:root {
    --bg: #0b1020;
    --bg-alt: #0f172a;
    --accent: #38bdf8;
    --accent-soft: rgba(56, 189, 248, 0.22);
    --accent-alt: #f97316;
    --text-main: #e5e7eb;
    --text-muted: #9ca3af;
    --border-soft: rgba(148, 163, 184, 0.7);
    --radius-lg: 18px;
    --shadow-soft: 0 22px 55px rgba(15, 23, 42, 0.9);
}
* { box-sizing: border-box; }
body {
    margin: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "SF Pro Text", sans-serif;
    background:
        radial-gradient(circle at 0% 0%, rgba(56, 189, 248, 0.24), transparent 55%),
        radial-gradient(circle at 100% 100%, rgba(249, 115, 22, 0.26), transparent 55%),
        radial-gradient(circle at 50% 120%, rgba(129, 140, 248, 0.4), transparent 60%),
        var(--bg);
    color: var(--text-main);
    min-height: 100vh;
}
a { color: inherit; text-decoration: none; }
.page { min-height: 100vh; display: flex; flex-direction: column; }
.nav {
    position: sticky;
    top: 0;
    z-index: 50;
    background: linear-gradient(to right, rgba(15, 23, 42, 0.96), rgba(15, 23, 42, 0.9));
    border-bottom: 1px solid rgba(31, 41, 55, 1);
    box-shadow: 0 18px 40px rgba(15, 23, 42, 0.8);
}
.nav-inner {
    max-width: 1040px;
    margin: 0 auto;
    padding: 12px 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}
.logo {
    font-weight: 650;
    letter-spacing: 0.04em;
    font-size: 1.05rem;
    align-items: center;
    gap: 8px;
    color: #e5e7eb;
}
.logo::before {
    content: "";
    width: 9px;
    height: 9px;
    border-radius: 999px;
    background: radial-gradient(circle at 30% 30%, #e0f2fe, #38bdf8);
    box-shadow: 0 0 16px rgba(56, 189, 248, 0.9);
}
.nav-links {
    display: flex;
    gap: 18px;
    font-size: 0.9rem;
    color: #e5e7eb;
}
.nav-links a {
    padding: 6px 0;
    position: relative;
}
.nav-links a::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: -2px;
    width: 0;
    height: 2px;
    border-radius: 999px;
    background: linear-gradient(to right, #38bdf8, #f97316);
    transition: width 0.18s ease-out;
}
.nav-links a:hover::after { width: 100%; }
.main {
    flex: 1;
    max-width: 1040px;
    margin: 0 auto;
    padding: 32px 20px 46px;
}
.hero-grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: 24px;
    align-items: start;
}
.hero-text h1 {
    font-size: clamp(2.3rem, 3.4vw, 2.9rem);
    line-height: 1.05;
    letter-spacing: -0.04em;
    margin: 0 0 14px;
    color: #f9fafb;
}
.hero-logo-wrap {
    margin-bottom: 10px;
    display: flex;
    justify-content: center;
}
.hero-logo {
    height: 300px;
    display: block;
}
.hero-pill-wrap {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
}
.hero-pill {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 4px 10px;
    border-radius: 999px;
    border: 1px solid rgba(56, 189, 248, 0.6);
    background: radial-gradient(circle at top left, rgba(56, 189, 248, 0.3), transparent 55%);
    color: #e0f2fe;
    font-size: 0.7rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    margin-bottom: 12px;
    margin-right: 8px;
}
.hero-pill-dot {
    width: 6px;
    height: 6px;
    border-radius: 999px;
    background: #22c55e;
}
.hero-sub {
    color: #d1d5db;
    font-size: 0.95rem;
    margin-bottom: 18px;
}
.app-page-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 20px;
    justify-content: center;
}
.app-page-icon {
    width: 256px;
    height: 256px;
    border-radius: 8px;
}
.app-screenshots {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin: 10px 0 40px;
    justify-content: center;
}
.app-screenshot {
    height: 480px;
    width: auto;
}
.hero-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 20px;
}
.hero-tag {
    font-size: 0.78rem;
    padding: 4px 9px;
    border-radius: 999px;
    border: 1px solid rgba(148, 163, 184, 0.7);
    background: rgba(15, 23, 42, 0.9);
    color: #e5e7eb;
}
.hero-cta {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 18px;
    justify-content: center;
}
.btn-vigilance, .btn-stroop, .btn-nback {
    border-radius: 999px;
    padding: 8px 14px;
    font-size: 0.9rem;
    border: 1px solid transparent;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 7px;
    cursor: pointer;
    background: none;
    color: inherit;
}
.btn-vigilance {
    background: linear-gradient(135deg, #22c55e, #38bdf8);
    color: #0f172a;
    font-weight: 600;
    box-shadow: 0 16px 34px rgba(34, 197, 94, 0.4);
}
.btn-stroop {
    background: linear-gradient(135deg, #ff00ff 0%, #ff40ff 18%, #52f6ff 55%, #00ffff 100%);
    background-repeat: no-repeat;
    background-size: 130% 130%;
    color: #0f172a;
    font-weight: 600;
    box-shadow: 0 16px 34px rgba(82, 246, 255, 0.35);
}
.btn-nback {
    background: linear-gradient(135deg, #F38A83, #F7D5B1);
    color: #0f172a;
    font-weight: 600;
    box-shadow: 0 16px 34px rgba(243, 138, 131, 0.45);
}
.btn-small {
    padding: 6px 10px;
    font-size: 0.8rem;
}
.trust-note {
    font-size: 0.8rem;
    color: #cbd5f5;
}
.hero-card-wrap {
    grid-column: 1 / -1;
}
.hero-card {
    border-radius: var(--radius-lg);
    background:
        radial-gradient(circle at 0% 0%, rgba(56, 189, 248, 0.20), transparent 55%),
        radial-gradient(circle at 100% 100%, rgba(249, 115, 22, 0.18), transparent 55%),
        var(--bg-alt);
    border: 1px solid rgba(15, 23, 42, 0.9);
    border-top: 4px solid var(--accent);
    box-shadow: var(--shadow-soft);
    padding: 18px 16px 34px;
    display: flex;
    flex-direction: column;
    gap: 14px;
    transition: background 0.25s ease-out, border-color 0.25s ease-out, border-top-color 0.25s ease-out;
}
.hero-card.stroop-theme {
    border-color: rgba(147, 51, 234, 0.9);
    border-top-color: #ff00ff;
    background: radial-gradient(circle at 0% 0%, rgba(255, 0, 255, 0.3), transparent 55%),
                radial-gradient(circle at 100% 100%, rgba(0, 255, 255, 0.26), transparent 55%),
                linear-gradient(to bottom right, #020617, #020617);
}
.hero-card.vigilance-theme {
    border-color: rgba(0, 203, 243, 0.9);
    border-top-color: #00cbf3;
    background: radial-gradient(circle at 0% 0%, rgba(0, 203, 243, 0.30), transparent 55%),
                radial-gradient(circle at 100% 100%, rgba(0, 243, 158, 0.26), transparent 55%),
                linear-gradient(to bottom right, #020617, #020617);
}
.hero-card.nback-theme {
    border-color: #F38A83;
    border-top-color: #F7D5B1;
    background: radial-gradient(circle at 0% 0%, rgba(243, 138, 131, 0.30), transparent 55%),
                radial-gradient(circle at 100% 100%, rgba(247, 213, 177, 0.26), transparent 55%),
                linear-gradient(to bottom right, #020617, #020617);
}
.carousel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 4px;
}
.carousel-header span {
    font-size: 0.78rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: #cbd5f5;
}
.carousel-dots {
    display: inline-flex;
    gap: 4px;
}
.carousel-dots button {
    width: 7px;
    height: 7px;
    border-radius: 999px;
    border: none;
    background: rgba(148, 163, 184, 0.7);
    padding: 0;
    cursor: pointer;
    opacity: 0.7;
}
.carousel-dots button.active {
    width: 18px;
    opacity: 1;
    background: linear-gradient(to right, #38bdf8, #f97316);
}
.carousel-track {
    position: relative;
    min-height: 170px;
}
.carousel-slide {
    position: absolute;
    inset: 0;
    opacity: 0;
    transform: translateY(6px);
    pointer-events: none;
    transition: opacity 0.2s ease-out, transform 0.2s ease-out;
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.carousel-slide.active {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}
.carousel-slide.stroop-slide {
    /* no extra background, theme applied on hero-card */
}
.carousel-slide.vigilance-slide {
    /* no extra background, theme applied on hero-card */
}
.badge-platforms {
    display: flex;
    flex-wrap: wrap;
    gap: 4px;
    font-size: 0.7rem;
    color: #cbd5f5;
    margin-bottom: 12px;
}
.badge-platform {
    padding: 3px 7px;
    border-radius: 999px;
    background: rgba(15, 23, 42, 0.9);
    border: 1px solid rgba(148, 163, 184, 0.8);
}
.app-title {
    font-weight: 600;
    font-size: 1rem;
    margin-bottom: 2px;
    color: #f9fafb;
}
.app-sub {
    font-size: 0.88rem;
    color: #e5e7eb;
    margin-bottom: 6px;
}
.app-meta {
    font-size: 0.75rem;
    color: #cbd5f5;
}
.app-meta strong { color: #ffffff; }
.download-row {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin: 20px 0;
}
.btn-ghost {
    border-radius: 999px;
    border: 1px solid rgba(148, 163, 184, 0.9);
    background: rgba(15, 23, 42, 0.95);
    color: #e5e7eb;
    font-size: 0.78rem;
    padding: 5px 9px;
}
.section {
    margin-top: 40px;
    padding: 22px 20px 22px;
    border-radius: 18px;
    border: 1px solid rgba(30, 64, 175, 0.7);
    border-top: 4px solid var(--accent);
    background: radial-gradient(circle at 0% 0%, rgba(56, 189, 248, 0.24), transparent 55%),
                linear-gradient(to bottom right, #020617, #020617);
    box-shadow: 0 18px 52px rgba(15, 23, 42, 0.9);
}
.section + .section {
    margin-top: 32px;
}
.section:nth-of-type(even) {
    border-top-color: var(--accent-alt);
    background: radial-gradient(circle at 100% 0%, rgba(249, 115, 22, 0.2), transparent 55%),
                linear-gradient(to bottom right, #020617, #020617);
}
.stroop-page .section {
    border-color: rgba(147, 51, 234, 0.9);
    border-top-color: #ff00ff;
    background: radial-gradient(circle at 0% 0%, rgba(255, 0, 255, 0.3), transparent 55%),
                radial-gradient(circle at 100% 100%, rgba(0, 255, 255, 0.26), transparent 55%),
                linear-gradient(to bottom right, #020617, #020617);
}
.stroop-page h1 {
    text-align: center;
}
.stroop-page .feature-card {
    background: rgba(17, 24, 39, 0.98);
    border-color: rgba(168, 85, 247, 0.8);
}
.stroop-page .hero-sub,
.stroop-page .trust-note {
    color: #e0e7ff;
}
.vigilance-page .section {
    border-color: rgba(0, 203, 243, 0.9);
    border-top-color: #00cbf3;
    background: radial-gradient(circle at 0% 0%, rgba(0, 203, 243, 0.30), transparent 55%),
                radial-gradient(circle at 100% 100%, rgba(0, 243, 158, 0.26), transparent 55%),
                linear-gradient(to bottom right, #020617, #020617);
}
.vigilance-page h1 {
    text-align: center;
}
.vigilance-page .feature-card {
    background: rgba(15, 23, 42, 0.98);
    border-color: rgba(0, 243, 158, 0.8);
}
.nback-page .section {
    border-color: #F38A83;
    border-top-color: #F7D5B1;
    background: radial-gradient(circle at 0% 0%, rgba(243, 138, 131, 0.30), transparent 55%),
                radial-gradient(circle at 100% 100%, rgba(247, 213, 177, 0.26), transparent 55%),
                linear-gradient(to bottom right, #020617, #020617);
}
.nback-page h1 {
    text-align: center;
}
.nback-page .feature-card {
    background: rgba(17, 24, 39, 0.98);
    border-color: rgba(243, 138, 131, 0.85);
}
.section h2 {
    margin-top: 0;
    font-size: 1.15rem;
    margin-bottom: 10px;
}
.section-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
    gap: 16px;
}
.feature-card {
    border-radius: 14px;
    padding: 12px 12px 12px;
    background: rgba(15, 23, 42, 0.96);
    border: 1px solid rgba(30, 64, 175, 0.8);
    font-size: 0.88rem;
}
.downloads-card {
    background: rgba(15, 23, 42, 0.98);
    border-color: rgba(148, 163, 184, 0.9);
}
.platform-logo-row {
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.platform-logo-row img {
    height: 34px;
    width: auto;
}
.feature-card h3 {
    margin: 0 0 6px;
    font-size: 0.95rem;
}
.feature-card p {
    margin: 0;
    color: var(--text-muted);
}
.testimonial {
    display: grid;
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
    gap: 18px;
    align-items: flex-start;
}
.testimonial-photo {
    margin-top: 0;
    max-width: 80px;
    border-radius: 999px;
    display: block;
}
.testimonial-main {
    display: flex;
    align-items: center;
    gap: 12px;
}
.contact-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 1.3fr);
    gap: 18px;
    align-items: flex-start;
}
.contact-copy {
    max-width: 520px;
}
.contact-form-wrap {
    width: 100%;
}
.contact-form-wrap fieldset {
    border-radius: 14px;
    border: 1px solid rgba(148, 163, 184, 0.6);
    padding: 16px 14px 14px;
    background: rgba(15, 23, 42, 0.9);
}
.contact-form-wrap input,
.contact-form-wrap textarea {
    width: 100%;
    box-sizing: border-box;
    padding: 9px 10px;
    font-size: 0.9rem;
}
.contact-form-wrap fieldset > div {
    margin-bottom: 10px;
}
.contact-cta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}
.contact-success,
.contact-error {
    border-radius: 14px;
    padding: 14px 14px 12px;
    background: rgba(15, 23, 42, 0.96);
    border: 1px solid rgba(30, 64, 175, 0.8);
    box-shadow: 0 16px 40px rgba(15, 23, 42, 0.85);
}
.contact-success {
    border-color: rgba(34, 197, 94, 0.85);
}
.contact-error {
    border-color: rgba(248, 113, 113, 0.9);
}
.contact-success-title,
.contact-error-title {
    margin: 0 0 4px;
    font-size: 0.98rem;
}
.contact-success-text,
.contact-error-text {
    margin: 0;
    font-size: 0.9rem;
    color: var(--text-muted);
}
.quote {
    font-size: 0.95rem;
    color: #e5e7eb;
    border-left: 2px solid rgba(56, 189, 248, 0.6);
    padding-left: 10px;
    margin-bottom: 8px;
}
.quote-attrib {
    font-size: 0.85rem;
    color: #9ca3af;
}
.paper-link a {
    font-size: 0.85rem;
    color: #38bdf8;
    text-decoration: underline;
}
.footer {
    border-top: 1px solid rgba(15, 23, 42, 1);
    background: #020617;
    padding: 14px 0 18px;
}
.footer-inner {
    max-width: 1040px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    font-size: 0.8rem;
    color: #9ca3af;
}
.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}
@media (max-width: 840px) {
    .testimonial {
        grid-template-columns: minmax(0, 1fr);
    }
}
@media (max-width: 640px) {
    .nav-inner { flex-direction: column; align-items: flex-start; }
    .nav-links { flex-wrap: wrap; row-gap: 6px; }
    .main { padding-top: 20px; }
    .section { padding: 16px 14px 16px; }
    .contact-grid { grid-template-columns: minmax(0, 1fr); }
    .app-screenshot {
        max-width: 100%;
        height: auto;
    }
    /* Mobile-specific tweaks for hero card and carousel */
    .hero-card {
        padding: 16px 14px 22px;
    }
    .carousel-track {
        min-height: 240px;
    }
}