:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #dbeafe;
    --secondary: #64748b;
    --accent: #f59e0b;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --info: #3b82f6;

    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --gray-900: #0f172a;

    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #64748b;
    --muted: #94a3b8;
    --light: #f8fafc;

    --border-light: #e2e8f0;
    --border-medium: #cbd5e1;

    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
}

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

html {
    font-size: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
    background: var(--gray-50);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

a {
    color: inherit;
}

a:hover {
    color: inherit;
}

.header {
    background: rgba(255, 255, 255, 0.96);
    border-bottom: 1px solid var(--border-light);
    box-shadow: var(--shadow-sm);
    position: relative;
    z-index: 100;
}

.header--frosted {
    backdrop-filter: blur(8px);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    gap: 1rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-links {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 0.5rem;
    transition: all 0.2s ease;
}

.nav-links a:hover,
.nav-links a:focus-visible {
    color: var(--primary);
    background: var(--gray-100);
}

.main-container,
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 6rem 2rem 4rem;
}

.btn {
    display: inline-flex;
    justify-content: center;
    align-items: center;
    gap: 0.5rem;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: 0.75rem;
    padding: 0.75rem 1.75rem;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.2s ease;
}

.btn:hover,
.btn:focus-visible {
    background: var(--primary-dark);
}

.btn-secondary {
    background: var(--secondary);
}

.btn-success {
    background: var(--success);
}

.btn-danger {
    background: var(--danger);
}

.btn-secondary:hover,
.btn-secondary:focus-visible {
    background: var(--gray-600);
}

.btn-success:hover,
.btn-success:focus-visible {
    background: #0f9f62;
}

.btn-danger:hover,
.btn-danger:focus-visible {
    background: #d03434;
}

.btn-ghost {
    background: transparent;
    color: var(--primary);
    border: 1px solid var(--primary);
}

.btn-ghost:hover,
.btn-ghost:focus-visible {
    background: var(--primary);
    color: #fff;
}

.card {
    background: #fff;
    border: 1px solid var(--border-light);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.watermark {
    position: fixed;
    right: 1rem;
    bottom: 1rem;
    opacity: 0.1;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
    pointer-events: none;
    z-index: 1000;
}

@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        padding: 1rem;
    }

    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
        row-gap: 0.75rem;
    }

    .main-container,
    .container {
        padding: 5rem 1.25rem 3rem;
    }

    .btn {
        width: 100%;
    }
}