/* ============================================
   DFA Code Intelligence — Marketing Site CSS
   ============================================ */

/* --- CSS Variables --- */
:root {
    --gradient-start: #667eea;
    --gradient-end: #764ba2;
    --dark-bg: #0f172a;
    --dark-surface: #1e293b;
    --dark-border: #334155;
    --light-bg: #f8fafc;
    --light-surface: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --text-inverse: #ffffff;
    --grade-a-bg: #d1fae5;
    --grade-a-text: #059669;
    --grade-b-bg: #e0e7ff;
    --grade-b-text: #4f46e5;
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
}

/* --- Gradient Utilities --- */
.gradient-bg {
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
}

.gradient-text {
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* --- Scroll Progress Bar --- */
#scroll-progress {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
    z-index: 9999;
    transition: width 50ms linear;
}

/* --- Navbar --- */
.navbar {
    transition: background var(--transition-normal), box-shadow var(--transition-normal);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.92) !important;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

.navbar.scrolled .nav-link {
    color: var(--text-primary) !important;
}

.navbar.scrolled .nav-logo {
    color: var(--text-primary) !important;
}

.nav-link {
    position: relative;
    transition: color var(--transition-fast);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
    transition: width var(--transition-normal);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

/* --- Mobile Menu --- */
.mobile-menu {
    transform: translateX(100%);
    transition: transform 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

.mobile-menu.open {
    transform: translateX(0);
}

.mobile-overlay {
    opacity: 0;
    pointer-events: none;
    transition: opacity 300ms ease;
}

.mobile-overlay.open {
    opacity: 1;
    pointer-events: auto;
}

/* --- Reveal Animations --- */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1),
                transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Stagger delays for grids */
.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }
.reveal-delay-5 { transition-delay: 0.5s; }
.reveal-delay-6 { transition-delay: 0.6s; }

/* --- Hero Mockup Card --- */
.mockup-card {
    background: var(--light-surface);
    border-radius: 12px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    overflow: hidden;
}

.mockup-card .grade-badge {
    width: 48px;
    height: 48px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.25rem;
    font-family: 'JetBrains Mono', monospace;
}

.grade-a {
    background: var(--grade-a-bg);
    color: var(--grade-a-text);
}

.grade-b {
    background: var(--grade-b-bg);
    color: var(--grade-b-text);
}

/* --- DFA Syntax Coloring --- */
.dfa-code {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    line-height: 1.6;
    background: #0d1117;
    color: #c9d1d9;
    border-radius: 8px;
    overflow-x: auto;
}

.dfa-keyword {
    color: #ff7b72;
    font-weight: 600;
}

.dfa-string {
    color: #a5d6ff;
}

.dfa-var {
    color: #79c0ff;
}

.dfa-comment {
    color: #8b949e;
    font-style: italic;
}

.dfa-directive {
    color: #d2a8ff;
}

.dfa-number {
    color: #ffa657;
}

/* --- Before/After --- */
.before-after-code {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    line-height: 1.7;
}

/* --- FAQ Accordion --- */
.faq-item {
    border-bottom: 1px solid var(--dark-border);
}

.faq-question {
    cursor: pointer;
    transition: color var(--transition-fast);
}

.faq-question:hover {
    color: var(--gradient-start);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1),
                padding 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.faq-answer.open {
    max-height: 500px;
}

.faq-chevron {
    transition: transform 0.3s ease;
}

.faq-chevron.rotated {
    transform: rotate(180deg);
}

/* --- Pipeline Steps Toggle --- */
.pipeline-detail {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.pipeline-detail.open {
    max-height: 800px;
}

/* --- Stats Counter Animation --- */
@keyframes countUp {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.stat-number {
    animation: countUp 0.6s ease-out forwards;
}

/* --- Floating animation for hero visual --- */
@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
}

.float-animation {
    animation: float 6s ease-in-out infinite;
}

/* --- Persona Cards hover --- */
.persona-card {
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.persona-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 40px -12px rgba(0, 0, 0, 0.3);
}

/* --- Trust Pipeline Flow --- */
.pipeline-arrow {
    position: relative;
}

.pipeline-arrow::after {
    content: '';
    position: absolute;
    right: -20px;
    top: 50%;
    transform: translateY(-50%);
    width: 0;
    height: 0;
    border-left: 8px solid var(--gradient-start);
    border-top: 6px solid transparent;
    border-bottom: 6px solid transparent;
}

@media (max-width: 768px) {
    .pipeline-arrow::after {
        right: auto;
        bottom: -20px;
        top: auto;
        transform: translateX(-50%);
        left: 50%;
        border-left: 6px solid transparent;
        border-right: 6px solid transparent;
        border-top: 8px solid var(--gradient-start);
        border-bottom: none;
    }
}

/* --- CTA Button Glow Effect --- */
.cta-glow {
    position: relative;
    overflow: hidden;
}

.cta-glow::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.15) 0%, transparent 60%);
    opacity: 0;
    transition: opacity 0.4s ease;
}

.cta-glow:hover::before {
    opacity: 1;
}

/* --- Smooth scroll offset for anchors --- */
html {
    scroll-padding-top: 80px;
}

/* --- Selection color --- */
::selection {
    background: rgba(102, 126, 234, 0.3);
    color: inherit;
}