/* 课堂管控 —— 无构建依赖的静态样式。
   目标是"清楚、可聚焦、可读"，不做营销式视觉。 */

:root {
  --bg: #f6f7f9;
  --surface: #ffffff;
  --ink: #1b1f24;
  --ink-soft: #5a6472;
  --line: #d6dbe2;
  --accent: #1f5fbf;
  --accent-ink: #ffffff;
  --ok: #1a6b3c;
  --ok-bg: #e6f4ea;
  --bad: #a3231c;
  --bad-bg: #fdecea;
  --warn: #7a4a00;
  --warn-bg: #fff4e0;
  --unknown: #4a3b7a;
  --unknown-bg: #efeafd;
  --pending: #31465e;
  --pending-bg: #e9eef5;
  --radius: 10px;
  --focus: 0 0 0 3px rgba(31, 95, 191, 0.45);
}

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

body {
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.55 -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei",
        "Noto Sans CJK SC", sans-serif;
  padding-bottom: 2rem;
}

[hidden] { display: none !important; }

h1, h2, h3 { line-height: 1.3; margin: 0 0 0.6rem; }
h1 { font-size: 1.25rem; }
h2 { font-size: 1.05rem; }
h3 { font-size: 0.95rem; color: var(--ink-soft); }

p { margin: 0.4rem 0; }

code {
  font-family: ui-monospace, "Cascadia Mono", Consolas, monospace;
  background: #eef1f5;
  padding: 0.05em 0.35em;
  border-radius: 4px;
  font-size: 0.9em;
}

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--surface);
  padding: 0.5rem 1rem;
  z-index: 10;
}
.skip:focus { left: 0.5rem; top: 0.5rem; }

/* ---------- 顶栏 ---------- */

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 1.25rem;
  background: var(--surface);
  border-bottom: 1px solid var(--line);
}

.who {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  color: var(--ink-soft);
  font-size: 0.92rem;
}

main {
  max-width: 1080px;
  margin: 0 auto;
  padding: 1.25rem;
}

/* ---------- 卡片与提示 ---------- */

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.1rem 1.25rem 1.25rem;
  margin-bottom: 1rem;
}

.card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}

.notice {
  background: var(--warn-bg);
  border: 1px solid #e8cf9e;
  color: var(--warn);
  border-radius: var(--radius);
  padding: 0.75rem 0.9rem;
  margin-bottom: 1rem;
  font-size: 0.94rem;
}

.foot {
  max-width: 1080px;
  margin: 0 auto;
  padding: 1rem 1.25rem 0;
  border-top: 1px solid var(--line);
}

.muted { color: var(--ink-soft); }
.small { font-size: 0.86rem; }

/* ---------- 表单 ---------- */

.field {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  margin-bottom: 0.85rem;
}

label { font-size: 0.92rem; color: var(--ink-soft); }

input[type="text"],
input[type="password"],
select {
  font: inherit;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0.55rem 0.65rem;
  min-height: 44px;
  width: 100%;
  max-width: 26rem;
}

select { max-width: 12rem; }

input:focus-visible,
select:focus-visible,
button:focus-visible,
a:focus-visible {
  outline: none;
  box-shadow: var(--focus);
  border-color: var(--accent);
}

/* ---------- 按钮 ---------- */

button {
  font: inherit;
  cursor: pointer;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--ink);
  padding: 0.6rem 1rem;
  min-height: 44px;
}

button:hover:not(:disabled) { border-color: #b6bfcb; background: #fafbfc; }

button:disabled {
  cursor: not-allowed;
  opacity: 0.5;
  background: #f1f3f6;
}

button.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-ink);
  font-weight: 600;
}

button.primary:hover:not(:disabled) { background: #1a51a4; border-color: #1a51a4; }

button.secondary { background: #f3f5f8; }
button.small { min-height: 36px; padding: 0.35rem 0.7rem; font-size: 0.9rem; }

button.linkish {
  border: 0;
  background: none;
  color: var(--accent);
  padding: 0.3rem 0.4rem;
  min-height: 36px;
  text-decoration: underline;
}

/* ---------- 两栏布局 ---------- */

.layout {
  display: grid;
  grid-template-columns: minmax(240px, 320px) minmax(0, 1fr);
  gap: 1rem;
  align-items: start;
}

@media (max-width: 760px) {
  .layout { grid-template-columns: 1fr; }
  main { padding: 0.9rem; }
  input[type="text"], input[type="password"], select { max-width: none; }
}

/* ---------- 设备列表 ---------- */

.device-list {
  list-style: none;
  margin: 0.5rem 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.device-list button {
  width: 100%;
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  padding: 0.6rem 0.7rem;
}

.device-list button[aria-pressed="true"] {
  border-color: var(--accent);
  box-shadow: inset 3px 0 0 var(--accent);
  background: #f5f8ff;
}

.device-name { font-weight: 600; }
.device-meta { font-size: 0.85rem; color: var(--ink-soft); }

.dot {
  display: inline-block;
  width: 0.6em;
  height: 0.6em;
  border-radius: 50%;
  margin-right: 0.35em;
  background: #9aa4b1;
  vertical-align: 0.05em;
}
.dot.online { background: var(--ok); }
.dot.offline { background: #9aa4b1; }

/* ---------- 详情 ---------- */

.facts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 0.5rem 1.25rem;
  margin: 0 0 1rem;
}

.facts > div {
  display: flex;
  justify-content: space-between;
  gap: 0.75rem;
  border-bottom: 1px dashed var(--line);
  padding-bottom: 0.35rem;
}

.facts dt { color: var(--ink-soft); font-size: 0.9rem; flex-shrink: 0; white-space: nowrap; }
.facts dd { margin: 0; text-align: right; min-width: 0; overflow-wrap: anywhere; }

.controls {
  border-top: 1px solid var(--line);
  padding-top: 1rem;
  margin-top: 0.5rem;
}

.lease-field { margin-bottom: 0.75rem; }

.buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-bottom: 0.5rem;
}

.buttons button { flex: 1 1 10rem; }

.command {
  border-top: 1px solid var(--line);
  margin-top: 1rem;
  padding-top: 0.9rem;
}

/* ---------- 状态消息 ---------- */

.msg {
  padding: 0.6rem 0.75rem;
  border-radius: 8px;
  border: 1px solid transparent;
  margin: 0.4rem 0;
}

.msg.muted { background: var(--pending-bg); color: var(--pending); }

.msg.ok { background: var(--ok-bg); color: var(--ok); border-color: #b7ddc4; }
.msg.bad { background: var(--bad-bg); color: var(--bad); border-color: #f0c2be; }
.msg.warn { background: var(--warn-bg); color: var(--warn); border-color: #e8cf9e; }
.msg.unknown { background: var(--unknown-bg); color: var(--unknown); border-color: #cec2f0; }
.msg.pending { background: var(--pending-bg); color: var(--pending); border-color: #cbd6e4; }