:root {
    --background: 0 0% 100%;
    --foreground: 222.2 84% 4.9%;
    --card: 0 0% 100%;
    --card-foreground: 222.2 84% 4.9%;
    --popover: 0 0% 100%;
    --popover-foreground: 222.2 84% 4.9%;
    --primary: 222.2 47.4% 11.2%;
    --primary-foreground: 210 40% 98%;
    --secondary: 210 40% 96.1%;
    --secondary-foreground: 222.2 47.4% 11.2%;
    --muted: 210 40% 96.1%;
    --muted-foreground: 215.4 16.3% 46.9%;
    --accent: 210 40% 96.1%;
    --accent-foreground: 222.2 47.4% 11.2%;
    --destructive: 0 84.2% 60.2%;
    --destructive-foreground: 210 40% 98%;
    --border: 214.3 32.1% 91.4%;
    --input: 214.3 32.1% 91.4%;
    --ring: 222.2 84% 4.9%;
    --radius: 0.5rem;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    background-color: hsl(var(--background));
    color: hsl(var(--foreground));
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

header {
    height: 64px;
    border-bottom: 1px solid hsl(var(--border));
    display: flex;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 50;
    background-color: hsla(var(--background) / 0.8);
    backdrop-filter: blur(8px);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    font-size: 1.1rem;
    text-decoration: none;
    color: hsl(var(--foreground));
}

.logo img {
    height: 24px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    height: 40px;
    padding: 0 1rem;
    transition: background-color 0.2s, opacity 0.2s;
    cursor: pointer;
    border: none;
    text-decoration: none;
}

.btn-primary {
    background-color: hsl(var(--primary));
    color: hsl(var(--primary-foreground));
}

.btn-primary:hover {
    opacity: 0.9;
}

.btn-secondary {
    background-color: hsl(var(--secondary));
    color: hsl(var(--secondary-foreground));
    border: 1px solid hsl(var(--border));
}

.btn-secondary:hover {
    background-color: hsl(var(--accent));
}

.hero {
    padding: 6rem 0;
    text-align: center;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    letter-spacing: -0.05rem;
    margin-bottom: 1.5rem;
    line-height: 1.1;
}

.hero p {
    font-size: 1.25rem;
    color: hsl(var(--muted-foreground));
    max-width: 700px;
    margin: 0 auto 2.5rem;
}

.hero-image {
    width: 100%;
    max-width: 800px;
    border-radius: var(--radius);
    border: 1px solid hsl(var(--border));
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    margin-bottom: 3rem;
}

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

input[type="text"],
input[type="email"] {
    width: 100%;
    height: 40px;
    padding: 0 0.75rem;
    border-radius: var(--radius);
    border: 1px solid hsl(var(--border));
    background-color: hsl(var(--background));
    font-size: 0.875rem;
    transition: border-color 0.2s;
}

input:focus {
    outline: none;
    border-color: hsl(var(--ring));
}

.checkbox-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.checkbox-group input {
    width: 16px;
    height: 16px;
    accent-color: hsl(var(--primary));
}

/* Grid Layout for Download Page */
.page-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    padding: 4rem 0;
}

@media (max-width: 768px) {
    .page-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

/* Popup */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 100;
}

.modal-content {
    background-color: hsl(var(--background));
    padding: 2rem;
    border-radius: var(--radius);
    max-width: 400px;
    width: 90%;
    text-align: center;
    border: 1px solid hsl(var(--border));
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

.modal-content h3 {
    margin-bottom: 1rem;
}

.modal-content p {
    color: hsl(var(--muted-foreground));
    margin-bottom: 1.5rem;
}

/* Donation Page */
.donation-card {
    max-width: 600px;
    margin: 4rem auto;
    padding: 2.5rem;
    border: 1px solid hsl(var(--border));
    border-radius: var(--radius);
    background-color: hsl(var(--card));
}

.btc-address {
    background-color: hsl(var(--muted));
    padding: 1rem;
    border-radius: var(--radius);
    font-family: monospace;
    font-size: 1rem;
    word-break: break-all;
    margin: 1.5rem 0;
    text-align: center;
    border: 1px dashed hsl(var(--border));
}

.badge {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
    background-color: hsl(var(--secondary));
    color: hsl(var(--secondary-foreground));
    margin-bottom: 1rem;
}