accordion-content.open {
    max-height: 500px;
    padding-top: 0.75rem;
}

.disclaimer-text {
    font-size: 0.7rem;
    color: var(--color-text-muted);
    line-height: 1.5;
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .sidebar {
        position: static;
        width: 100%;
        border-right: none;
        border-bottom: 1px solid var(--color-text);
        padding: 1rem;
    }
    
    .sidebar-section {
        margin-bottom: 1rem;
    }
    
    .sidebar-divider {
        margin: 1rem -1rem;
    }
    
    /* Hide button list, show dropdown instead */
    .option-button {
        display: none;
    }
    
    .see-all-button {
        display: none;
    }
    
    /* Mobile dropdowns */
    .mobile-dropdown {
        width: 100%;
        padding: 0.6rem 0.75rem;
        border: 1px solid var(--color-text);
        background: var(--color-card-bg);
        font-size: 0.85rem;
        font-weight: 500;
        cursor: pointer;
        font-family: inherit;
    }
    
    .mobile-dropdown:focus {
        outline: 2px solid var(--color-text);
        outline-offset: 2px;
    }
    
    .content {
        position: static;
        left: 0;
        padding: 2rem 1rem;
    }
    
    .slideout-panel {
        display: none;
    }
    
    .disclaimer-accordion {
        margin-top: 1rem;
        padding-top: 1rem;
    }
    
    .header-content {
        flex-wrap: wrap;
        gap: 1rem;
    }
    
    .gateway-tabs {
        order: 3;
        width: 100%;
        justify-content: space-between;
    }
    
    .tab-button {
        flex: 1;
        padding: 0.5rem 0.5rem;
        font-size: 0.75rem;
    }
}

/* Slide-out Panel */
.slideout-panel {
    width: var(--slideout-width);
    background: var(--color-card-bg);
    border-right: 1px solid var(--color-border);
    padding: 1.5rem 1rem;
    overflow-y: auto;
    position: fixed;
    top: 60px;
    bottom: 0;
    left: 0;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    z-index: 50;
    box-shadow: 2px 0 8px rgba(0,0,0,0.05);
}

.slideout-panel.open {
    transform: translateX(var(--sidebar-width));
}

.slideout-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.slideout-title {
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--color-text);
    font-family: monospace;
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.close-slideout {
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.25rem;
    color: var(--color-text-muted);
    transition: color 0.2s;
}

.close-slideout:hover {
    color: var(--color-text);
}

.close-slideout svg {
    width: 20px;
    height: 20px;
}

/* Content Area */
.content {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 3rem;
    position: fixed;
    top: 60px;
    right: 0;
    bottom: 0;
    left: var(--sidebar-width);
    overflow: hidden;
    transition: left 0.3s ease;
    background: #2a2a2a;
}

.content.with-slideout {
    left: calc(var(--sidebar-width) + var(--slideout-width));
}

.card-container {
    text-align: center;
    max-width: 700px;
    width: 100%;
}

/* Credit Card */
.credit-card {
    width: 100%;
    max-width: 550px;
    aspect-ratio: 1.586;
    margin: 0 auto 2rem;
    border-radius: 20px;
    padding: 2.5rem;
    position: relative;
    cursor: pointer;
    transition: transform 0.3s, box-shadow 0.3s;
    box-shadow: 0 10px 30px rgba(0,0,0,0.12);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    color: white;
    background-size: cover;
    background-position: center;
}

.credit-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 32px rgba(0,0,0,0.15);
}

.credit-card.copied {
    animation: cardPulse 0.4s ease-out;
}

@keyframes cardPulse {
    0%, 100% { transform: scale(1) translateY(0); }
    50% { transform: scale(1.02) translateY(-2px); }
}

.card-chip {
    width: 50px;
    height: 40px;
    background: linear-gradient(135deg, #f0c27b 0%, #4b1248 100%);
    border-radius: 6px;
    margin-bottom: 2rem;
}

.card-number {
    font-size: 2rem;
    letter-spacing: 0.15em;
    font-weight: 700;
    margin-bottom: 2.5rem;
    font-family: 'Courier New', monospace;
    text-shadow: 0 2px 4px rgba(0,0,0,0.2);
    text-align: center;
}

.card-details {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    width: 100%;
}

.card-detail-item {
    text-align: left;
}

.card-detail-label {
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    opacity: 0.8;
    margin-bottom: 0.25rem;
}

.card-detail-value {
    font-size: 0.95rem;
    font-weight: 500;
}

/* Scenario Label */
.scenario-label {
    font-size: 1.1rem;
    color: #ffffff;
    margin-bottom: 1rem;
    font-family: monospace;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.copy-hint {
    font-size: 0.9rem;
    color: #ffffff;
    margin-top: 1rem;
    cursor: pointer;
    transition: opacity 0.2s;
}

.copy-hint:hover {
    opacity: 0.7;
}

.artist-info {
    font-size: 0.85rem;
    color: #999;
    margin-top: 1.5rem;
}

.artist-name {
    color: #999;
    font-weight: 500;
}

.artist-link {
    color: #999;
    text-decoration: none;
    transition: opacity 0.2s;
}

.artist-link:hover {
    opacity: 0.7;
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    transform: translateX(200px);
    background: var(--color-card-bg);
    color: var(--color-text);
    padding: 1rem 1.5rem;
    border: 2px solid var(--color-text);
    opacity: 0;
    transition: all 0.3s;
    z-index: 1000;
    font-family: monospace;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    font-size: 0.875rem;
    font-weight: 700;
}

.toast.show {
    transform: translateX(0);
    opacity: 1;
}

/* Responsive */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        height: auto;
        padding: 1rem 0;
        gap: 1rem;
    }

    .main-container {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        border-right: none;
        border-bottom: 1px solid var(--color-border);
        padding: 1.25rem;
        position: static;
        max-height: 40vh;
        overflow-y: auto;
    }

    .slideout-panel {
        width: 100%;
        left: 0;
        top: auto;
        bottom: 0;
        transform: translateY(100%);
        max-height: 60vh;
    }

    .slideout-panel.open {
        transform: translateY(0);
    }

    .sidebar-section {
        margin-bottom: 1.5rem;
    }

    .content {
        position: static;
        padding: 2rem 1.5rem;
        left: 0;
    }

    .content.with-slideout {
        left: 0;
    }

    .credit-card {
        max-width: 100%;
        padding: 1.5rem;
    }

    .card-number {
        font-size: 1.4rem;
    }

    .gateway-tabs {
        width: 100%;
        justify-content: center;
    }

    .tab-button {
        flex: 1;
        padding: 0.6rem 0.5rem;
        font-size: 0.8rem;
    }
}

/* Card Background Gradients */
.card-gradient-1 {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}
.card-gradient-2 {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}
.card-gradient-3 {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}
.card-gradient-4 {
    background: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
}
.card-gradient-5 {
    background: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
}
.card-gradient-6 {
    background: linear-gradient(135deg, #30cfd0 0%, #330867 100%);
}
.card-gradient-7 {
    background: linear-gradient(135deg, #a8edea 0%, #fed6e3 100%);
}
.card-gradient-8 {
    background: linear-gradient(135deg, #ff9a9e 0%, #fecfef 100%);
}