*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg-dark: #0a0a0f;
    --bg-section: #111118;
    --bg-card: rgba(255, 255, 255, 0.05);
    --accent-1: #4361ee;
    --accent-2: #7209b7;
    --text: #e8e8f0;
    --text-muted: #9999aa;
    --radius: 16px;
    --radius-sm: 12px;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-dark);
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
}

/* ---- Hero ---- */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 2rem;
    position: relative;
    background: linear-gradient(135deg, var(--bg-dark) 0%, #1a1a2e 100%);
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 600px 400px at 30% 20%, rgba(67, 97, 238, 0.12) 0%, transparent 70%),
        radial-gradient(ellipse 500px 350px at 70% 70%, rgba(114, 9, 183, 0.10) 0%, transparent 70%);
    pointer-events: none;
}

.hero-content {
    position: relative;
    max-width: 720px;
}

.hero h1 {
    font-size: clamp(2.2rem, 6vw, 4rem);
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: 1.25rem;
    background: linear-gradient(135deg, #fff 30%, var(--accent-1) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-sub {
    font-size: clamp(1rem, 2.5vw, 1.25rem);
    color: var(--text-muted);
    margin-bottom: 2.5rem;
    max-width: 560px;
    margin-inline: auto;
}

/* ---- CTA Button ---- */
.cta-btn {
    display: inline-block;
    padding: 0.9rem 2.2rem;
    font-size: 1.05rem;
    font-weight: 600;
    color: #fff;
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
    border: none;
    border-radius: 999px;
    text-decoration: none;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

.cta-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(67, 97, 238, 0.35);
}

/* ---- Hero QR ---- */
.hero-qr {
    margin-top: 1.75rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
}

.hero-qr a {
    display: block;
    background: #fff;
    border-radius: 12px;
    padding: 8px;
    line-height: 0;
    transition: transform 0.2s, box-shadow 0.2s;
}

.hero-qr a:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(67, 97, 238, 0.3);
}

/* ---- Lang Toggle ---- */
.lang-toggle {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
    background: var(--bg-card);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text);
    padding: 0.4rem 0.9rem;
    border-radius: 999px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
    z-index: 10;
}

.lang-toggle:hover {
    background: rgba(255, 255, 255, 0.1);
}

/* ---- Sections ---- */
section {
    padding: 5rem 2rem;
    max-width: 1100px;
    margin: 0 auto;
}

section h2 {
    text-align: center;
    font-size: clamp(1.6rem, 4vw, 2.4rem);
    font-weight: 700;
    margin-bottom: 3rem;
}

/* ---- How It Works ---- */
.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 2rem;
}

.step {
    background: var(--bg-card);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.07);
    border-radius: var(--radius);
    padding: 2rem;
    text-align: center;
}

.step-number {
    width: 48px;
    height: 48px;
    margin: 0 auto 1.2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    font-weight: 700;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
}

.step h3 {
    font-size: 1.15rem;
    margin-bottom: 0.6rem;
}

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

/* ---- Features ---- */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.feature-card {
    background: var(--bg-card);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.07);
    border-radius: var(--radius);
    padding: 1.8rem;
}

.feature-icon {
    font-size: 1.8rem;
    margin-bottom: 0.8rem;
}

.feature-card h3 {
    font-size: 1.05rem;
    margin-bottom: 0.4rem;
}

.feature-card p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* ---- Demo ---- */
.demo-container {
    max-width: 480px;
    margin: 0 auto;
}

.mock-chat {
    background: #1e1e2a;
    border-radius: var(--radius);
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.07);
}

.chat-header {
    display: flex;
    align-items: center;
    gap: 0.7rem;
    padding: 0.9rem 1.2rem;
    background: rgba(255, 255, 255, 0.04);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.chat-avatar {
    font-size: 1.4rem;
}

.chat-name {
    font-weight: 600;
    font-size: 0.95rem;
}

.chat-messages {
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.7rem;
}

.msg {
    padding: 0.7rem 1rem;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    line-height: 1.5;
    max-width: 88%;
    white-space: pre-line;
}

.msg-user {
    background: var(--accent-1);
    align-self: flex-end;
    border-bottom-right-radius: 4px;
}

.msg-bot {
    background: rgba(255, 255, 255, 0.08);
    align-self: flex-start;
    border-bottom-left-radius: 4px;
}

/* ---- Footer ---- */
.footer {
    text-align: center;
    padding: 4rem 2rem 3rem;
    max-width: 1100px;
    margin: 0 auto;
    border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.footer .cta-btn {
    margin-bottom: 1.5rem;
}

.footer-links {
    margin-bottom: 1rem;
}

.footer-link {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s;
}

.footer-link:hover {
    color: var(--text);
}

.footer-tech {
    color: var(--text-muted);
    font-size: 0.8rem;
    opacity: 0.7;
}

/* ---- Fade-in animations ---- */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.7s ease-out, transform 0.7s ease-out;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ---- Responsive ---- */
@media (max-width: 600px) {
    section {
        padding: 3.5rem 1.2rem;
    }

    .steps {
        grid-template-columns: 1fr;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .hero {
        padding: 1.5rem;
    }

    .lang-toggle {
        top: 1rem;
        right: 1rem;
    }
}