/* Landing Page — Light Theme */

:root {
    --bg: #ffffff;
    --bg-page: #f9fafb;
    --bg-card: #ffffff;
    --border: #e5e7eb;
    --text: #111827;
    --text-muted: #6b7280;
    --text-dim: #9ca3af;
    --accent: #6366f1;
    --accent-hover: #4f46e5;
    --accent-dim: rgba(99, 102, 241, 0.06);
    --accent-light: rgba(99, 102, 241, 0.1);
    --radius: 12px;
}

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

html {
    scroll-behavior: smooth;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg);
    color: var(--text);
    font-size: 15px;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* Nav */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 50;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
}

.nav-inner {
    max-width: 1100px;
    margin: 0 auto;
    padding: 14px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-weight: 700;
    font-size: 16px;
    color: var(--text);
    text-decoration: none;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 24px;
}

.nav-links a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 13px;
    font-weight: 500;
    transition: color 0.15s;
}

.nav-links a:hover { color: var(--text); }

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 8px 18px;
    border-radius: 8px;
    font-family: inherit;
    font-size: 13px;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.15s;
    border: none;
}

.btn-primary {
    background: var(--accent);
    color: white;
    box-shadow: 0 1px 3px rgba(99, 102, 241, 0.3);
}
.btn-primary:hover { background: var(--accent-hover); transform: translateY(-1px); box-shadow: 0 4px 12px rgba(99, 102, 241, 0.25); }

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

.btn-lg { padding: 12px 28px; font-size: 14px; border-radius: 10px; }

/* Hero */
.hero {
    max-width: 1100px;
    margin: 0 auto;
    padding: 140px 24px 80px;
    text-align: center;
}

.hero-badge {
    display: inline-block;
    padding: 5px 14px;
    background: var(--accent-dim);
    border: 1px solid var(--accent-light);
    border-radius: 99px;
    font-size: 12px;
    font-weight: 600;
    color: var(--accent);
    margin-bottom: 24px;
}

.hero h1 {
    font-size: clamp(36px, 6vw, 60px);
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.03em;
    margin-bottom: 20px;
    color: var(--text);
}

.hero-sub {
    max-width: 540px;
    margin: 0 auto 32px;
    font-size: 17px;
    color: var(--text-muted);
    line-height: 1.7;
}

.hero-actions {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 64px;
}

/* Chat Preview */
.hero-visual {
    max-width: 600px;
    margin: 0 auto;
}

.chat-preview {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    box-shadow: 0 8px 40px rgba(99, 102, 241, 0.08), 0 1px 3px rgba(0,0,0,0.05);
}

.preview-msg {
    display: flex;
    gap: 10px;
    align-items: flex-start;
}

.preview-msg.user { justify-content: flex-end; }

.preview-avatar {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--accent-dim);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 13px;
    flex-shrink: 0;
}

.preview-bubble {
    padding: 10px 14px;
    border-radius: 14px;
    font-size: 13px;
    line-height: 1.5;
    max-width: 80%;
}

.preview-msg.ai .preview-bubble {
    background: var(--bg-page);
    border: 1px solid var(--border);
    color: var(--text);
    border-top-left-radius: 4px;
}

.preview-msg.user .preview-bubble {
    background: var(--accent);
    color: white;
    border-top-right-radius: 4px;
}

/* Sections */
.features { padding: 80px 0; background: var(--bg-page); }
.how { padding: 80px 0; }
.cta { padding: 80px 0; background: var(--bg-page); text-align: center; }

.section-inner {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

.section-label {
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--accent);
    margin-bottom: 12px;
}

.features h2,
.how h2,
.cta h2 {
    font-size: clamp(28px, 4vw, 38px);
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 48px;
    color: var(--text);
}

.cta p {
    color: var(--text-muted);
    font-size: 16px;
    margin-bottom: 28px;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 16px;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px;
    transition: all 0.2s;
    box-shadow: 0 1px 2px rgba(0,0,0,0.03);
}

.feature-card:hover { border-color: var(--accent); box-shadow: 0 4px 16px rgba(99,102,241,0.08); transform: translateY(-2px); }

.feature-icon { font-size: 24px; margin-bottom: 14px; }

.feature-card h3 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text);
}

.feature-card p {
    color: var(--text-muted);
    font-size: 13px;
    line-height: 1.6;
}

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

.step { padding: 24px; }

.step-num {
    font-size: 32px;
    font-weight: 800;
    color: var(--accent);
    opacity: 0.4;
    margin-bottom: 12px;
    letter-spacing: -0.02em;
}

.step h3 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--text);
}

.step p {
    color: var(--text-muted);
    font-size: 13px;
}

/* Footer */
.footer {
    border-top: 1px solid var(--border);
    padding: 20px 0;
}

.footer-inner {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    justify-content: space-between;
    font-size: 12px;
    color: var(--text-dim);
}

.footer a { color: var(--accent); text-decoration: none; }
.footer a:hover { text-decoration: underline; }

/* Mobile */
@media (max-width: 640px) {
    .nav-links a:not(.btn) { display: none; }
    .hero { padding: 120px 20px 60px; }
    .hero-actions { flex-direction: column; align-items: center; }
    .feature-grid { grid-template-columns: 1fr; }
    .steps { grid-template-columns: 1fr; }
}