:root {
  --ink: #173f3d;
  --ink-strong: #0b3231;
  --paper: #fbf7ec;
  --paper-deep: #f3ecd9;
  --card: #fffdf7;
  --line: #d8cdb5;
  --line-strong: #bcae8e;
  --gold: #b38a35;
  --gold-soft: #f1dfac;
  --muted: #6d736f;
  --danger: #a54232;
  --success: #2d725c;
  --shadow: 0 20px 55px -40px rgba(21, 56, 52, 0.48);
  --radius: 18px;
  color-scheme: light;
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink-strong);
  background:
    linear-gradient(rgba(179, 138, 53, .045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(179, 138, 53, .045) 1px, transparent 1px),
    var(--paper);
  background-size: 34px 34px;
}

button, input, textarea, select { font: inherit; }
a { color: inherit; }

.hidden { display: none !important; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 14px max(22px, calc((100vw - 1180px) / 2));
  border-bottom: 1px solid rgba(188, 174, 142, .7);
  background: rgba(255, 253, 247, .93);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: 13px;
  color: var(--paper);
  background: var(--ink);
  font-family: Georgia, serif;
  font-size: 20px;
  box-shadow: 0 8px 20px -14px var(--ink);
}

.brand strong, .brand small { display: block; }
.brand strong { font-size: 14px; }
.brand small { margin-top: 2px; color: var(--muted); font-size: 12px; }

.teacher-link, .text-button {
  border: 0;
  color: var(--muted);
  background: transparent;
  font-weight: 650;
  text-decoration: none;
  cursor: pointer;
}
.teacher-link:hover, .text-button:hover { color: var(--ink); }

.page-shell, .teacher-shell {
  width: min(1180px, calc(100% - 36px));
  margin: 0 auto;
  padding: 34px 0 64px;
}

.landing-grid, .quiz-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 310px;
  gap: 30px;
  align-items: start;
}

.eyebrow-row { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.eyebrow { color: var(--ink); font-weight: 750; font-size: 13px; }
.time-hint { color: var(--muted); font-size: 13px; }

h1, h2, h3, p { margin-top: 0; }
h1 {
  margin: 14px 0 12px;
  max-width: 760px;
  font-family: Georgia, "Songti SC", serif;
  font-size: clamp(32px, 5vw, 52px);
  line-height: 1.08;
  letter-spacing: -.025em;
}
h2 { font-family: Georgia, "Songti SC", serif; }
.lead { max-width: 720px; color: var(--muted); line-height: 1.8; }

.card, .question-card, .loading-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 253, 247, .96);
  box-shadow: var(--shadow);
}

.identity-card { margin-top: 30px; overflow: hidden; }
.card-heading { padding: 22px 24px 16px; border-bottom: 1px solid var(--line); background: rgba(243, 236, 217, .45); }
.card-heading h2 { margin-bottom: 6px; font-size: 22px; }
.card-heading p { margin-bottom: 0; color: var(--muted); font-size: 14px; }
.card-body { padding: 22px 24px; }
.form-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }

label { display: block; font-size: 13px; font-weight: 700; }
input, textarea, select {
  width: 100%;
  margin-top: 7px;
  border: 1px solid var(--line-strong);
  border-radius: 11px;
  color: var(--ink-strong);
  background: #fffefa;
  outline: none;
}
input, select { height: 42px; padding: 0 12px; }
textarea { min-height: 96px; padding: 12px; resize: vertical; line-height: 1.6; }
input:focus, textarea:focus, select:focus { border-color: var(--ink); box-shadow: 0 0 0 3px rgba(23, 63, 61, .12); }
.code-input { font-family: "SFMono-Regular", Consolas, monospace; font-size: 13px; }

.form-footer, .quiz-actions, .dashboard-title-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-top: 20px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}
.hint { color: var(--muted); font-size: 13px; }
.error { margin-top: 14px; color: var(--danger); font-size: 14px; }
.success { color: var(--success); }

.primary-button, .secondary-button {
  display: inline-flex;
  min-height: 42px;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 0 18px;
  border-radius: 11px;
  font-weight: 750;
  cursor: pointer;
  text-decoration: none;
}
.primary-button { border: 1px solid var(--ink); color: white; background: var(--ink); }
.primary-button:hover { background: var(--ink-strong); }
.secondary-button { border: 1px solid var(--line-strong); color: var(--ink); background: #fffefa; }
.secondary-button:hover { background: var(--paper-deep); }
button:disabled { cursor: wait; opacity: .6; }

.goal-card { padding: 22px; color: white; background: var(--ink); border-color: var(--ink); }
.goal-card h2 { margin-bottom: 8px; }
.goal-card p { color: rgba(255,255,255,.7); font-size: 13px; }
.goal-list { display: grid; gap: 12px; margin: 20px 0 0; padding: 0; list-style: none; }
.goal-list li::before { content: "◆"; margin-right: 10px; color: var(--gold-soft); font-size: 10px; }
.note-card { margin-top: 16px; padding: 20px; border-style: dashed; box-shadow: none; color: var(--muted); line-height: 1.65; }
.note-card strong { color: var(--ink); }

.quiz-main { min-width: 0; }
.quiz-top { margin-bottom: 20px; }
.progress-row { display: flex; justify-content: space-between; gap: 16px; align-items: end; }
.progress-row h1 { margin: 5px 0 0; font-size: clamp(27px, 4vw, 38px); }
.progress-track { height: 7px; margin-top: 15px; overflow: hidden; border-radius: 99px; background: var(--paper-deep); }
.progress-bar { height: 100%; width: 0; border-radius: inherit; background: linear-gradient(90deg, var(--ink), var(--gold)); transition: width .2s ease; }
.question-list { display: grid; gap: 16px; }
.question-card { padding: 22px; box-shadow: none; }
.question-meta { display: flex; justify-content: space-between; gap: 14px; color: var(--ink); font-size: 12px; font-weight: 800; letter-spacing: .06em; }
.question-card h2 { margin: 10px 0 6px; font-family: inherit; font-size: 18px; line-height: 1.5; }
.question-detail { color: var(--muted); font-size: 13px; line-height: 1.6; }
.option-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; margin-top: 16px; }
.option {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 11px;
  background: #fffefa;
  cursor: pointer;
  font-weight: 500;
}
.option:hover { border-color: var(--ink); }
.option input { width: 16px; height: 16px; margin: 0; accent-color: var(--ink); }
.file-upload-box { margin-top: 16px; padding: 18px; border: 1px dashed var(--gold); border-radius: 13px; background: rgba(241, 223, 172, .24); }
.file-upload-box input { height: auto; margin: 0; padding: 10px; background: white; }
.upload-status { margin: 10px 0 0; color: var(--muted); font-size: 13px; }
.upload-status.error { margin-top: 10px; }

.data-card { position: sticky; top: 90px; overflow: hidden; box-shadow: none; }
.data-card-highlight { border: 2px solid var(--gold); background: linear-gradient(180deg, rgba(241, 223, 172, .58), var(--card) 38%); box-shadow: 0 18px 42px -30px rgba(179, 138, 53, .9); }
.data-focus-badge { display: inline-flex; margin: 14px 18px 0; padding: 5px 9px; border-radius: 99px; color: #fff; background: var(--gold); font-size: 12px; font-weight: 800; letter-spacing: .04em; }
.data-card h2 { padding: 18px 18px 5px; margin-bottom: 0; font-size: 17px; }
.data-card p { padding: 0 18px 12px; margin: 0; color: var(--muted); font-size: 12px; }
table { width: 100%; border-collapse: collapse; }
th, td { padding: 10px 12px; border-top: 1px solid var(--line); text-align: left; font-size: 13px; }
th { color: var(--muted); background: rgba(243,236,217,.5); font-weight: 650; }
.data-card th, .data-card td { padding: 8px 9px; text-align: right; font-family: "SFMono-Regular", Consolas, monospace; font-size: 11px; }
.data-card th:first-child, .data-card td:first-child { text-align: left; }

.result-card { width: min(690px, 100%); margin: 48px auto; padding: 40px; text-align: center; }
.result-seal { display: grid; width: 66px; height: 66px; margin: 0 auto 18px; place-items: center; border-radius: 50%; color: white; background: var(--success); font-size: 30px; }
.confirmation { width: min(390px, 100%); margin: 22px auto; padding: 18px; border: 1px dashed var(--line-strong); border-radius: 13px; background: var(--paper-deep); }
.confirmation strong { display: block; margin-top: 7px; color: var(--ink); font-family: monospace; font-size: 20px; letter-spacing: .1em; }

.login-card { width: min(440px, 100%); margin: 50px auto; padding: 28px; }
.login-card h1 { font-size: 34px; }
.login-card .primary-button { width: 100%; margin-top: 18px; }
.teacher-toolbar { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.teacher-toolbar select { width: auto; min-width: 220px; margin: 0; }
.metric-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; margin: 22px 0 34px; }
.metric-card { padding: 18px; box-shadow: none; }
.metric-card small { color: var(--muted); }
.metric-card strong { display: block; margin-top: 8px; font-family: Georgia, serif; font-size: 30px; }
.section-heading { margin: 30px 0 14px; }
.section-heading h2 { margin-bottom: 5px; }
.section-heading p { margin-bottom: 0; color: var(--muted); font-size: 13px; }
.stat-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 10px; }
.stat-card { padding: 14px; box-shadow: none; }
.stat-card small { color: var(--muted); }
.stat-card strong { display: block; margin: 14px 0 8px; font-size: 24px; }
.mini-track { height: 5px; overflow: hidden; border-radius: 99px; background: var(--paper-deep); }
.mini-bar { height: 100%; background: var(--ink); }
.review-list { display: grid; gap: 12px; }
.review-card { padding: 18px; box-shadow: none; }
.review-answer { margin: 14px 0; padding: 13px; overflow-wrap: anywhere; border-radius: 10px; background: var(--paper-deep); white-space: pre-wrap; font-family: monospace; font-size: 13px; }
.review-form { display: grid; grid-template-columns: 120px minmax(0, 1fr) auto; gap: 12px; align-items: end; }
.review-form textarea { min-height: 64px; }
.table-card { overflow-x: auto; box-shadow: none; }
.table-card table { min-width: 760px; }
.empty { padding: 28px; border: 1px dashed var(--line-strong); border-radius: 14px; color: var(--muted); text-align: center; }
.loading-card { width: min(520px, 100%); margin: 50px auto; padding: 28px; color: var(--muted); text-align: center; }

.hub-hero { padding: 32px 0 20px; }
.hub-hero h1 { margin-bottom: 16px; }
.compact-hero h1 { font-size: clamp(30px, 4.5vw, 44px); }
.series-grid, .class-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; margin-top: 22px; }
.series-card, .class-card { padding: 24px; box-shadow: none; }
.series-card h2, .class-card h2 { margin: 10px 0 8px; }
.series-card p, .class-card p { min-height: 48px; color: var(--muted); line-height: 1.65; }
.series-index { display: inline-grid; width: 36px; height: 36px; place-items: center; border-radius: 11px; color: white; background: var(--ink); font-family: Georgia, serif; }
.tag-row { display: flex; gap: 8px; flex-wrap: wrap; margin: 14px 0 20px; }
.tag-row span, .class-label, .roster-chip { display: inline-flex; align-items: center; padding: 5px 10px; border-radius: 99px; color: var(--ink); background: var(--paper-deep); font-size: 12px; font-weight: 750; }
.class-card-top, .review-card-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.status-pill { display: inline-flex; padding: 5px 9px; border-radius: 99px; color: var(--success); background: rgba(45, 114, 92, .1); font-size: 12px; font-weight: 750; }
.status-pill.closed, .class-card.is-closed .status-pill { color: var(--muted); background: var(--paper-deep); }
.class-card.is-closed { opacity: .7; }
.class-meta { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin-bottom: 18px; }
.class-meta span { padding: 9px; border: 1px solid var(--line); border-radius: 10px; color: var(--muted); text-align: center; font-size: 12px; }
.breadcrumb { margin-bottom: 4px; color: var(--muted); font-size: 13px; }
.breadcrumb a { text-decoration: none; }
.breadcrumb a:hover { color: var(--ink); }
.session-card { border-color: rgba(45, 114, 92, .45); }
.identity-confirm-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.identity-confirm-grid div { padding: 13px; border-radius: 11px; background: var(--paper-deep); }
.identity-confirm-grid small, .student-line { color: var(--muted); }
.identity-confirm-grid strong { display: block; margin-top: 5px; }
.empty-state { text-align: center; }
.student-line { margin: 8px 0 0; font-size: 13px; }

.result-shell { width: min(820px, 100%); margin: 30px auto; }
.result-summary { padding: 32px; text-align: center; }
.result-summary h1 { margin-left: auto; margin-right: auto; font-size: clamp(28px, 4vw, 40px); }
.pending-seal { background: var(--gold); }
.notice-banner { display: flex; align-items: center; gap: 12px; margin: 16px 0; padding: 14px 16px; border: 1px solid rgba(45, 114, 92, .35); border-radius: 12px; color: var(--ink); background: rgba(45, 114, 92, .08); }
.notice-banner span { color: var(--muted); font-size: 13px; }
.warning-banner { border-color: rgba(179, 138, 53, .55); background: rgba(241, 223, 172, .35); }
.result-list { display: grid; gap: 12px; }
.result-item { padding: 20px; box-shadow: none; }
.pending-item { border-left: 5px solid var(--gold); }
.incorrect-item { border-left: 5px solid var(--danger); }
.incorrect-label { margin: 10px 0; color: var(--danger); font-weight: 800; }
.result-actions, .review-actions { display: flex; justify-content: center; gap: 12px; margin-top: 20px; }
.appeal-form { margin-top: 14px; padding-top: 14px; border-top: 1px solid var(--line); }

.metric-grid { grid-template-columns: repeat(5, 1fr); }
.roster-panel { padding: 22px; box-shadow: none; }
.roster-summary { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 16px; }
.roster-import-row { display: grid; grid-template-columns: minmax(260px, 1fr) auto auto; gap: 12px; align-items: end; }
.file-label input { padding: 8px; height: auto; }
.inline-loading { padding: 18px 0; color: var(--muted); }
.import-preview { margin-top: 18px; padding: 18px; border: 1px solid rgba(45, 114, 92, .35); border-radius: 13px; background: rgba(45, 114, 92, .04); }
.import-preview.has-errors { border-color: rgba(165, 66, 50, .4); background: rgba(165, 66, 50, .04); }
.import-preview .table-card { max-height: 320px; margin: 14px 0; overflow: auto; background: white; }
.error-list { color: var(--danger); }
.warning-list { color: #8a641f; }
.review-card-head { margin-bottom: 12px; }
.teacher-evidence { margin: 12px 0; padding: 12px 14px; border: 1px dashed var(--line-strong); border-radius: 11px; color: var(--muted); font-size: 13px; }
.teacher-evidence summary { color: var(--ink); cursor: pointer; font-weight: 750; }
.teacher-evidence p { margin: 10px 0 0; line-height: 1.6; }
.appeal-note { padding: 12px 14px; border-radius: 11px; background: var(--paper-deep); }
.appeal-note p { margin: 5px 0 0; }
.review-decision { display: grid; grid-template-columns: minmax(0, 1fr) auto auto; gap: 10px; align-items: end; }
.review-decision textarea { min-height: 72px; }
.history-panel { margin-top: 18px; box-shadow: none; overflow: hidden; }
.history-panel summary { padding: 18px 20px; cursor: pointer; font-weight: 750; }

@media (max-width: 920px) {
  .landing-grid, .quiz-grid { grid-template-columns: 1fr; }
  .data-card { position: static; }
  .metric-grid { grid-template-columns: repeat(2, 1fr); }
  .stat-grid { grid-template-columns: repeat(2, 1fr); }
  .roster-import-row { grid-template-columns: 1fr 1fr; }
  .roster-import-row .file-label { grid-column: 1 / -1; }
}

@media (max-width: 640px) {
  .site-header { padding: 12px 16px; }
  .brand-mark { width: 38px; height: 38px; }
  .page-shell, .teacher-shell { width: min(100% - 24px, 1180px); padding-top: 24px; }
  .form-grid, .option-grid, .metric-grid, .stat-grid, .series-grid, .class-grid, .identity-confirm-grid, .roster-import-row, .review-decision { grid-template-columns: 1fr; }
  .form-footer, .quiz-actions, .dashboard-title-row { align-items: stretch; flex-direction: column; }
  .primary-button, .secondary-button { width: 100%; }
  .review-form { grid-template-columns: 1fr; }
  .result-card { padding: 28px 18px; }
  h1 { font-size: 34px; }
  .class-meta { grid-template-columns: 1fr; }
  .notice-banner, .result-actions, .review-actions { align-items: stretch; flex-direction: column; }
}