:root {
    --amex-blue: #006FCF;
    --amex-dark-blue: #002663;
    --amex-light-blue: #E6F0FA;
    --white: #FFFFFF;
    --gray-50: #F8FAFC;
    --gray-100: #F1F5F9;
    --gray-200: #E2E8F0;
    --gray-600: #475569;
    --gray-800: #1E293B;
    --gray-900: #0F172A;
    --accent-gold: #D4AF37;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--gray-800);
    background-color: var(--gray-50);
}

/* Sidebar Navigation */
.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    width: 260px;
    height: 100vh;
    background: linear-gradient(180deg, var(--amex-dark-blue) 0%, var(--amex-blue) 100%);
    padding: 2rem 0;
    overflow-y: auto;
    z-index: 1000;
    box-shadow: 4px 0 15px rgba(0,0,0,0.1);
}

.sidebar-brand {
    text-align: center;
    padding: 0 1.5rem 2rem;
    border-bottom: 1px solid rgba(255,255,255,0.2);
}

.sidebar-brand h2 {
    color: var(--white);
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: 0.5px;
}

.sidebar-brand span {
    color: var(--accent-gold);
    font-size: 0.85rem;
    display: block;
    margin-top: 0.25rem;
}

.nav-menu {
    list-style: none;
    padding: 1.5rem 0;
}

.nav-menu li {
    margin: 0.25rem 0;
}

.nav-menu a {
    display: flex;
    align-items: center;
    padding: 0.875rem 1.5rem;
    color: rgba(255,255,255,0.9);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    border-left: 3px solid transparent;
}

.nav-menu a:hover, .nav-menu a.active {
    background: rgba(255,255,255,0.1);
    color: var(--white);
    border-left-color: var(--accent-gold);
}

.nav-menu i {
    width: 24px;
    margin-right: 12px;
    font-style: normal;
}

.social-links {
    padding: 1.5rem;
    border-top: 1px solid rgba(255,255,255,0.2);
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.social-links a {
    width: 40px;
    height: 40px;
    background: rgba(255,255,255,0.15);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    text-decoration: none;
    transition: all 0.3s ease;
}

.social-links a:hover {
    background: var(--white);
    color: var(--amex-blue);
    transform: translateY(-2px);
}

/* Main Content */
.main-content {
    margin-left: 260px;
    min-height: 100vh;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--amex-dark-blue) 0%, var(--amex-blue) 100%);
    color: var(--white);
    padding: 4rem 3rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -10%;
    width: 500px;
    height: 500px;
    background: rgba(255,255,255,0.03);
    border-radius: 50%;
}

.hero h1 {
    font-size: 2.75rem;
    font-weight: 800;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero .lead {
    font-size: 1.25rem;
    opacity: 0.95;
    max-width: 700px;
    margin: 0 auto 2rem;
}

.ai-summary {
    background: rgba(255,255,255,0.15);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: 12px;
    padding: 1.25rem 2rem;
    max-width: 800px;
    margin: 0 auto 2rem;
    font-size: 1.05rem;
    line-height: 1.5;
}

.cta-button {
    display: inline-block;
    background: var(--white);
    color: var(--amex-blue);
    padding: 1rem 2.5rem;
    border-radius: 50px;
    font-weight: 700;
    font-size: 1.1rem;
    text-decoration: none;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    transition: all 0.3s ease;
    margin-top: 1rem;
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0,0,0,0.3);
}

/* Content Container */
.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 3rem 2rem;
}

.content-section {
    background: var(--white);
    border-radius: 16px;
    padding: 2.5rem;
    margin-bottom: 2rem;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    border: 1px solid var(--gray-200);
}

h2 {
    color: var(--amex-dark-blue);
    font-size: 1.875rem;
    font-weight: 700;
    margin-bottom: 1.25rem;
    padding-bottom: 0.75rem;
    border-bottom: 3px solid var(--amex-blue);
    display: inline-block;
}

h3 {
    color: var(--amex-blue);
    font-size: 1.4rem;
    font-weight: 600;
    margin: 2rem 0 1rem;
}

h4 {
    color: var(--gray-800);
    font-size: 1.15rem;
    font-weight: 600;
    margin: 1.5rem 0 0.75rem;
}

p {
    margin-bottom: 1.25rem;
    color: var(--gray-600);
    font-size: 1.05rem;
    line-height: 1.7;
}

.highlight-box {
    background: var(--amex-light-blue);
    border-left: 4px solid var(--amex-blue);
    padding: 1.25rem 1.5rem;
    border-radius: 0 8px 8px 0;
    margin: 1.5rem 0;
}

.warning-box {
    background: #FEF3C7;
    border-left: 4px solid #F59E0B;
    padding: 1.25rem 1.5rem;
    border-radius: 0 8px 8px 0;
    margin: 1.5rem 0;
}

.success-box {
    background: #D1FAE5;
    border-left: 4px solid #10B981;
    padding: 1.25rem 1.5rem;
    border-radius: 0 8px 8px 0;
    margin: 1.5rem 0;
}

ol, ul {
    margin: 1rem 0 1.5rem 1.5rem;
    color: var(--gray-600);
}

li {
    margin-bottom: 0.75rem;
    line-height: 1.6;
}

.step-list {
    list-style: none;
    margin-left: 0;
    counter-reset: step;
}

.step-list li {
    position: relative;
    padding-left: 3rem;
    margin-bottom: 1.5rem;
}

.step-list li::before {
    counter-increment: step;
    content: counter(step);
    position: absolute;
    left: 0;
    top: 0;
    width: 2rem;
    height: 2rem;
    background: var(--amex-blue);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.875rem;
}

.phone-number {
    display: inline-block;
    background: var(--amex-dark-blue);
    color: var(--white);
    padding: 0.5rem 1rem;
    border-radius: 6px;
    font-weight: 700;
    font-family: monospace;
    font-size: 1.1rem;
    letter-spacing: 0.5px;
}

.faq-item {
    border-bottom: 1px solid var(--gray-200);
    padding: 1.5rem 0;
}

.faq-item:last-child {
    border-bottom: none;
}

.faq-question {
    font-weight: 700;
    color: var(--amex-dark-blue);
    font-size: 1.15rem;
    margin-bottom: 0.75rem;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.faq-answer {
    color: var(--gray-600);
    line-height: 1.7;
    padding-left: 0.5rem;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 1.5rem 0;
    font-size: 0.95rem;
}

th {
    background: var(--amex-blue);
    color: var(--white);
    padding: 1rem;
    text-align: left;
    font-weight: 600;
}

td {
    padding: 1rem;
    border-bottom: 1px solid var(--gray-200);
    color: var(--gray-600);
}

tr:nth-child(even) {
    background: var(--gray-50);
}

.citation {
    color: var(--amex-blue);
    font-size: 0.85rem;
    text-decoration: none;
    font-weight: 500;
}

.citation:hover {
    text-decoration: underline;
}

/* Footer */
.footer {
    background: var(--gray-900);
    color: var(--gray-200);
    padding: 3rem 2rem;
    margin-left: 260px;
    text-align: center;
}

.app-downloads {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.store-badge {
    width: 200px;
    height: 60px;
    background: var(--gray-800);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    text-decoration: none;
    font-weight: 600;
    border: 1px solid var(--gray-600);
    transition: all 0.3s ease;
    cursor: pointer;
}

.store-badge:hover {
    background: var(--gray-700);
    transform: translateY(-2px);
}

.store-badge.playstore::before {
    content: "▶ ";
    color: #34A853;
    font-size: 1.5rem;
}

.store-badge.appstore::before {
    content: "⌘ ";
    color: var(--white);
    font-size: 1.5rem;
}

.url-placeholder {
    background: var(--gray-800);
    border: 2px dashed var(--gray-600);
    border-radius: 8px;
    padding: 1rem;
    margin: 1rem 0;
    font-family: monospace;
    color: var(--gray-400);
    font-size: 0.9rem;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--gray-400);
    text-decoration: none;
    transition: color 0.3s;
}

.footer-links a:hover {
    color: var(--white);
}

.copyright {
    color: var(--gray-600);
    font-size: 0.875rem;
}

/* Mobile Toggle */
.mobile-toggle {
    display: none;
    position: fixed;
    top: 1rem;
    left: 1rem;
    z-index: 1001;
    background: var(--amex-blue);
    color: var(--white);
    border: none;
    padding: 0.75rem;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1.25rem;
}

/* Responsive */
@media (max-width: 1024px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform 0.3s ease;
    }
    
    .sidebar.active {
        transform: translateX(0);
    }
    
    .main-content, .footer {
        margin-left: 0;
    }
    
    .mobile-toggle {
        display: block;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
}

@media (max-width: 640px) {
    .container {
        padding: 1.5rem 1rem;
    }
    
    .content-section {
        padding: 1.5rem;
    }
    
    .hero {
        padding: 3rem 1.5rem;
    }
}

/* Smooth Scroll */
html {
    scroll-behavior: smooth;
    scroll-padding-top: 2rem;
}

/* Anchor targets */
[id] {
    scroll-margin-top: 2rem;
}