:root {
    --bg: #f6f7f9;
    --surface: #ffffff;
    --text: #1f2937;
    --muted: #6b7280;
    --brand: #0f766e;
    --border: #e5e7eb;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", sans-serif;
    line-height: 1.9;
    color: var(--text);
    background: var(--bg);
}

.topbar {
    position: sticky;
    top: 0;
    z-index: 10;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0 24px;
    border-bottom: 1px solid var(--border);
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(8px);
}

.topbar-inner {
    width: min(1100px, 100%);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.brand {
    font-weight: 700;
    font-size: 1.1rem;
    letter-spacing: 0.02em;
}

.nav {
    display: flex;
    gap: 16px;
    color: var(--muted);
    font-size: 0.95rem;
}

.nav span:hover {
    color: var(--brand);
    cursor: default;
}

main {
    width: min(920px, 100%);
    margin: 36px auto 48px;
    padding: 0 20px;
}

article {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 0px;
    padding: 36px 42px;
    box-shadow: 0 16px 30px rgba(15, 23, 42, 0.05);
}

h1 {
    margin: 0 0 8px;
    color: #111111;
    font-size: clamp(2rem, 4vw, 2.7rem);
    line-height: 1.2;
    letter-spacing: 0.01em;
}

.meta {
    margin: 0 0 26px;
    color: var(--muted);
    font-size: 0.95rem;
}

.content p {
    margin: 0 0 1.1em;
    color: #111111;
}

.content {
    line-height: 1.73;
    letter-spacing: 0.018em;
    font-size: 0.95rem;
}

.content h1, .content h2, .content h3 {
    color: #111111;
    line-height: 1.3;
    font-weight: 700;
}

.content h1 {
    margin-top: 1.3em;
    margin-bottom: 0.55em;
    font-size: 2.05rem;
}

.content h2 {
    margin-top: 1.1em;
    margin-bottom: 0.6em;
    font-size: 1.55rem;
}

.content h3 {
    margin-top: 1.05em;
    margin-bottom: 0.6em;
    font-size: 1.25rem;
}

.content a {
    color: var(--brand);
    text-decoration-thickness: 2px;
    text-underline-offset: 2px;
}

.content blockquote {
    margin: 1.4em 0;
    padding: 0.8em 1em;
    border-left: 4px solid #bcd7c6;
    background: #f8fafc;
    color: #374151;
}

.content ul, .content ol {
    padding-left: 1.45em;
}

.content code {
    padding: 0.15em 0.4em;
    border-radius: 6px;
    background: #f3f4f6;
    font-size: 0.92em;
}

footer {
    width: min(920px, 100%);
    margin: 0 auto 28px;
    padding: 0 20px;
    color: var(--muted);
    font-size: 0.9rem;
}

@media (max-width: 720px) {
    .nav {
        display: none;
    }

    article {
        padding: 28px 20px;
        border-radius: 12px;
    }
}