/* ===== Site hướng dẫn sử dụng — phẳng, sạch, dễ nhìn (Win10-ish) ===== */
* { box-sizing: border-box; }
:root {
    --accent: #0078d4; --accent-dark: #005a9e; --ink: #1b1d21; --muted: #5b626b;
    --line: #e3e6ea; --bg: #f4f6f8; --card: #ffffff; --code: #eef2f6; --tip: #e8f4ff; --warn: #fff5e6; --ok: #e9f7ef;
}
html, body { margin: 0; padding: 0; }
body { font-family: 'Segoe UI', Roboto, Arial, sans-serif; color: var(--ink); background: var(--bg); line-height: 1.65; font-size: 15px; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* Top bar */
.hd-top { position: sticky; top: 0; z-index: 20; display: flex; align-items: center; gap: 14px; height: 56px; padding: 0 22px;
    background: linear-gradient(90deg, var(--accent-dark), var(--accent)); color: #fff; box-shadow: 0 2px 10px rgba(0,0,0,.15); }
.hd-top .brand { font-weight: 700; font-size: 17px; display: flex; align-items: center; gap: 10px; }
.hd-top .brand i { font-size: 19px; }
.hd-top nav { margin-left: auto; display: flex; gap: 4px; flex-wrap: wrap; }
.hd-top nav a { color: #fff; padding: 7px 13px; border-radius: 4px; font-size: 13.5px; opacity: .92; }
.hd-top nav a:hover { background: rgba(255,255,255,.16); text-decoration: none; opacity: 1; }
.hd-top nav a.on { background: rgba(255,255,255,.22); opacity: 1; }

/* Layout */
.hd-wrap { max-width: 1180px; margin: 0 auto; display: flex; gap: 26px; padding: 26px 22px 60px; }
.hd-side { flex: 0 0 232px; position: sticky; top: 78px; align-self: flex-start; max-height: calc(100vh - 96px); overflow: auto; }
.hd-side h4 { font-size: 12px; text-transform: uppercase; letter-spacing: .5px; color: var(--muted); margin: 14px 8px 6px; }
.hd-side a { display: block; padding: 7px 12px; border-radius: 5px; color: var(--ink); font-size: 13.5px; border-left: 3px solid transparent; }
.hd-side a:hover { background: #eaeef2; text-decoration: none; }
.hd-side a.on { background: #e4eefb; border-left-color: var(--accent); color: var(--accent-dark); font-weight: 600; }
.hd-main { flex: 1 1 auto; min-width: 0; }

/* Hero / cards (trang chủ) */
.hd-hero { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 30px 32px; margin-bottom: 24px; }
.hd-hero h1 { margin: 0 0 8px; font-size: 28px; }
.hd-hero p { color: var(--muted); margin: 0; font-size: 16px; }
.hd-cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 16px; }
.hd-card { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 18px 20px; transition: box-shadow .15s, transform .15s; display: block; color: var(--ink); }
.hd-card:hover { box-shadow: 0 8px 24px rgba(0,0,0,.10); transform: translateY(-2px); text-decoration: none; }
.hd-card .ic { width: 44px; height: 44px; border-radius: 10px; display: flex; align-items: center; justify-content: center; font-size: 20px; color: #fff; background: var(--accent); margin-bottom: 10px; }
.hd-card h3 { margin: 0 0 5px; font-size: 16px; }
.hd-card p { margin: 0; color: var(--muted); font-size: 13.5px; }

/* Content */
.hd-main h1.page-title { font-size: 26px; margin: 0 0 6px; }
.hd-main .lead { color: var(--muted); font-size: 16px; margin: 0 0 22px; }
.hd-sec { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 22px 26px; margin-bottom: 22px; scroll-margin-top: 78px; }
.hd-sec h2 { margin: 0 0 4px; font-size: 20px; display: flex; align-items: center; gap: 10px; }
.hd-sec h2 .ic { width: 32px; height: 32px; border-radius: 8px; background: #eaf3fc; color: var(--accent-dark); display: inline-flex; align-items: center; justify-content: center; font-size: 15px; }
.hd-sec .goal { color: var(--muted); margin: 2px 0 14px; }
.hd-sec h3 { font-size: 15.5px; margin: 18px 0 8px; }

ol.steps { counter-reset: step; list-style: none; padding: 0; margin: 0; }
ol.steps > li { position: relative; padding: 4px 0 14px 42px; margin: 0; }
ol.steps > li::before { counter-increment: step; content: counter(step); position: absolute; left: 0; top: 2px;
    width: 28px; height: 28px; border-radius: 50%; background: var(--accent); color: #fff; font-weight: 700; font-size: 13px;
    display: flex; align-items: center; justify-content: center; }
ol.steps > li:not(:last-child)::after { content: ''; position: absolute; left: 13px; top: 32px; bottom: 0; width: 2px; background: var(--line); }
ol.steps b { color: var(--accent-dark); }

.tip, .warn, .ok { border-radius: 8px; padding: 11px 15px; margin: 14px 0; font-size: 14px; border-left: 4px solid; }
.tip { background: var(--tip); border-color: var(--accent); }
.warn { background: var(--warn); border-color: #e6a23c; }
.ok { background: var(--ok); border-color: #2faa5d; }
.tip b, .warn b, .ok b { color: var(--ink); }

code, .kbd { background: var(--code); padding: 2px 7px; border-radius: 4px; font-family: Consolas, monospace; font-size: 13px; }
.path { color: var(--accent-dark); font-weight: 600; }

table.tbl { width: 100%; border-collapse: collapse; margin: 14px 0; font-size: 14px; }
table.tbl th, table.tbl td { border: 1px solid var(--line); padding: 8px 11px; text-align: left; }
table.tbl th { background: #f0f4f8; }

/* Figure / ảnh màn hình */
figure.shot { margin: 16px 0; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; background: var(--card); }
figure.shot img { display: block; width: 100%; height: auto; }
figure.shot .ph { display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 8px;
    height: 230px; background: repeating-linear-gradient(45deg, #f3f6f9, #f3f6f9 12px, #eef2f6 12px, #eef2f6 24px); color: var(--muted); }
figure.shot .ph i { font-size: 30px; opacity: .5; }
figure.shot figcaption { padding: 9px 14px; font-size: 13px; color: var(--muted); border-top: 1px solid var(--line); background: #fafbfc; }
figure.shot figcaption b { color: var(--ink); }

.menu-path { display: inline-flex; align-items: center; gap: 6px; background: #eef2f6; padding: 3px 10px; border-radius: 14px; font-size: 13px; font-weight: 600; color: var(--accent-dark); }
.menu-path i { font-size: 10px; opacity: .6; }

.hd-foot { text-align: center; color: var(--muted); font-size: 13px; padding: 30px 0; }
@media (max-width: 820px) { .hd-side { display: none; } .hd-wrap { padding: 18px 14px 40px; } }