/* =============================================================================
   半導体技能検定 CBT — Tech Style (高级科技风)
   深蓝/电光蓝(cyan) · 渐变与微光 · 玻璃拟态 · 移动优先
   断点: ≥600px / ≥960px
   仅覆盖各视图真实类名(login/home/exam/result/history/admin + nav + 共享)
   ============================================================================= */

/* ---------- 设计令牌 ---------- */
:root {
  /* 背景层(深空蓝) */
  --bg-0: #060b18;
  --bg-1: #0a1426;
  --bg-2: #0f1d36;

  /* 玻璃拟态 */
  --glass: rgba(20, 36, 64, 0.55);
  --glass-2: rgba(26, 46, 80, 0.45);
  --glass-border: rgba(120, 190, 255, 0.16);
  --glass-border-strong: rgba(120, 190, 255, 0.32);

  /* 文字 */
  --text: #e8f1ff;
  --text-soft: #aabfdc;
  --text-dim: #6f86ab;

  /* 电光蓝 / 青 */
  --cyan: #2ad4ff;
  --cyan-soft: #6fe3ff;
  --blue: #3b82f6;
  --blue-deep: #1d4ed8;
  --accent-grad: linear-gradient(135deg, #2ad4ff 0%, #3b82f6 55%, #6d5dfc 100%);
  --accent-grad-soft: linear-gradient(135deg, rgba(42,212,255,.18), rgba(109,93,252,.18));

  /* 语义色 */
  --ok: #2ee6a6;
  --ok-deep: #0e9c6f;
  --warn: #ffcf5c;
  --danger: #ff6b6b;
  --danger-deep: #d6303a;

  /* 微光 / 阴影 */
  --glow-cyan: 0 0 0 1px rgba(42,212,255,.35), 0 8px 30px rgba(42,212,255,.18);
  --shadow-sm: 0 2px 8px rgba(2, 8, 20, 0.45);
  --shadow-md: 0 10px 30px rgba(2, 8, 20, 0.55);
  --shadow-lg: 0 20px 50px rgba(2, 8, 20, 0.65);

  /* 半径 */
  --r-sm: 10px;
  --r-md: 14px;
  --r-lg: 20px;
  --r-pill: 999px;

  /* 等宽数字字体(计时/分数) */
  --mono: ui-monospace, "SF Mono", "Cascadia Mono", "JetBrains Mono",
          "Roboto Mono", Menlo, Consolas, monospace;

  --tap: 44px; /* 最小触摸目标 */
}

/* ---------- 基础重置 ---------- */
*, *::before, *::after { box-sizing: border-box; }

html, body {
  overflow-x: hidden;      /* 关键: 禁止横向溢出 */
  margin: 0;
  padding: 0;
}

html { -webkit-text-size-adjust: 100%; }

body {
  min-height: 100vh;
  font-family: system-ui, -apple-system, "Segoe UI", "Hiragino Sans",
               "Noto Sans JP", "Yu Gothic UI", Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background:
    radial-gradient(1100px 700px at 12% -8%, rgba(42,212,255,.14), transparent 60%),
    radial-gradient(900px 600px at 105% 0%, rgba(109,93,252,.16), transparent 55%),
    radial-gradient(800px 800px at 50% 120%, rgba(59,130,246,.10), transparent 60%),
    linear-gradient(180deg, var(--bg-1) 0%, var(--bg-0) 100%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* 细网格科技底纹 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(120,190,255,.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(120,190,255,.045) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(ellipse at 50% 30%, #000 30%, transparent 80%);
  -webkit-mask-image: radial-gradient(ellipse at 50% 30%, #000 30%, transparent 80%);
}

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 16px 14px calc(40px + env(safe-area-inset-bottom));
}

h1, h2, h3, h4 { margin: 0 0 .5em; line-height: 1.25; font-weight: 700; letter-spacing: .01em; }

a { color: var(--cyan-soft); text-decoration: none; }
a:hover { text-decoration: underline; }

code {
  font-family: var(--mono);
  font-size: .9em;
  padding: .12em .4em;
  border-radius: 6px;
  background: rgba(42,212,255,.12);
  border: 1px solid var(--glass-border);
  color: var(--cyan-soft);
}

::selection { background: rgba(42,212,255,.35); color: #fff; }

/* 焦点可见性(无障碍) */
:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
  border-radius: 4px;
}

/* =============================================================================
   导航栏 #nav
   ============================================================================= */
#nav {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  padding: 10px 14px;
  padding-top: max(10px, env(safe-area-inset-top));
  background: linear-gradient(180deg, rgba(10,20,38,.92), rgba(10,20,38,.72));
  backdrop-filter: blur(14px) saturate(160%);
  -webkit-backdrop-filter: blur(14px) saturate(160%);
  border-bottom: 1px solid var(--glass-border);
  box-shadow: 0 6px 24px rgba(2,8,20,.45);
}
#nav[hidden] { display: none; }

.nav-brand {
  font-weight: 800;
  font-size: 1.02rem;
  letter-spacing: .02em;
  background: var(--accent-grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  white-space: nowrap;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.nav-link {
  min-height: var(--tap);
  display: inline-flex;
  align-items: center;
  padding: 8px 14px;
  border: 1px solid transparent;
  border-radius: var(--r-pill);
  background: rgba(255,255,255,.04);
  color: var(--text-soft);
  font-size: .92rem;
  font-weight: 600;
  cursor: pointer;
  transition: color .18s, background .18s, border-color .18s, box-shadow .18s;
}
.nav-link:hover {
  color: var(--text);
  background: var(--accent-grad-soft);
  border-color: var(--glass-border-strong);
  box-shadow: 0 0 18px rgba(42,212,255,.18);
}
.nav-link:active { transform: translateY(1px); }

.nav-user {
  min-height: var(--tap);
  display: inline-flex;
  align-items: center;
  padding: 0 6px 0 10px;
  color: var(--text-dim);
  font-size: .86rem;
  white-space: nowrap;
}

.nav-logout { color: var(--cyan-soft); }
.nav-logout:hover {
  color: #fff;
  background: rgba(255,107,107,.14);
  border-color: rgba(255,107,107,.4);
  box-shadow: 0 0 18px rgba(255,107,107,.2);
}

/* =============================================================================
   共享: 卡片 / 玻璃拟态
   ============================================================================= */
.card {
  position: relative;
  background: var(--glass);
  backdrop-filter: blur(16px) saturate(150%);
  -webkit-backdrop-filter: blur(16px) saturate(150%);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-lg);
  padding: 18px;
  margin: 0 0 16px;
  box-shadow: var(--shadow-md);
}
/* 顶部高光描边 */
.card::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(160deg, rgba(120,190,255,.35), transparent 40%);
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
}

/* =============================================================================
   共享: 按钮
   ============================================================================= */
.btn {
  -webkit-appearance: none;
  appearance: none;
  min-height: var(--tap);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 18px;
  border: 1px solid var(--glass-border-strong);
  border-radius: var(--r-md);
  background: rgba(255,255,255,.05);
  color: var(--text);
  font-size: .95rem;
  font-weight: 700;
  letter-spacing: .01em;
  line-height: 1.1;
  cursor: pointer;
  transition: transform .12s, box-shadow .18s, background .18s, border-color .18s, opacity .18s;
}
.btn:hover { border-color: var(--glass-border-strong); box-shadow: 0 6px 18px rgba(2,8,20,.4); }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .55; cursor: not-allowed; transform: none; box-shadow: none; }

.btn-block { display: flex; width: 100%; }

.btn-primary {
  border: none;
  background: var(--accent-grad);
  color: #04101f;
  text-shadow: 0 1px 0 rgba(255,255,255,.25);
  box-shadow: 0 8px 24px rgba(42,212,255,.28), inset 0 1px 0 rgba(255,255,255,.35);
}
.btn-primary:hover {
  box-shadow: 0 10px 30px rgba(42,212,255,.42), inset 0 1px 0 rgba(255,255,255,.4);
  filter: brightness(1.06);
}

.btn-secondary {
  background: var(--glass-2);
  color: var(--text);
  border: 1px solid var(--glass-border-strong);
}
.btn-secondary:hover { background: var(--accent-grad-soft); }

.btn-danger {
  border: none;
  background: linear-gradient(135deg, #ff6b6b, #d6303a);
  color: #fff;
  box-shadow: 0 6px 18px rgba(214,48,58,.32);
}
.btn-danger:hover { filter: brightness(1.07); }

.btn-sm {
  min-height: 36px;
  padding: 6px 12px;
  font-size: .82rem;
  border-radius: var(--r-sm);
}

.btn-link {
  min-height: var(--tap);
  background: none;
  border: none;
  padding: 4px 8px;
  color: var(--cyan-soft);
  font-weight: 700;
  font-size: .88rem;
  cursor: pointer;
}
.btn-link:hover { color: #fff; text-decoration: underline; }

/* =============================================================================
   共享: 表单字段
   ============================================================================= */
.field { display: block; margin: 0 0 14px; }

.field-label {
  display: block;
  margin: 0 0 6px;
  font-size: .82rem;
  font-weight: 700;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.input,
.field-input,
.field-select,
.admin-form input,
.admin-form select,
.admin-form textarea {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  min-height: var(--tap);
  padding: 11px 14px;
  font-size: 16px; /* 防 iOS 缩放 */
  font-family: inherit;
  color: var(--text);
  background: rgba(6,14,28,.6);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-md);
  transition: border-color .18s, box-shadow .18s, background .18s;
}
.input::placeholder,
.field-input::placeholder,
.admin-form textarea::placeholder { color: var(--text-dim); }

.input:focus,
.field-input:focus,
.field-select:focus,
.admin-form input:focus,
.admin-form select:focus,
.admin-form textarea:focus {
  outline: none;
  border-color: var(--cyan);
  background: rgba(6,14,28,.85);
  box-shadow: 0 0 0 3px rgba(42,212,255,.2), 0 0 22px rgba(42,212,255,.14);
}

/* 下拉箭头 */
.field-select,
.admin-form select {
  background-image:
    linear-gradient(45deg, transparent 50%, var(--cyan-soft) 50%),
    linear-gradient(135deg, var(--cyan-soft) 50%, transparent 50%);
  background-position:
    calc(100% - 20px) calc(50% - 2px),
    calc(100% - 15px) calc(50% - 2px);
  background-size: 5px 5px, 5px 5px;
  background-repeat: no-repeat;
  padding-right: 40px;
}
.field-select option,
.admin-form select option { background: var(--bg-2); color: var(--text); }

.field-hint { margin: 6px 0 0; font-size: .82rem; color: var(--text-dim); }

/* 共享提示色 */
.muted { color: var(--text-dim); }
.error {
  color: var(--danger);
  background: rgba(255,107,107,.1);
  border: 1px solid rgba(255,107,107,.3);
  border-radius: var(--r-sm);
  padding: 8px 12px;
}
.error-box { text-align: center; }
.error-box .btn { margin-top: 12px; }
.view-title {
  font-size: 1.4rem;
  background: var(--accent-grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* =============================================================================
   LOGIN 视图
   ============================================================================= */
.login-wrap {
  min-height: calc(100vh - 90px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px 4px;
}
.login-card {
  width: 100%;
  max-width: 400px;
  margin: 0;
  padding: 28px 22px;
  box-shadow: var(--shadow-lg);
}
.login-card::after {
  content: "";
  position: absolute;
  top: -1px; left: 18px; right: 18px;
  height: 2px;
  border-radius: 2px;
  background: var(--accent-grad);
  box-shadow: 0 0 18px rgba(42,212,255,.6);
}
.login-title {
  margin: 4px 0 2px;
  font-size: 1.5rem;
  text-align: center;
  background: var(--accent-grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.login-sub {
  margin: 0 0 22px;
  text-align: center;
  color: var(--text-dim);
  font-size: .9rem;
  letter-spacing: .12em;
}
.login-error {
  margin: 4px 0 14px;
  padding: 10px 12px;
  border-radius: var(--r-sm);
  background: rgba(255,107,107,.12);
  border: 1px solid rgba(255,107,107,.34);
  color: #ffd2d2;
  font-size: .88rem;
}
.login-card .btn-block { margin-top: 6px; }
.login-hint {
  margin: 18px 0 0;
  padding-top: 16px;
  border-top: 1px solid var(--glass-border);
  text-align: center;
  font-size: .82rem;
  line-height: 1.9;
  color: var(--text-dim);
}

/* =============================================================================
   HOME 视图
   ============================================================================= */
.home-view { animation: fade-up .35s ease both; }
.home-title {
  font-size: 1.55rem;
  background: var(--accent-grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.home-hello { margin: 0 0 18px; color: var(--text-soft); }
.home-loading, .home-empty { color: var(--text-dim); padding: 8px 0; }
.home-error {
  color: var(--danger);
  background: rgba(255,107,107,.1);
  border: 1px solid rgba(255,107,107,.3);
  border-radius: var(--r-md);
  padding: 12px 14px;
}

/* 章节选择 */
.chap-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 10px;
}
.chap-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
  max-height: 320px;
  overflow-y: auto;
  margin: 0 -4px;
  padding: 2px 4px;
}
.chap-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  min-height: var(--tap);
  padding: 9px 12px;
  border-radius: var(--r-md);
  background: rgba(255,255,255,.03);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background .15s, border-color .15s;
}
.chap-item:hover { background: var(--accent-grad-soft); border-color: var(--glass-border); }
.chap-checkbox {
  flex: 0 0 auto;
  width: 20px;
  height: 20px;
  margin-top: 2px;
  accent-color: var(--cyan);
  cursor: pointer;
}
.chap-text { color: var(--text-soft); line-height: 1.5; }
.chap-item:hover .chap-text { color: var(--text); }

.home-view > .btn-primary.btn-block { margin-top: 4px; }

/* =============================================================================
   EXAM 视图
   ============================================================================= */
.exam-loading { color: var(--text-dim); padding: 24px 0; text-align: center; }
.exam-view { animation: fade-up .3s ease both; }

/* 顶部状态条: 进度 + 倒计时(粘顶) */
.exam-topbar {
  position: sticky;
  top: 58px;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin: 0 0 14px;
  padding: 10px 14px;
  border-radius: var(--r-md);
  background: var(--glass);
  backdrop-filter: blur(14px) saturate(150%);
  -webkit-backdrop-filter: blur(14px) saturate(150%);
  border: 1px solid var(--glass-border);
  box-shadow: var(--shadow-sm);
}
.exam-progress {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  color: var(--text-soft);
  letter-spacing: .02em;
}
.exam-timer {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-weight: 800;
  font-size: 1.12rem;
  letter-spacing: .04em;
  color: var(--cyan-soft);
  padding: 4px 12px;
  border-radius: var(--r-pill);
  background: rgba(42,212,255,.1);
  border: 1px solid rgba(42,212,255,.28);
  text-shadow: 0 0 14px rgba(42,212,255,.5);
}
.exam-timer.warn {
  color: #fff;
  background: rgba(255,107,107,.18);
  border-color: rgba(255,107,107,.5);
  text-shadow: 0 0 14px rgba(255,107,107,.6);
  animation: pulse-warn 1s ease-in-out infinite;
}
@keyframes pulse-warn {
  50% { box-shadow: 0 0 0 4px rgba(255,107,107,.18); }
}

/* 题号导航 */
.exam-nav-wrap {
  margin: 0 0 14px;
  border-radius: var(--r-md);
  background: var(--glass-2);
  border: 1px solid var(--glass-border);
  overflow: hidden;
}
.exam-nav-toggle {
  width: 100%;
  min-height: var(--tap);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  background: none;
  border: none;
  color: var(--text-soft);
  font-weight: 700;
  font-size: .9rem;
  cursor: pointer;
}
.exam-nav-toggle-caret { color: var(--cyan-soft); transition: transform .2s; }
.exam-nav-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(44px, 1fr));
  gap: 8px;
  padding: 4px 12px 14px;
}
.exam-nav-wrap.collapsed .exam-nav-grid { display: none; }

.exam-nav-btn {
  min-height: var(--tap);
  min-width: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: .9rem;
  color: var(--text-soft);
  background: rgba(6,14,28,.5);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-sm);
  cursor: pointer;
  transition: transform .12s, border-color .15s, box-shadow .15s, background .15s, color .15s;
}
.exam-nav-btn:active { transform: scale(.94); }
.exam-nav-btn.unanswered { color: var(--text-dim); }
.exam-nav-btn.answered {
  color: var(--cyan-soft);
  background: rgba(42,212,255,.12);
  border-color: rgba(42,212,255,.34);
}
.exam-nav-btn.flagged {
  border-color: var(--warn);
  box-shadow: inset 0 0 0 1px rgba(255,207,92,.5);
  color: var(--warn);
}
.exam-nav-btn.current {
  color: #04101f;
  background: var(--accent-grad);
  border-color: transparent;
  box-shadow: 0 0 16px rgba(42,212,255,.5);
}

/* 题卡 */
.exam-card {
  background: var(--glass);
  backdrop-filter: blur(16px) saturate(150%);
  -webkit-backdrop-filter: blur(16px) saturate(150%);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-lg);
  padding: 18px;
  margin: 0 0 14px;
  box-shadow: var(--shadow-md);
}
.exam-chapter {
  display: inline-block;
  margin: 0 0 12px;
  padding: 4px 12px;
  font-size: .76rem;
  font-weight: 700;
  letter-spacing: .05em;
  color: var(--cyan-soft);
  background: rgba(42,212,255,.1);
  border: 1px solid rgba(42,212,255,.26);
  border-radius: var(--r-pill);
}

/* 关键: 题干折行不截断 */
.exam-stem {
  margin: 0 0 18px;
  font-family: inherit;          /* 覆盖 <pre> 默认等宽 */
  font-size: 1.06rem;
  font-weight: 600;
  line-height: 1.7;
  color: var(--text);
  white-space: pre-wrap;         /* 保留换行并自动折行 */
  overflow-wrap: anywhere;       /* 长串(URL/型番)强制折断, 不溢出 */
  word-break: normal;
}

.exam-options { display: flex; flex-direction: column; gap: 10px; }
.exam-option {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  width: 100%;
  min-height: var(--tap);
  padding: 13px 15px;
  text-align: left;
  color: var(--text-soft);
  background: rgba(6,14,28,.4);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-md);
  cursor: pointer;
  transition: border-color .15s, background .15s, box-shadow .15s, transform .1s;
}
.exam-option:hover { border-color: var(--glass-border-strong); background: rgba(42,212,255,.06); }
.exam-option:active { transform: translateY(1px); }
.exam-option.selected {
  color: var(--text);
  background: var(--accent-grad-soft);
  border-color: var(--cyan);
  box-shadow: var(--glow-cyan);
}
.exam-option-label {
  flex: 0 0 auto;
  min-width: 1.5em;
  font-family: var(--mono);
  font-weight: 800;
  color: var(--cyan-soft);
}
.exam-option.selected .exam-option-label { color: var(--cyan); }
.exam-option-text {
  flex: 1 1 auto;
  line-height: 1.55;
  overflow-wrap: anywhere;       /* 选项也防溢出 */
}

/* 操作区 */
.exam-actions {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin: 0 0 14px;
}
.btn-flag {
  align-self: flex-start;
  min-height: var(--tap);
  padding: 9px 16px;
  background: var(--glass-2);
  border: 1px solid var(--glass-border-strong);
  border-radius: var(--r-pill);
  color: var(--text-soft);
  font-weight: 700;
  cursor: pointer;
  transition: color .15s, background .15s, border-color .15s, box-shadow .15s;
}
.btn-flag:hover { color: var(--text); }
.btn-flag.active {
  color: #1a1300;
  background: linear-gradient(135deg, #ffe08a, #ffcf5c);
  border-color: transparent;
  box-shadow: 0 0 18px rgba(255,207,92,.4);
}
.exam-prevnext { display: flex; gap: 10px; }
.exam-prevnext .btn { flex: 1 1 0; }

.exam-submitbar {
  position: sticky;
  bottom: 0;
  z-index: 15;
  margin: 4px -14px calc(-40px - env(safe-area-inset-bottom));
  padding: 12px 14px calc(14px + env(safe-area-inset-bottom));
  background: linear-gradient(180deg, transparent, rgba(6,11,24,.92) 30%);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.exam-error {
  background: var(--glass);
  border: 1px solid rgba(255,107,107,.3);
  border-radius: var(--r-lg);
  padding: 22px 18px;
  text-align: center;
  box-shadow: var(--shadow-md);
}
.exam-error p { color: #ffd2d2; margin: 0 0 16px; }

/* =============================================================================
   RESULT 视图
   注: result.js 对多数元素设置了内联样式(浅色主题), 内联会覆盖此处。
   此处为类名兜底, 保证未被内联覆盖的层级仍贴合科技风。
   ============================================================================= */
.res-view { animation: fade-up .35s ease both; }
.res-banner { border-radius: var(--r-md); }
.res-card { border-radius: var(--r-md); }
.res-score { text-align: center; }
.res-stats { display: flex; gap: 10px; }
.res-stat { border-radius: var(--r-md); }
.res-home {
  min-height: var(--tap);
  cursor: pointer;
}

/* =============================================================================
   HISTORY 视图
   ============================================================================= */
.history-view { animation: fade-up .35s ease both; }
.history-header { margin: 0 0 18px; }
.history-title {
  font-size: 1.5rem;
  background: var(--accent-grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.history-sub { margin: 0; color: var(--text-dim); font-size: .9rem; }

.history-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 12px; }
.history-item { margin: 0; }

.history-card {
  position: relative;
  width: 100%;
  min-height: var(--tap);
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 16px;
  text-align: left;
  background: var(--glass);
  backdrop-filter: blur(14px) saturate(150%);
  -webkit-backdrop-filter: blur(14px) saturate(150%);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-md);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  transition: transform .14s, border-color .16s, box-shadow .16s;
}
.history-card:hover {
  transform: translateY(-2px);
  border-color: var(--glass-border-strong);
  box-shadow: var(--shadow-md), 0 0 24px rgba(42,212,255,.12);
}
.history-card:active { transform: translateY(0); }
.history-card.loading { opacity: .6; cursor: progress; }

.history-card-top { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.history-date { font-family: var(--mono); font-variant-numeric: tabular-nums; font-size: .82rem; color: var(--text-dim); }

.history-badge {
  font-size: .74rem;
  font-weight: 800;
  letter-spacing: .04em;
  padding: 3px 11px;
  border-radius: var(--r-pill);
  white-space: nowrap;
}
.history-badge.pass {
  color: #04140d;
  background: linear-gradient(135deg, #4dffc0, var(--ok));
  box-shadow: 0 0 14px rgba(46,230,166,.35);
}
.history-badge.fail {
  color: #fff;
  background: linear-gradient(135deg, #ff8a8a, var(--danger-deep));
  box-shadow: 0 0 14px rgba(255,107,107,.3);
}

.history-profile { font-weight: 700; color: var(--text); font-size: 1.02rem; }

.history-card-bottom { display: flex; align-items: baseline; gap: 12px; }
.history-score {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--cyan-soft);
  text-shadow: 0 0 16px rgba(42,212,255,.3);
}
.history-meta { color: var(--text-dim); font-size: .85rem; }

.history-empty {
  text-align: center;
  padding: 40px 18px;
  background: var(--glass-2);
  border: 1px dashed var(--glass-border-strong);
  border-radius: var(--r-lg);
}
.history-empty-icon { font-size: 2.6rem; margin-bottom: 8px; filter: drop-shadow(0 0 14px rgba(42,212,255,.3)); }
.history-empty-title { margin: 0 0 6px; font-weight: 700; color: var(--text); }
.history-empty-text { margin: 0 0 18px; color: var(--text-dim); font-size: .9rem; }
.history-empty-cta { display: inline-flex; }

.history-error {
  text-align: center;
  padding: 20px 16px;
  background: rgba(255,107,107,.08);
  border: 1px solid rgba(255,107,107,.3);
  border-radius: var(--r-lg);
}
.history-error-text { margin: 0 0 14px; color: #ffd2d2; }
.history-retry { display: inline-flex; }

.history-info, .history-loading {
  text-align: center;
  padding: 22px 0;
  color: var(--text-dim);
}
.history-item-error {
  margin-top: 8px;
  padding: 8px 12px;
  font-size: .84rem;
  color: #ffd2d2;
  background: rgba(255,107,107,.1);
  border: 1px solid rgba(255,107,107,.28);
  border-radius: var(--r-sm);
}

/* =============================================================================
   ADMIN 视图
   ============================================================================= */
.admin-view { animation: fade-up .35s ease both; }
.admin-section { padding: 18px; }
.section-title {
  font-size: 1.12rem;
  margin: 0 0 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--glass-border);
  color: var(--text);
}
.section-title::before {
  content: "";
  display: inline-block;
  width: 8px; height: 8px;
  margin-right: 10px;
  border-radius: 2px;
  background: var(--accent-grad);
  box-shadow: 0 0 10px rgba(42,212,255,.6);
  vertical-align: middle;
}
.sub-title { font-size: .96rem; margin: 20px 0 10px; color: var(--text-soft); }

.admin-form { display: flex; flex-direction: column; gap: 14px; margin: 0 0 18px; }
.admin-form label {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: .82rem;
  font-weight: 700;
  letter-spacing: .03em;
  color: var(--text-dim);
}
.admin-form textarea {
  min-height: 160px;
  resize: vertical;
  font-family: var(--mono);
  font-size: .86rem;
  line-height: 1.55;
}
.admin-form input[type="file"] {
  padding: 10px;
  font-size: .86rem;
  color: var(--text-soft);
  background: rgba(6,14,28,.5);
  cursor: pointer;
}
.admin-form input[type="file"]::file-selector-button {
  margin-right: 12px;
  padding: 8px 14px;
  border: 1px solid var(--glass-border-strong);
  border-radius: var(--r-sm);
  background: var(--accent-grad-soft);
  color: var(--cyan-soft);
  font-weight: 700;
  cursor: pointer;
}
.admin-form .full { width: 100%; }

.form-actions { display: flex; flex-direction: row; align-items: center; flex-wrap: wrap; gap: 12px; }
.form-msg { font-size: .86rem; color: var(--text-dim); }
.form-msg.ok { color: var(--ok); }
.form-msg.error {
  color: var(--danger);
  background: transparent;
  border: none;
  padding: 0;
}

/* 用户表格 */
.users-list { margin-top: 8px; overflow-x: auto; }
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: .86rem;
  min-width: 520px;
}
.data-table thead th {
  position: sticky;
  top: 0;
  text-align: left;
  padding: 10px 12px;
  font-size: .74rem;
  font-weight: 800;
  letter-spacing: .05em;
  text-transform: uppercase;
  color: var(--cyan-soft);
  background: rgba(10,20,38,.9);
  border-bottom: 1px solid var(--glass-border-strong);
}
.data-table tbody td {
  padding: 10px 12px;
  color: var(--text-soft);
  border-bottom: 1px solid rgba(120,190,255,.08);
}
.data-table tbody tr:hover td { background: rgba(42,212,255,.05); }
.data-table .muted { color: var(--text-dim); }
.cell-actions { white-space: nowrap; text-align: right; }

.role-admin { color: var(--cyan-soft); font-weight: 700; }
.role-user { color: var(--text-soft); }

/* 表格内合否 */
.data-table td.pass { color: var(--ok); font-weight: 700; }
.data-table td.fail { color: var(--danger); font-weight: 700; }

/* 统计 */
.stats-body { margin-top: 4px; }
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 12px;
  margin: 0 0 12px;
}
.stat-card {
  padding: 16px;
  text-align: center;
  background: var(--accent-grad-soft);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-md);
  box-shadow: var(--shadow-sm);
}
.stat-value {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.9rem;
  font-weight: 800;
  color: var(--cyan-soft);
  line-height: 1.1;
  text-shadow: 0 0 16px rgba(42,212,255,.3);
}
.stat-label { margin-top: 4px; font-size: .8rem; color: var(--text-dim); }

/* =============================================================================
   动画
   ============================================================================= */
@keyframes fade-up {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }
}

/* =============================================================================
   响应式 ≥600px (平板竖屏)
   ============================================================================= */
@media (min-width: 600px) {
  main { padding: 22px 20px calc(48px + env(safe-area-inset-bottom)); }

  .nav-brand { font-size: 1.1rem; }

  .card, .admin-section, .exam-card { padding: 22px; }

  .login-card { padding: 34px 30px; }
  .login-title { font-size: 1.7rem; }

  .home-title, .history-title, .view-title { font-size: 1.7rem; }

  /* 章节双列 */
  .chap-list {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    max-height: none;
  }

  /* 操作区: 标记与上一/下一同排 */
  .exam-actions {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
  .exam-prevnext { flex: 0 0 auto; }
  .exam-prevnext .btn { min-width: 120px; }

  .exam-timer { font-size: 1.22rem; }
}

/* =============================================================================
   响应式 ≥960px (桌面)
   ============================================================================= */
@media (min-width: 960px) {
  main { max-width: 860px; padding: 28px 24px 64px; }

  .login-wrap { min-height: calc(100vh - 110px); }

  /* 章节三列 */
  .chap-list { grid-template-columns: repeat(3, 1fr); }

  /* 题号导航更密 */
  .exam-nav-grid { grid-template-columns: repeat(auto-fill, minmax(48px, 1fr)); }

  /* 统计四列 */
  .stats-grid { grid-template-columns: repeat(4, 1fr); }

  /* 悬停微交互更明显(指针设备) */
  .history-card:hover { box-shadow: var(--shadow-lg), 0 0 30px rgba(42,212,255,.16); }
}

/* =============================================================================
   prefers-color-scheme: dark — 本设计本身为深色科技风。
   显式声明以确保在 dark 偏好下清晰、对比充足, 并校正个别色彩。
   ============================================================================= */
@media (prefers-color-scheme: dark) {
  :root {
    --text: #eef5ff;
    --text-soft: #b6cbe8;
    --text-dim: #7d93b6;
    --glass: rgba(22, 40, 70, 0.6);
    --glass-border: rgba(120, 190, 255, 0.2);
  }
  /* 加强题干/选项对比, 保证暗环境下可读 */
  .exam-stem { color: #f3f8ff; }
  .exam-option { color: #c7d8f2; }
}

/* 浅色系统偏好下仍维持深色科技风(本应用为单一深色主题), 仅保证文字不被系统反色 */
@media (prefers-color-scheme: light) {
  body { color: var(--text); }
}