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

:root {
    --bg:          #0b0e14;
    --bg-card:     #111620;
    --bg-card-hover: #161c28;
    --border:      #1e2535;
    --text:        #c8cdd5;
    --text-muted:  #6b7486;
    --heading:     #e6eaf0;
    --accent:      #4dacff;
    --accent-dim:  #2a6fb5;
    --accent-glow: rgba(77, 172, 255, .15);
    --radius:      12px;
    --radius-sm:   8px;
    --font-sans:   'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono:   'JetBrains Mono', 'Fira Code', monospace;
}

html { scroll-behavior: smooth; }

body {
    font-family: var(--font-sans);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; transition: color .2s; }
a:hover { color: #7cc4ff; }

/* ── Subtle grid background ── */
.bg-grid {
    position: fixed; inset: 0; z-index: -1; pointer-events: none;
    background-image:
        linear-gradient(rgba(255,255,255,.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,.02) 1px, transparent 1px);
    background-size: 48px 48px;
}

/* ── Navigation ── */
header {
    position: sticky; top: 0; z-index: 100;
    backdrop-filter: blur(16px);
    background: rgba(11, 14, 20, .8);
    border-bottom: 1px solid var(--border);
}

nav {
    max-width: 960px;
    margin: 0 auto;
    padding: 0 1.5rem;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--heading);
    letter-spacing: .04em;
}

.nav-links { display: flex; gap: 1.5rem; }
.nav-links a { color: var(--text-muted); font-size: .9rem; font-weight: 500; }
.nav-links a:hover { color: var(--heading); }

/* ── Buttons ── */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: .65rem 1.5rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: .95rem;
    transition: all .2s;
    cursor: pointer;
    border: none;
    text-decoration: none;
}

.btn-primary {
    background: var(--accent);
    color: var(--bg);
}
.btn-primary:hover {
    background: #7cc4ff;
    color: var(--bg);
    box-shadow: 0 0 24px var(--accent-glow);
}

.btn-secondary {
    background: transparent;
    color: var(--text);
    border: 1px solid var(--border);
}
.btn-secondary:hover {
    border-color: var(--accent-dim);
    color: var(--heading);
}

.btn-sm { padding: .45rem 1rem; font-size: .85rem; }

/* ── Hero ── */
.hero {
    max-width: 960px;
    margin: 0 auto;
    padding: 6rem 1.5rem 4rem;
    text-align: center;
}

.hero h1 {
    font-size: clamp(3rem, 8vw, 5rem);
    font-weight: 700;
    color: var(--heading);
    letter-spacing: -.03em;
    line-height: 1.1;
    margin-bottom: .75rem;
}

.tagline {
    font-size: clamp(1rem, 2.5vw, 1.25rem);
    color: var(--text-muted);
    max-width: 560px;
    margin: 0 auto 2rem;
}

.hero-buttons { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }

/* ── Section shared ── */
section { max-width: 960px; margin: 0 auto; padding: 4rem 1.5rem; }

h2 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--heading);
    text-align: center;
    margin-bottom: .5rem;
}

.section-desc {
    max-width: 640px;
    margin: 0 auto 2.5rem;
    text-align: center;
    color: var(--text-muted);
    line-height: 1.7;
}

.section-desc strong { color: var(--accent); font-weight: 600; }

/* ── Feature Grid ── */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
    gap: 1.25rem;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    transition: border-color .25s, transform .25s;
}
.feature-card:hover {
    border-color: var(--accent-dim);
    transform: translateY(-2px);
}

.feature-icon { font-size: 1.75rem; margin-bottom: .75rem; }

.feature-card h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--heading);
    margin-bottom: .4rem;
}

.feature-card p { font-size: .88rem; color: var(--text-muted); line-height: 1.55; }

/* ── Download Grid ── */
.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 1.25rem;
    max-width: 520px;
    margin: 0 auto 1.5rem;
}

.download-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem 1.5rem;
    transition: border-color .25s, transform .25s;
    text-decoration: none;
}
.download-card:hover {
    border-color: var(--accent-dim);
    transform: translateY(-2px);
}

.download-icon { font-size: 2.5rem; margin-bottom: .75rem; }

.download-card h3 { color: var(--heading); margin-bottom: .25rem; font-size: 1.1rem; }
.download-card p  { color: var(--text-muted); font-size: .85rem; margin-bottom: 1rem; }

.download-note {
    text-align: center;
    font-size: .85rem;
    color: var(--text-muted);
}

/* ── How It Works Steps ── */
.steps-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1.25rem;
}

.step-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    text-align: center;
    transition: border-color .25s, transform .25s;
}
.step-card:hover {
    border-color: var(--accent-dim);
    transform: translateY(-2px);
}

.step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.25rem;
    height: 2.25rem;
    border-radius: 50%;
    background: var(--accent);
    color: var(--bg);
    font-weight: 700;
    font-size: 1rem;
    margin-bottom: .75rem;
}

.step-card h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--heading);
    margin-bottom: .4rem;
}

.step-card p { font-size: .85rem; color: var(--text-muted); line-height: 1.55; }

/* ── FAQ ── */
.faq-list {
    max-width: 720px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: .75rem;
}

.faq-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    transition: border-color .25s;
}
.faq-item:hover,
.faq-item[open] {
    border-color: var(--accent-dim);
}

.faq-item summary {
    padding: 1rem 1.25rem;
    font-weight: 600;
    font-size: .95rem;
    color: var(--heading);
    cursor: pointer;
    list-style: none;
    display: flex;
    align-items: center;
    gap: .75rem;
}

.faq-item summary::before {
    content: '+';
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 1.5rem;
    height: 1.5rem;
    border-radius: 4px;
    background: rgba(77, 172, 255, .1);
    color: var(--accent);
    font-size: 1rem;
    font-weight: 700;
    flex-shrink: 0;
    transition: transform .2s;
}

.faq-item[open] summary::before {
    content: '\2212';
}

.faq-item summary::-webkit-details-marker { display: none; }

.faq-item p {
    padding: 0 1.25rem 1.25rem 3.25rem;
    font-size: .88rem;
    color: var(--text-muted);
    line-height: 1.65;
}

.faq-item p strong { color: var(--accent); font-weight: 600; }

.faq-item p code {
    background: rgba(77, 172, 255, .08);
    color: var(--accent);
    padding: .15em .4em;
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: .85em;
}

/* ── Footer ── */
footer {
    border-top: 1px solid var(--border);
    text-align: center;
    padding: 2rem 1.5rem;
    font-size: .8rem;
    color: var(--text-muted);
}

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

/* ── Mobile ── */
@media (max-width: 600px) {
    nav { padding: 0 1rem; }
    .nav-links { gap: .75rem; font-size: .8rem; }
    .hero { padding: 4rem 1rem 3rem; }
    section { padding: 3rem 1rem; }
    .feature-grid { grid-template-columns: 1fr; }
    .steps-grid { grid-template-columns: 1fr 1fr; }
    .download-grid { grid-template-columns: 1fr; max-width: 300px; }
    .faq-item summary { font-size: .88rem; }
}

@media (max-width: 400px) {
    .steps-grid { grid-template-columns: 1fr; }
}