:root {
  --color-text: #1f2933;
  --color-muted: #647382;
  --color-border: #d3dce6;
  --color-bg: #f5f7fa;
  --color-panel: #ffffff;
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-success: #15803d;
  --color-success-bg: #dcfce7;
  --color-error: #b91c1c;
  --color-error-bg: #fee2e2;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

body {
  margin: 0;
  padding: 24px 16px 48px;
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.5;
  color: var(--color-text);
  background: var(--color-bg);
}

main, header { max-width: 900px; margin: 0 auto; }
h1 { font-size: 1.6rem; margin: 0 0 4px; }
h2 { font-size: 1.15rem; margin: 0 0 12px; }
p.subtitle { margin: 0 0 20px; color: var(--color-muted); }

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 0 0 24px;
  padding: 12px 0;
  border-bottom: 1px solid var(--color-border);
}
nav a { color: var(--color-primary); text-decoration: none; font-weight: 600; }
nav a:hover, nav a:focus { text-decoration: underline; }

ul.link-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
ul.link-list a {
  display: block;
  padding: 14px 16px;
  background: var(--color-panel);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 600;
}
ul.link-list a:hover, ul.link-list a:focus { border-color: var(--color-primary); }

section {
  margin-bottom: 24px;
  padding: 18px;
  background: var(--color-panel);
  border: 1px solid var(--color-border);
  border-radius: 8px;
}
form { display: flex; flex-direction: column; gap: 12px; }
form.inline { flex-direction: row; flex-wrap: wrap; align-items: flex-end; }
label { display: flex; flex-direction: column; gap: 4px; font-weight: 600; font-size: 0.92rem; }
input, select, textarea {
  font: inherit;
  color: inherit;
  padding: 9px 10px;
  border: 1px solid var(--color-border);
  border-radius: 6px;
  background: #fff;
  width: 100%;
}
textarea { min-height: 72px; resize: vertical; }
input:focus, select:focus, textarea:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 1px;
  border-color: var(--color-primary);
}
button {
  font: inherit;
  font-weight: 600;
  padding: 10px 18px;
  border: 1px solid var(--color-primary);
  border-radius: 6px;
  background: var(--color-primary);
  color: #fff;
  cursor: pointer;
}
button:hover, button:focus { background: var(--color-primary-dark); border-color: var(--color-primary-dark); }
button:disabled { cursor: wait; opacity: 0.65; }
button.secondary { background: #fff; color: var(--color-primary); }
button.secondary:hover, button.secondary:focus { background: #eff6ff; }
button.danger { background: var(--color-error); border-color: var(--color-error); }
button.danger:hover, button.danger:focus { background: #991b1b; border-color: #991b1b; }

table { width: 100%; border-collapse: collapse; margin-top: 12px; font-size: 0.94rem; }
th, td { border: 1px solid var(--color-border); padding: 8px 10px; text-align: left; vertical-align: top; }
thead th { background: #eef2f7; }
tbody tr:nth-child(even) { background: #fafbfc; }
/* Man hinh dien thoai: bang nhieu cot cuon ngang trong khung, khong day ca trang. */
@media (max-width: 720px) {
  table { display: block; overflow-x: auto; -webkit-overflow-scrolling: touch; }
}

.result {
  margin-top: 4px;
  padding: 12px 14px;
  border-radius: 6px;
  border: 1px solid var(--color-border);
  background: #f8fafc;
  white-space: pre-wrap;
  word-break: break-word;
}
.result:empty { display: none; }
.result.success { color: var(--color-success); background: var(--color-success-bg); border-color: var(--color-success); }
.result.error { color: var(--color-error); background: var(--color-error-bg); border-color: var(--color-error); }
.hidden { display: none; }
video {
  width: 100%;
  max-width: 360px;
  margin-top: 10px;
  border: 1px solid var(--color-border);
  border-radius: 6px;
  background: #000;
}
pre.json {
  margin: 12px 0 0;
  padding: 12px;
  overflow-x: auto;
  background: #0f172a;
  color: #e2e8f0;
  border-radius: 6px;
  font-size: 0.85rem;
}
.hint { color: var(--color-muted); font-size: 0.88rem; margin: 0; }

.employee-page, .activation-page { max-width: 620px; }
.phone-card { padding: 22px 18px; border-radius: 14px; }
.phone-card h2 { font-size: 1.3rem; line-height: 1.3; }
.phone-card p { margin-top: 0; }
.phone-card .hint { margin-top: 16px; }
.phone-status { font-size: 1.08rem; line-height: 1.5; margin-bottom: 20px; }
.phone-action { display: block; width: 100%; min-height: 58px; padding: 14px 18px; font-size: 1.1rem; border-radius: 10px; }
.phone-form { gap: 18px; margin-top: 18px; }
.phone-form label { gap: 7px; font-size: 1rem; }
.phone-form input, .phone-form select, .phone-form textarea { min-height: 50px; padding: 11px 12px; }
.phone-form textarea { min-height: 100px; }
.phone-card .result { margin-top: 16px; }

@media (max-width: 480px) {
  body { padding: 18px 12px 36px; }
  .phone-card { padding: 22px 16px; }
  .employee-page h1, .activation-page h1 { font-size: 1.75rem; }
}

/* Bao cao: o tom tat + bang cong. */
.summary-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 10px; margin-top: 8px; }
.summary-item { border: 1px solid var(--color-border); border-radius: 6px; padding: 10px 12px; background: #f8fafc; }
.summary-item strong { display: block; font-size: 1.3rem; }
.summary-item span { font-size: 0.88rem; color: #475569; }
.summary-item.warn { border-color: var(--color-error); background: var(--color-error-bg); }
.summary-item.warn strong { color: var(--color-error); }
tfoot th { background: #eef2f7; }
button.link { background: none; border: none; padding: 0; color: var(--color-primary); text-decoration: underline; font: inherit; cursor: pointer; }
details > summary { cursor: pointer; font-weight: 600; }
button.link:hover, button.link:focus { background: none; color: var(--color-primary); }