/* ===========================================
   Delta Global Styles
   Design Token System & Shared Components
   =========================================== */

:root {
    /* Colors */
    --ink-color: #000000;
    --ink-muted: #4a4a4a;  /* Updated from #555555 for AAA contrast (7:1) */
    --bg-color: #ffffff;
    --bg-card: #ffffff;
    --bg-subtle: #fafafa;
    --bg-hover: #f5f5f5;
    --bg-hover-dark: #f0f0f0;
    --border-color: #000000;
    --border-light: #e0e0e0;
    --border-subtle: rgba(0, 0, 0, 0.05);

    /* Dark backgrounds */
    --dark-1: #0f0f0f;
    --dark-2: #1a1a1a;
    --dark-3: #2d2d2d;

    /* Typography */
    --font-ui: Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
    --font-prose: Georgia, 'Times New Roman', serif;

    --font-size-xs: 10px;
    --font-size-sm: 11px;
    --font-size-base: 13px;
    --font-size-md: 14px;
    --font-size-lg: 15px;
    --font-size-xl: 28px;
    --font-size-2xl: 38px;
    --font-size-3xl: 48px;

    --line-height-tight: 1.2;
    --line-height-base: 1.7;
    --line-height-relaxed: 1.8;

    --letter-spacing-tight: -0.02em;
    --letter-spacing-label: 0.1em;      /* For labels, category numbers */
    --letter-spacing-header: 0.15em;    /* For section headers, hero labels */

    /* Spacing Scale */
    --space-xs: 10px;
    --space-sm: 20px;
    --space-md: 30px;
    --space-lg: 50px;
    --space-xl: 80px;
    --space-2xl: 100px;

    /* Layout */
    --content-width: 1000px;
    --content-width-wide: 1100px;
    --padding-page: 60px;
    --padding-page-tablet: 40px;
    --padding-page-mobile: 20px;

    /* Borders */
    --border-radius-sm: 3px;
    --border-radius-md: 4px;
    --border-radius-lg: 8px;
    --border-radius-xl: 12px;

    /* Shadows */
    --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 25px 50px -12px rgba(0, 0, 0, 0.6);

    /* Transitions */
    --transition-fast: 0.15s;
    --transition-base: 0.2s;
    --transition-slow: 0.3s;
}

/* ===========================================
   Focus States - Keyboard Navigation
   =========================================== */

a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
[tabindex]:focus-visible {
    outline: 2px solid var(--ink-color);
    outline-offset: 2px;
}

/* Remove outline for mouse users */
a:focus:not(:focus-visible),
button:focus:not(:focus-visible) {
    outline: none;
}

/* ===========================================
   CTA Button Styles
   =========================================== */

.cta-button {
    display: inline-block;
    padding: 12px 24px;
    background: var(--ink-color);
    color: var(--bg-color);
    text-decoration: none;
    border-radius: var(--border-radius-md);
    font-size: var(--font-size-base);
    font-weight: bold;
    text-transform: uppercase;
    letter-spacing: var(--letter-spacing-label);
    transition: background var(--transition-base), transform var(--transition-base);
    border: none;
    cursor: pointer;
    font-family: var(--font-ui);
}

.cta-button:hover {
    background: #333;
    transform: translateY(-1px);
}

.cta-button:active {
    transform: translateY(0);
}

.cta-button-outline {
    background: transparent;
    border: 1px solid var(--ink-color);
    color: var(--ink-color);
}

.cta-button-outline:hover {
    background: var(--ink-color);
    color: var(--bg-color);
}

/* Light variant for dark backgrounds */
.cta-button-light {
    background: var(--bg-color);
    color: var(--ink-color);
}

.cta-button-light:hover {
    background: var(--bg-hover);
}

/* ===========================================
   Dark Section Gradients
   =========================================== */

.hero-gradient {
    background: linear-gradient(135deg, var(--dark-1) 0%, var(--dark-2) 50%, var(--dark-1) 100%);
}

.feature-gradient {
    background: linear-gradient(180deg, var(--dark-2) 0%, var(--dark-1) 100%);
}

.section-gradient {
    background: linear-gradient(135deg, var(--dark-2) 0%, var(--dark-3) 50%, var(--dark-2) 100%);
}

/* ===========================================
   Mobile Navigation Fix
   =========================================== */

@media (max-width: 400px) {
    .header-nav {
        font-size: 11px;
        gap: 15px;
    }
}