/* Design System - Based on 16 Principles */

:root {
    /* 3. Precise Colour Psychology (Stripe-Style SaaS) */
    --color-bg-primary: #0A2540; /* Deep Navy */
    --color-bg-secondary: #ffffff; /* White */
    --color-text-primary: #0A2540;
    --color-text-secondary: #425466;
    --color-accent: #635bff; /* Stripe Blue/Purple */
    --color-accent-hover: #0a2540;
    --color-success: #3ecf8e;
    --color-warning: #ffc107;
    --color-danger: #ff3d00;
    
    /* 7. High-Contrast CTA */
    --color-cta-bg: #635bff;
    --color-cta-text: #ffffff;
    
    /* 4. Ultra-Readable Typography */
    --font-family-base: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-size-base: 16px;
    --line-height-base: 1.6;
    --letter-spacing-base: 0.02em;
    
    /* 8. Soft Shadows + Depth */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* 13. Crisp Layout Grids */
    --spacing-unit: 8px;
    --border-radius-sm: 4px;
    --border-radius-md: 8px;
    --border-radius-lg: 12px;
}

body {
    font-family: var(--font-family-base);
    font-size: var(--font-size-base);
    line-height: var(--line-height-base);
    letter-spacing: var(--letter-spacing-base);
    color: var(--color-text-primary);
    background-color: #f6f9fc; /* Light grey for background */
    margin: 0;
    padding: 0;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: calc(var(--spacing-unit) * 2);
    color: var(--color-text-primary);
}

h1 { font-size: 48px; }
h2 { font-size: 36px; }
h3 { font-size: 24px; }

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--color-accent-hover);
}

/* 7. CTA Buttons */
.btn-cta {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background-color: var(--color-cta-bg);
    color: var(--color-cta-text);
    font-weight: 600;
    padding: 12px 24px;
    border-radius: var(--border-radius-md);
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: var(--shadow-md);
    font-size: 16px;
}

.btn-cta:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
    background-color: #5449e8; /* Slightly darker */
}

/* 6. Micro-Animations */
.card {
    background: white;
    border-radius: var(--border-radius-lg);
    padding: calc(var(--spacing-unit) * 4);
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* Form Elements */
input[type="text"],
input[type="email"],
input[type="password"],
input[type="url"] {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid #e3e8ee;
    border-radius: var(--border-radius-md);
    font-size: 16px;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
    box-sizing: border-box; /* Important for width: 100% */
}

input:focus {
    outline: none;
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px rgba(99, 91, 255, 0.1);
}

label {
    display: block;
    font-weight: 500;
    margin-bottom: calc(var(--spacing-unit) * 1);
    color: var(--color-text-secondary);
}

/* Layout Utilities */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 calc(var(--spacing-unit) * 2);
}

.flex-center {
    display: flex;
    align-items: center;
    justify-content: center;
}

.grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: calc(var(--spacing-unit) * 4);
}

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

/* Utility Classes */
.text-center { text-align: center; }
.mb-4 { margin-bottom: calc(var(--spacing-unit) * 2); }
.mt-4 { margin-top: calc(var(--spacing-unit) * 2); }
.w-full { width: 100%; }