/* ============================================
   Nerva — Landing Page Styles
   nerva.ai | The nervous system of AI-native engineering
   ============================================ */

/* --- Reset & Base --- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --color-bg: #0a0a0f;
    --color-surface: #12121a;
    --color-surface-2: #1a1a26;
    --color-border: #2a2a3a;
    --color-text: #e8e8f0;
    --color-text-muted: #8888a0;
    --color-primary: #6c5ce7;
    --color-primary-light: #a29bfe;
    --color-accent: #00cec9;
    --color-accent-light: #55efc4;
    --color-danger: #ff6b6b;
    --color-warning: #fdcb6e;
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --font-mono: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
    --max-width: 1120px;
    --radius: 12px;
    --radius-sm: 8px;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    font-size: 16px;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* --- Navigation --- */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(10, 10, 15, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--color-border);
}

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.logo {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-text);
    text-decoration: none;
    letter-spacing: -0.02em;
}

.logo-nerva {
    color: var(--color-primary-light);
    font-weight: 700;
}

.logo-tm {
    font-size: 0.6em;
    vertical-align: super;
    color: var(--color-text-muted);
}

.nav-cta {
    display: inline-block;
    padding: 8px 20px;
    background: var(--color-primary);
    color: #fff;
    text-decoration: none;
    font-size: 0.875rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
    transition: background 0.2s, transform 0.2s;
}

.nav-cta:hover {
    background: var(--color-primary-light);
    color: var(--color-bg);
    transform: translateY(-1px);
}

/* --- Hero --- */
.hero {
    padding: 140px 0 80px;
    text-align: center;
    background:
        radial-gradient(ellipse 60% 50% at 50% 0%, rgba(108, 92, 231, 0.12) 0%, transparent 70%),
        var(--color-bg);
}

.hero-badge {
    display: inline-block;
    padding: 6px 16px;
    background: var(--color-surface-2);
    border: 1px solid var(--color-border);
    border-radius: 50px;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--color-accent);
    letter-spacing: 0.05em;
    text-transform: uppercase;
    margin-bottom: 24px;
}

.hero h1 {
    font-size: clamp(2.2rem, 5vw, 3.6rem);
    font-weight: 800;
    line-height: 1.15;
    letter-spacing: -0.03em;
    margin-bottom: 20px;
    color: #fff;
}

.highlight {
    background: linear-gradient(135deg, var(--color-primary-light), var(--color-accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.highlight-red {
    color: var(--color-danger);
    -webkit-text-fill-color: var(--color-danger);
}

.hero-sub {
    font-size: 1.15rem;
    color: var(--color-text-muted);
    max-width: 640px;
    margin: 0 auto 36px;
    line-height: 1.7;
}

.hero-sub strong {
    color: var(--color-text);
}

/* --- Email Form --- */
.email-form .form-group {
    display: flex;
    gap: 0;
    max-width: 480px;
    margin: 0 auto;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    overflow: hidden;
    transition: border-color 0.2s;
}

.email-form .form-group:focus-within {
    border-color: var(--color-primary);
}

.email-form input[type="email"] {
    flex: 1;
    padding: 14px 18px;
    background: transparent;
    border: none;
    color: var(--color-text);
    font-size: 1rem;
    font-family: var(--font-sans);
    outline: none;
    min-width: 0;
}

.email-form input[type="email"]::placeholder {
    color: var(--color-text-muted);
}

.email-form button {
    padding: 14px 24px;
    background: var(--color-primary);
    color: #fff;
    border: none;
    font-size: 0.95rem;
    font-weight: 600;
    font-family: var(--font-sans);
    cursor: pointer;
    transition: background 0.2s;
    white-space: nowrap;
}

.email-form button:hover {
    background: var(--color-primary-light);
    color: var(--color-bg);
}

.email-form button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.form-hint {
    font-size: 0.8rem;
    color: var(--color-text-muted);
    margin-top: 10px;
    text-align: center;
}

.form-success {
    color: var(--color-accent) !important;
    font-weight: 500;
}

/* --- Hero Proof Bar --- */
.hero-proof {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 32px;
    margin-top: 48px;
    padding-top: 32px;
    border-top: 1px solid var(--color-border);
    max-width: 520px;
    margin-left: auto;
    margin-right: auto;
}

.proof-item {
    text-align: center;
}

.proof-number {
    display: block;
    font-size: 1.4rem;
    font-weight: 800;
    color: #fff;
    font-family: var(--font-mono);
    letter-spacing: -0.02em;
}

.proof-label {
    display: block;
    font-size: 0.75rem;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin-top: 2px;
}

.proof-divider {
    width: 1px;
    height: 32px;
    background: var(--color-border);
}

/* --- Sections --- */
.section {
    padding: 96px 0;
}

.section h2 {
    font-size: clamp(1.6rem, 3.5vw, 2.4rem);
    font-weight: 800;
    letter-spacing: -0.02em;
    text-align: center;
    margin-bottom: 12px;
    color: #fff;
}

.section-sub {
    font-size: 1.05rem;
    color: var(--color-text-muted);
    text-align: center;
    max-width: 560px;
    margin: 0 auto 48px;
    line-height: 1.7;
}

/* --- Problem Section --- */
.problem {
    background: var(--color-surface);
}

.pain-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.pain-card {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 32px 28px;
    transition: border-color 0.2s, transform 0.2s;
}

.pain-card:hover {
    border-color: var(--color-danger);
    transform: translateY(-2px);
}

.pain-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 107, 107, 0.1);
    color: var(--color-danger);
    border-radius: 10px;
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 16px;
}

.pain-card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 8px;
    color: #fff;
}

.pain-card p {
    font-size: 0.95rem;
    color: var(--color-text-muted);
    line-height: 1.6;
}

/* --- Score / Maturity Levels --- */
.score {
    background: var(--color-bg);
}

.levels {
    max-width: 640px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.level {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    padding: 20px 24px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    transition: border-color 0.2s, transform 0.2s;
}

.level:hover {
    transform: translateX(4px);
}

.level-highlight {
    border-color: var(--color-accent);
    background: linear-gradient(135deg, rgba(0, 206, 201, 0.05), rgba(108, 92, 231, 0.05));
}

.level-badge {
    flex-shrink: 0;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
    font-size: 0.85rem;
    font-weight: 800;
    font-family: var(--font-mono);
    color: #fff;
}

.l1 { background: #636e72; }
.l2 { background: #e17055; }
.l3 { background: #fdcb6e; color: #2d3436; }
.l4 { background: var(--color-primary); }
.l5 { background: linear-gradient(135deg, var(--color-accent), var(--color-primary-light)); }

.level-content h3 {
    font-size: 1rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 4px;
}

.level-content p {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    line-height: 1.5;
}

/* --- How It Works --- */
.how {
    background: var(--color-surface);
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 32px;
}

.step {
    text-align: center;
    padding: 32px 24px;
}

.step-number {
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    color: #fff;
    font-size: 1.3rem;
    font-weight: 800;
    font-family: var(--font-mono);
    border-radius: 50%;
    margin: 0 auto 20px;
}

.step h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 10px;
}

.step p {
    font-size: 0.95rem;
    color: var(--color-text-muted);
    line-height: 1.6;
}

/* --- Services Grid --- */
.services {
    background: var(--color-bg);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
}

.service-item {
    padding: 28px 24px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    border-left: 3px solid var(--color-accent);
    transition: border-color 0.2s, transform 0.2s;
}

.service-item:hover {
    border-color: var(--color-accent);
    transform: translateY(-2px);
}

.service-item h3 {
    font-size: 0.95rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 8px;
}

.service-item p {
    font-size: 0.88rem;
    color: var(--color-text-muted);
    line-height: 1.6;
}

/* --- Results --- */
.results {
    background: var(--color-bg);
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.result-card {
    text-align: center;
    padding: 40px 28px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    transition: border-color 0.2s, transform 0.2s;
}

.result-card:hover {
    border-color: var(--color-primary);
    transform: translateY(-2px);
}

.result-metric {
    font-size: 2.8rem;
    font-weight: 900;
    font-family: var(--font-mono);
    background: linear-gradient(135deg, var(--color-primary-light), var(--color-accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.03em;
    margin-bottom: 4px;
}

.result-label {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--color-text);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin-bottom: 12px;
}

.result-card p {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    line-height: 1.6;
}

/* --- Insight Section --- */
.insight {
    background: var(--color-bg);
    padding: 80px 0;
}

.insight-container {
    max-width: 720px;
    text-align: center;
}

.insight-quote {
    font-size: 1.25rem;
    line-height: 1.7;
    color: var(--color-text);
    border-left: 3px solid var(--color-primary);
    padding: 24px 32px;
    margin: 32px auto;
    background: var(--color-surface);
    border-radius: 0 var(--radius) var(--radius) 0;
    text-align: left;
}

.insight-quote strong {
    color: var(--color-danger);
}

.insight-follow {
    font-size: 1.15rem;
    color: var(--color-text-muted);
    margin-top: 24px;
}

.insight-follow strong {
    color: #fff;
}

/* --- Pillar Grid --- */
.pillars {
    background: var(--color-surface);
}

.pillar-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 16px;
}

.pillar-card {
    padding: 24px 20px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    transition: border-color 0.2s, transform 0.2s;
}

.pillar-card:hover {
    border-color: var(--color-primary);
    transform: translateY(-2px);
}

.pillar-label {
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--color-accent);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 6px;
}

.pillar-card h3 {
    font-size: 0.95rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 6px;
}

.pillar-card p {
    font-size: 0.82rem;
    color: var(--color-text-muted);
    line-height: 1.5;
}

/* --- Level Target Tag --- */
.level-target {
    border-color: var(--color-warning);
    background: linear-gradient(135deg, rgba(253, 203, 110, 0.06), rgba(108, 92, 231, 0.04));
}

.level-tag {
    display: inline-block;
    padding: 2px 8px;
    background: var(--color-warning);
    color: #2d3436;
    font-size: 0.65rem;
    font-weight: 700;
    border-radius: 4px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    vertical-align: middle;
    margin-left: 6px;
}

/* --- Audience --- */
.audience {
    background: var(--color-surface);
}

.audience-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.audience-card {
    padding: 32px 28px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    transition: border-color 0.2s;
}

.audience-card:hover {
    border-color: var(--color-primary);
}

.audience-card h3 {
    font-size: 1.05rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 10px;
}

.audience-card p {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    line-height: 1.6;
}

/* --- CTA Section --- */
.cta {
    background:
        radial-gradient(ellipse 60% 50% at 50% 100%, rgba(108, 92, 231, 0.12) 0%, transparent 70%),
        var(--color-bg);
    padding: 96px 0 120px;
    text-align: center;
}

/* --- Footer --- */
.footer {
    padding: 40px 0;
    border-top: 1px solid var(--color-border);
    background: var(--color-bg);
}

.footer-inner {
    text-align: center;
}

.footer-brand {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.footer-copy {
    font-size: 0.8rem;
    color: var(--color-text-muted);
    margin-bottom: 4px;
}

.footer-tagline {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    font-style: italic;
}

/* --- Responsive --- */
@media (max-width: 768px) {
    .hero {
        padding: 120px 0 60px;
    }

    .hero-proof {
        gap: 20px;
    }

    .proof-number {
        font-size: 1.1rem;
    }

    .section {
        padding: 64px 0;
    }

    .pain-grid,
    .steps,
    .results-grid,
    .audience-grid,
    .pillar-grid,
    .services-grid {
        grid-template-columns: 1fr;
    }

    .email-form .form-group {
        flex-direction: column;
        border-radius: var(--radius);
    }

    .email-form input[type="email"] {
        padding: 14px 16px;
        border-bottom: 1px solid var(--color-border);
    }

    .email-form button {
        padding: 14px 16px;
        border-radius: 0;
    }

    .levels {
        gap: 12px;
    }

    .level {
        padding: 16px 18px;
        gap: 14px;
    }

    .level-badge {
        width: 38px;
        height: 38px;
        font-size: 0.75rem;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 1.8rem;
    }

    .hero-sub {
        font-size: 1rem;
    }

    .nav-cta {
        padding: 6px 14px;
        font-size: 0.8rem;
    }
}