:root {
    --color-background-primary: #ffffff;
    --color-background-secondary: #f8fafc;
    --color-background-info: #e0f2fe;
    --color-border-tertiary: #cbd5e1;
    --color-border-info: #0ea5e9;
    --color-text-primary: #0f172a;
    --color-text-secondary: #475569;
    --color-text-tertiary: #94a3b8;
    --color-text-info: #0284c7;
    --border-radius-lg: 8px;
    --border-radius-md: 4px;
}

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

body {
    background-color: #f1f5f9;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    padding-top: 3.5rem;
    display: flex;
    justify-content: center;
    min-height: 100vh;
}

nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 3rem;
    display: flex;
    align-items: center;
    border-bottom: 0.5px solid var(--color-border-tertiary);
    padding: 0 1rem;
    background: var(--color-background-primary);
    z-index: 1000;
    overflow-x: auto;
    white-space: nowrap;
    -webkit-overflow-scrolling: touch;
}

nav::-webkit-scrollbar { display: none; }
nav { -ms-overflow-style: none; scrollbar-width: none; }

.nbrand {
    font-weight: 600;
    font-size: 0.95rem;
    margin-right: auto;
    color: var(--color-text-primary);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    cursor: pointer;
    padding-right: 1rem;
    flex-shrink: 0;
    border: none;
    background: none;
}

.nbrand i {
    color: var(--color-text-info);
    margin-right: 0.35rem;
    font-size: 1.1rem;
}

.ntab {
    padding: 0 0.6rem;
    height: 3rem;
    border: none;
    background: none;
    cursor: pointer;
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    font-weight: 500;
    border-bottom: 2px solid transparent;
    transition: all 0.2s ease;
    flex-shrink: 0;
}

.ntab:hover { color: var(--color-text-primary); }
.ntab.on { color: var(--color-text-info); border-bottom-color: var(--color-border-info); }

#site {
    background: var(--color-background-primary);
    border-radius: var(--border-radius-lg);
    border: 0.5px solid var(--color-border-tertiary);
    display: flex;
    flex-direction: column;
    width: 100%;
    max-width: 650px;
    overflow: hidden;
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.05);
    margin-bottom: 2rem;
}

#body { flex: 1; padding: 1.5rem; }
.pg { display: none; }
.pg.on { display: block; }

h1 { font-size: 1.5rem; font-weight: 500; line-height: 1.25; margin-bottom: 0.6rem; color: var(--color-text-primary); }
h1 em { font-style: normal; color: var(--color-text-info); }
h2 { font-size: 1.1rem; font-weight: 500; margin-bottom: 0.75rem; color: var(--color-text-primary); margin-top: 0.5rem; }
h3 { font-size: 0.9rem; font-weight: 500; margin-bottom: 0.25rem; color: var(--color-text-primary); }
p { font-size: 0.85rem; color: var(--color-text-secondary); line-height: 1.65; margin-bottom: 0.75rem; }

button {
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius-md);
    border: 1px solid var(--color-border-tertiary);
    background: var(--color-background-primary);
    color: var(--color-text-primary);
    font-size: 0.8rem;
    cursor: pointer;
    font-family: inherit;
    transition: all 0.2s ease;
}
button:hover { background: var(--color-background-secondary); }
.price-featured button, .row button:first-child, .pricing-table button {
    background: var(--color-text-primary);
    color: #ffffff;
    border-color: var(--color-text-primary);
}

.card { background: var(--color-background-secondary); border-radius: var(--border-radius-lg); padding: 0.85rem 1rem; border: 0.5px solid var(--color-border-tertiary); }
.grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0.6rem; margin-bottom: 1rem; }
.sep { height: 0.5px; background: var(--color-border-tertiary); margin: 1rem 0; }

.pricing-table { width: 100%; border-collapse: collapse; margin-top: 1rem; font-size: 0.85rem; }
.pricing-table th, .pricing-table td { padding: 0.75rem; text-align: left; border-bottom: 1px solid var(--color-border-tertiary); }
.pricing-table th { background-color: var(--color-background-secondary); color: var(--color-text-primary); font-weight: 500; }
.strike { text-decoration: line-through; color: var(--color-text-tertiary); font-size: 0.75rem; margin-right: 0.25rem; }

ul.fl { list-style: none; display: flex; flex-direction: column; gap: 0.3rem; }
ul.fl li { font-size: 0.8rem; color: var(--color-text-secondary); }
ul.fl li::before { content: "✓ "; color: var(--color-text-info); }
.badge { font-size: 0.7rem; background: var(--color-background-info); color: var(--color-text-info); padding: 0.15rem 0.5rem; border-radius: var(--border-radius-md); display: inline-block; margin-bottom: 0.4rem; }
.amt { font-size: 1.4rem; font-weight: 500; color: var(--color-text-primary); margin: 0.15rem 0 0.1rem; }
.amt span { font-size: 0.8rem; font-weight: 400; color: var(--color-text-secondary); }

.topic-item {
    margin-bottom: 1rem;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}
.topic-btn {
    display: inline-flex;
    align-items: center;
    color: var(--color-text-info);
    font-size: 0.85rem;
    font-weight: 600;
    text-decoration: none;
    margin-top: 0.25rem;
}
.topic-btn:hover { text-decoration: underline; }

.back-btn {
    display: inline-flex;
    align-items: center;
    color: var(--color-text-secondary);
    font-size: 0.8rem;
    text-decoration: none;
    margin-bottom: 1rem;
    font-weight: 500;
}
.back-btn:hover { color: var(--color-text-info); }