/* ============================================
   U.S. ELITE INVESTMENT CLUB - DESIGN SYSTEM
   精英投资俱乐部 - 设计系统
   ============================================ */

/* ===== COLOR PALETTE ===== */
:root {
    /* Primary Colors - Muted Bronze & Deep Slate */
    --bronze-50: #f5f1ea;
    --bronze-100: #e8dfc9;
    --bronze-200: #d4c19a;
    --bronze-300: #c9b37e;  /* Main Bronze */
    --bronze-400: #b39d6a;
    --bronze-500: #9d8757;
    --bronze-600: #7d6b45;
    
    --slate-900: #0f172a;
    --slate-800: #1e293b;
    --slate-700: #334155;
    --slate-600: #475569;
    
    /* Opacity Levels */
    --overlay-light: rgba(201, 179, 126, 0.08);
    --overlay-medium: rgba(201, 179, 126, 0.15);
    --overlay-heavy: rgba(201, 179, 126, 0.25);
    
    /* Background Layers */
    --bg-primary: #0a0f1a;
    --bg-card: rgba(30, 41, 59, 0.25);
    --bg-card-hover: rgba(30, 41, 59, 0.4);
    
    /* Spacing Scale - Increased for "Breathing Room" */
    --space-xs: 0.75rem;    /* 12px */
    --space-sm: 1rem;        /* 16px */
    --space-md: 1.5rem;      /* 24px */
    --space-lg: 2.5rem;      /* 40px */
    --space-xl: 4rem;        /* 64px */
    --space-2xl: 6rem;       /* 96px */
    --space-3xl: 8rem;       /* 128px */
}

/* ===== TYPOGRAPHY SYSTEM ===== */

/* Primary Font Stack */
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 16px;
    line-height: 1.7;
    color: #e2e8f0;
    background: var(--bg-primary);
    letter-spacing: 0.01em;
}

/* Elegant Serif for Important Headings */
.heading-serif {
    font-family: 'Playfair Display', 'Georgia', serif;
    font-weight: 500;
    letter-spacing: -0.02em;
}

/* Modern Sans for Body & UI */
.text-sans {
    font-family: 'Inter', sans-serif;
    letter-spacing: 0.01em;
}

/* Monospace for Numbers & Data */
.text-mono {
    font-family: 'Roboto Mono', 'Courier New', monospace;
    letter-spacing: -0.01em;
}

/* Heading Hierarchy - Refined Sizes */
h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 500;
    line-height: 1.15;
    letter-spacing: -0.03em;
    margin-bottom: var(--space-lg);
}

h2 {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 500;
    line-height: 1.25;
    letter-spacing: -0.02em;
    margin-bottom: var(--space-md);
}

h3 {
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 500;
    line-height: 1.35;
    letter-spacing: -0.01em;
    margin-bottom: var(--space-sm);
}

p {
    line-height: 1.8;
    margin-bottom: var(--space-md);
}

/* ===== CARD SYSTEM ===== */

/* Base Card - Minimal & Elegant */
.elite-card {
    background: var(--bg-card);
    border: 1px solid var(--overlay-medium);
    border-radius: 16px;
    padding: var(--space-xl);
    transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

.elite-card:hover {
    transform: translateY(-4px);
    border-color: var(--bronze-300);
    box-shadow: 0 12px 40px rgba(201, 179, 126, 0.12);
    background: var(--bg-card-hover);
}

/* Feature Card - More Spacing */
.feature-card {
    background: rgba(30, 41, 59, 0.2);
    border: 1px solid var(--overlay-light);
    border-radius: 20px;
    padding: var(--space-2xl) var(--space-xl);
    transition: all 0.4s ease;
}

.feature-card:hover {
    border-color: var(--bronze-300);
    transform: translateY(-6px);
    box-shadow: 0 16px 50px rgba(201, 179, 126, 0.15);
}

/* ===== BUTTON SYSTEM ===== */

/* Ghost Button - Primary CTA Style (Refined) */
.btn-ghost {
    display: inline-block;
    padding: 1rem 2.5rem;
    background: transparent;
    border: 2px solid var(--bronze-300);
    color: var(--bronze-300);
    font-size: 1rem;
    font-weight: 500;
    border-radius: 10px;
    text-decoration: none;
    transition: all 0.35s ease;
    cursor: pointer;
    letter-spacing: 0.02em;
}

.btn-ghost:hover {
    background: var(--overlay-light);
    border-color: var(--bronze-200);
    color: var(--bronze-200);
    box-shadow: 0 8px 24px rgba(201, 179, 126, 0.2);
    transform: translateY(-2px);
}

/* Subtle Text Link with Arrow */
.link-arrow {
    display: inline-flex;
    align-items: center;
    color: var(--bronze-300);
    font-weight: 500;
    text-decoration: none;
    transition: all 0.3s ease;
    gap: 0.5rem;
}

.link-arrow:hover {
    color: var(--bronze-200);
    transform: translateX(4px);
}

.link-arrow::after {
    content: '→';
    font-size: 1.2em;
    transition: transform 0.3s ease;
}

.link-arrow:hover::after {
    transform: translateX(4px);
}

/* Secondary Button - Understated */
.btn-secondary {
    display: inline-block;
    padding: 0.875rem 2rem;
    background: rgba(30, 41, 59, 0.5);
    border: 1px solid var(--overlay-medium);
    color: #e2e8f0;
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: 8px;
    text-decoration: none;
    transition: all 0.3s ease;
}

.btn-secondary:hover {
    background: rgba(30, 41, 59, 0.7);
    border-color: var(--bronze-300);
    color: var(--bronze-200);
}

/* ===== LAYOUT UTILITIES ===== */

/* Breathing Space Between Sections */
.section-spacer {
    padding: var(--space-3xl) 0;
}

.section-spacer-sm {
    padding: var(--space-2xl) 0;
}

/* Content Container with Max Width */
.content-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

/* Narrow Content for Reading */
.content-narrow {
    max-width: 800px;
    margin: 0 auto;
}

/* ===== ACCENTS & DECORATIONS ===== */

/* Subtle Underline Accent */
.accent-underline {
    position: relative;
    display: inline-block;
}

.accent-underline::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 60px;
    height: 2px;
    background: linear-gradient(90deg, var(--bronze-300), transparent);
}

/* Gold Dot Separator */
.dot-separator {
    display: inline-block;
    width: 4px;
    height: 4px;
    background: var(--bronze-300);
    border-radius: 50%;
    margin: 0 1rem;
    vertical-align: middle;
}

/* Section Divider - Elegant */
.section-divider {
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--overlay-medium), transparent);
    margin: var(--space-2xl) 0;
}

/* ===== BRONZE ACCENT UTILITIES ===== */

.text-bronze {
    color: var(--bronze-300);
}

.text-bronze-light {
    color: var(--bronze-200);
}

.border-bronze {
    border-color: var(--bronze-300);
}

.bg-bronze-subtle {
    background: var(--overlay-light);
}

/* ===== HOVER STATES ===== */

.hover-lift {
    transition: transform 0.3s ease;
}

.hover-lift:hover {
    transform: translateY(-4px);
}

/* ===== ANIMATIONS ===== */

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-fade-in-up {
    animation: fadeInUp 0.8s ease-out forwards;
}

/* ===== RESPONSIVE BREAKPOINTS ===== */

@media (max-width: 768px) {
    :root {
        --space-xl: 2.5rem;
        --space-2xl: 4rem;
        --space-3xl: 5rem;
    }
    
    .elite-card {
        padding: var(--space-lg);
    }
    
    .feature-card {
        padding: var(--space-xl) var(--space-lg);
    }
}

/* ===== PROFESSIONAL IMAGERY ===== */

.elite-image {
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
}

.elite-avatar {
    border-radius: 50%;
    border: 3px solid var(--overlay-medium);
    transition: border-color 0.3s ease;
}

.elite-avatar:hover {
    border-color: var(--bronze-300);
}