:root {
    /* Color Palette - Elegant Dark Mode with Soft Gradients */
    --bg-color-1: #1a1a2e;
    --bg-color-2: #16213e;
    --bg-color-3: #0f3460;
    --text-primary: #f8f9fa;
    --text-secondary: #ced4da;
    --accent-color: #e94560;
    
    /* Glassmorphism */
    --glass-bg: rgba(255, 255, 255, 0.95);
    --glass-border: rgba(255, 255, 255, 1);
    --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.15);
    
    /* Inverted Text Colors for Card */
    --card-text-primary: #1a1a2e;
    --card-text-secondary: #495057;
}

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

body {
    font-family: 'Inter', sans-serif;
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow-x: hidden;
    position: relative;
    background-color: var(--bg-color-1);
    line-height: 1.6;
}

/* Dynamic Animated Background */
.background-animation {
    position: absolute;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: linear-gradient(45deg, var(--bg-color-1), var(--bg-color-2), var(--bg-color-3));
    background-size: 400% 400%;
    animation: gradientBG 15s ease infinite;
    z-index: -1;
}

@keyframes gradientBG {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.container {
    padding: 2rem;
    width: 100%;
    max-width: 800px;
    z-index: 1;
}

/* Glassmorphism Card */
.glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: 3rem 4rem;
    box-shadow: var(--glass-shadow);
    transform: translateY(20px);
    opacity: 0;
    animation: fadeUp 1s ease-out forwards;
    color: var(--card-text-primary);
}

@keyframes fadeUp {
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

/* Logo Area */
.logo-placeholder {
    text-align: center;
    margin-bottom: 3rem;
}

.logo-img {
    max-width: 250px;
    height: auto;
    transition: transform 0.3s ease;
    filter: drop-shadow(0 4px 10px rgba(0, 0, 0, 0.3));
}

.logo-img:hover {
    transform: scale(1.05);
}

/* Content Typography */
.message-content p {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
    color: var(--card-text-secondary);
    transition: color 0.3s ease;
}

.message-content p:hover {
    color: var(--card-text-primary);
}

.message-content strong {
    color: var(--card-text-primary);
    font-weight: 600;
}

.greeting {
    font-size: 1.3rem !important;
    font-weight: 600;
    color: var(--card-text-primary) !important;
}

.gratitude {
    margin-top: 2.5rem;
    font-style: italic;
    color: var(--card-text-primary) !important;
}

/* Signature */
.signature-wrapper {
    margin-top: 3rem;
    text-align: right;
    animation: fadeIn 2s ease-in forwards;
    animation-delay: 1s;
    opacity: 0;
}

.signature {
    font-family: 'Playfair Display', serif;
    font-style: italic;
    font-size: 3rem;
    color: var(--card-text-primary);
    display: block;
    line-height: 1;
}

.hearts {
    font-size: 1.5rem;
    display: inline-block;
    margin-top: 0.5rem;
    animation: heartbeat 2s infinite;
}

@keyframes heartbeat {
    0% { transform: scale(1); }
    10% { transform: scale(1.2); }
    20% { transform: scale(1); }
    30% { transform: scale(1.2); }
    40% { transform: scale(1); }
    100% { transform: scale(1); }
}

@keyframes fadeIn {
    to { opacity: 1; }
}

/* Responsive */
@media (max-width: 768px) {
    .glass-card {
        padding: 2rem;
    }
    
    .message-content p {
        font-size: 1rem;
    }
    
    .signature {
        font-size: 2.5rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 1rem;
    }
    
    .glass-card {
        padding: 1.5rem;
        border-radius: 16px;
    }
}