:root {
  color-scheme: light;
  --bg: #f6f8fb;
  --panel: #ffffff;
  --panel-soft: #f9fbfd;
  --ink: #14213d;
  --muted: #5d6b82;
  --line: #dce4ee;
  --brand: #0f766e;
  --brand-dark: #115e59;
  --blue: #2563eb;
  --amber: #b45309;
  --rose: #be123c;
  --green: #15803d;
  --shadow: 0 18px 40px rgba(20, 33, 61, 0.08);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
}

.noscript {
  padding: 14px;
  background: #fff1f2;
  color: #9f1239;
  text-align: center;
  font-weight: 800;
}

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

button {
  cursor: pointer;
}

.app-shell {
  min-height: 100vh;
}

.offline-page {
  min-height: 100vh;
  display: grid;
  place-content: center;
  gap: 18px;
  padding: 24px;
  text-align: center;
}

.offline-page .brand-mark {
  margin: 0 auto;
  background: var(--brand);
  color: #fff;
}

.offline-page h1 {
  margin: 0;
  font-size: clamp(32px, 8vw, 56px);
}

.offline-page p {
  max-width: 560px;
  margin: 0 auto;
  color: var(--muted);
  line-height: 1.7;
}

.login-page {
  min-height: 100vh;
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(360px, 0.9fr);
}

.login-hero {
  padding: 48px clamp(24px, 6vw, 88px);
  display: flex;
  flex-direction: column;
  justify-content: center;
  background:
    linear-gradient(145deg, rgba(9, 30, 43, 0.96), rgba(15, 118, 110, 0.88)),
    radial-gradient(circle at 18% 20%, rgba(204, 251, 241, 0.22), transparent 32%),
    radial-gradient(circle at 82% 78%, rgba(219, 234, 254, 0.18), transparent 28%);
  color: #fff;
}

.brand-mark {
  width: 48px;
  height: 48px;
  display: block;
  object-fit: contain;
}

.login-hero h1 {
  max-width: 760px;
  margin: 36px 0 20px;
  font-size: clamp(38px, 5vw, 72px);
  line-height: 1;
  letter-spacing: 0;
}

.login-hero p {
  max-width: 620px;
  margin: 0;
  color: rgba(255, 255, 255, 0.86);
  font-size: 18px;
  line-height: 1.7;
}

.path-strip {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  max-width: 720px;
  margin-top: 34px;
}

.path-chip {
  border: 1px solid rgba(255, 255, 255, 0.26);
  padding: 14px;
  background: rgba(255, 255, 255, 0.1);
}

.path-chip strong {
  display: block;
  margin-bottom: 4px;
}

.path-chip span {
  color: rgba(255, 255, 255, 0.78);
  font-size: 14px;
}

.login-panel-wrap {
  display: grid;
  place-items: center;
  padding: 28px;
}

.login-panel {
  width: min(100%, 440px);
  background: var(--panel);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  padding: 28px;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--brand);
  font-size: 12px;
  text-transform: uppercase;
  font-weight: 800;
  letter-spacing: 0.08em;
}

.login-panel h2,
.section-title h2 {
  margin: 0;
  font-size: 28px;
  letter-spacing: 0;
}

.login-panel .muted,
.section-title p,
.muted {
  color: var(--muted);
  line-height: 1.6;
}

.form-grid {
  display: grid;
  gap: 14px;
  margin-top: 22px;
}

.field {
  display: grid;
  gap: 7px;
}

.field label {
  font-size: 13px;
  font-weight: 700;
  color: #334155;
}

.field input,
.field select,
.field textarea {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--line);
  padding: 10px 12px;
  background: #fff;
  color: var(--ink);
}

.field textarea {
  min-height: 88px;
  resize: vertical;
}

.primary-btn,
.secondary-btn,
.ghost-btn,
.danger-btn {
  min-height: 42px;
  border: 1px solid transparent;
  padding: 10px 14px;
  font-weight: 800;
}

.primary-btn {
  background: var(--brand);
  color: #fff;
}

.primary-btn:hover {
  background: var(--brand-dark);
}

.secondary-btn {
  background: #e8f5f3;
  color: var(--brand-dark);
}

.ghost-btn {
  background: #fff;
  color: var(--ink);
  border-color: var(--line);
}

.danger-btn {
  background: #fff1f2;
  color: var(--rose);
  border-color: #fecdd3;
}

.app-layout {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 276px minmax(0, 1fr);
}

.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  padding: 22px 18px;
  background: #0b172a;
  color: #e5edf7;
  display: flex;
  flex-direction: column;
}

.sidebar-top {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 24px;
}

.sidebar .brand-mark {
  width: 40px;
  height: 40px;
}

.brand-copy strong,
.brand-copy span {
  display: block;
}

.brand-copy span {
  color: #9fb0c8;
  font-size: 12px;
}

.nav-list {
  display: grid;
  gap: 6px;
}

.nav-btn {
  width: 100%;
  border: 0;
  text-align: left;
  min-height: 44px;
  padding: 10px 12px;
  background: transparent;
  color: #cbd5e1;
  font-weight: 750;
}

.nav-btn:hover,
.nav-btn.active {
  background: #152641;
  color: #fff;
}

.sidebar-foot {
  margin-top: auto;
  display: grid;
  gap: 12px;
}

.role-pill {
  border: 1px solid #263b5e;
  padding: 12px;
  background: #111f36;
}

.role-pill span {
  display: block;
  color: #9fb0c8;
  font-size: 12px;
  margin-bottom: 3px;
}

.main {
  min-width: 0;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 5;
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 16px 28px;
  background: rgba(246, 248, 251, 0.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}

.mobile-menu {
  display: none;
}

.topbar h1 {
  margin: 0;
  font-size: 22px;
  letter-spacing: 0;
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.status-dot {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  min-height: 30px;
  padding: 5px 10px;
  border: 1px solid var(--line);
  background: #fff;
  color: var(--muted);
  font-size: 12px;
  font-weight: 800;
}

.status-dot::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: var(--green);
}

.status-dot.offline::before {
  background: var(--rose);
}

.content {
  padding: 28px;
}

.section-title {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 20px;
}

.grid {
  display: grid;
  gap: 16px;
}

.grid.cols-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid.cols-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid.cols-4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.card,
.stat-card,
.table-card {
  background: var(--panel);
  border: 1px solid var(--line);
  box-shadow: 0 8px 24px rgba(20, 33, 61, 0.04);
}

.card {
  padding: 18px;
}

.stat-card {
  padding: 16px;
}

.stat-card span {
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

.stat-card strong {
  display: block;
  margin-top: 8px;
  font-size: 26px;
  letter-spacing: 0;
}

.card-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 12px;
}

.card h3 {
  margin: 0;
  font-size: 18px;
  letter-spacing: 0;
}

.card p {
  margin: 8px 0 0;
  color: var(--muted);
  line-height: 1.55;
}

.badge {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  padding: 4px 9px;
  background: #edf2f7;
  color: #334155;
  font-size: 12px;
  font-weight: 800;
  white-space: nowrap;
}

.badge.green {
  background: #dcfce7;
  color: #166534;
}

.badge.blue {
  background: #dbeafe;
  color: #1d4ed8;
}

.badge.amber {
  background: #fef3c7;
  color: #92400e;
}

.badge.rose {
  background: #ffe4e6;
  color: #be123c;
}

.progress-bar {
  width: 100%;
  height: 8px;
  margin-top: 14px;
  overflow: hidden;
  background: #e2e8f0;
}

.progress-bar span {
  display: block;
  height: 100%;
  background: var(--brand);
}

.course-card {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.course-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 14px;
}

.split-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  gap: 16px;
}

.list {
  display: grid;
  gap: 10px;
}

.list-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 13px;
  border: 1px solid var(--line);
  background: var(--panel-soft);
}

.list-item strong,
.list-item span {
  display: block;
}

.list-item span {
  color: var(--muted);
  font-size: 13px;
  margin-top: 3px;
}

.test-screen {
  display: grid;
  gap: 16px;
}

.test-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
}

.timer {
  min-width: 86px;
  text-align: center;
  padding: 9px 12px;
  background: #0b172a;
  color: #fff;
  font-weight: 900;
}

.question-card {
  padding: 22px;
}

.question-card h3 {
  font-size: 20px;
  line-height: 1.4;
}

.equation {
  display: inline-block;
  padding: 2px 6px;
  border: 1px solid #cbd5e1;
  background: #f8fafc;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 0.95em;
}

.question-media {
  margin: 14px 0;
  border: 1px solid var(--line);
  background: #fff;
  padding: 10px;
}

.question-media img {
  display: block;
  max-width: 100%;
  max-height: 320px;
  object-fit: contain;
}

.options {
  display: grid;
  gap: 10px;
  margin-top: 18px;
}

.option-btn {
  width: 100%;
  min-height: 48px;
  border: 1px solid var(--line);
  padding: 12px 14px;
  background: #fff;
  color: var(--ink);
  text-align: left;
  font-weight: 700;
}

.option-btn.active {
  border-color: var(--brand);
  background: #ecfdf5;
  color: var(--brand-dark);
}

.answer-key-item {
  align-items: flex-start;
}

.answer-key-item .question-media {
  max-width: 420px;
}

.question-nav {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.q-dot {
  width: 38px;
  height: 38px;
  border: 1px solid var(--line);
  background: #fff;
  font-weight: 800;
}

.q-dot.active {
  border-color: #0b172a;
  background: #0b172a;
  color: #fff;
}

.q-dot.answered {
  border-color: var(--brand);
  background: #ccfbf1;
  color: var(--brand-dark);
}

.table-card {
  overflow: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 720px;
}

th,
td {
  padding: 13px 14px;
  border-bottom: 1px solid var(--line);
  text-align: left;
}

th {
  color: #475569;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  background: #f8fafc;
}

.empty {
  border: 1px dashed #b8c4d4;
  padding: 24px;
  background: #fff;
  color: var(--muted);
  text-align: center;
}

.notice {
  padding: 14px;
  border: 1px solid #bae6fd;
  background: #eff6ff;
  color: #1e3a8a;
}

.admin-picker-list {
  max-height: none;
}

.tab-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 18px 0 14px;
}

.tab-btn {
  min-height: 38px;
  padding: 8px 14px;
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
  font-weight: 800;
  font-size: 13px;
}

.tab-btn.active {
  border-color: var(--brand);
  background: #ecfdf5;
  color: var(--brand-dark);
}

.tab-count {
  display: inline-flex;
  margin-left: 6px;
  min-width: 22px;
  justify-content: center;
  padding: 2px 6px;
  background: #e2e8f0;
  font-size: 11px;
}

.tab-btn.active .tab-count {
  background: #ccfbf1;
}

.login-user-list {
  display: grid;
  gap: 12px;
  max-height: 52vh;
  overflow: auto;
  padding-right: 4px;
}

.login-user-card {
  border: 1px solid var(--line);
  padding: 14px;
  background: var(--panel-soft);
}

.login-user-card.blocked {
  opacity: 0.72;
}

.login-user-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 12px;
  align-items: start;
}

.avatar-chip {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  background: #0b172a;
  color: #fff;
  font-weight: 900;
  font-size: 13px;
}

.login-user-head strong,
.login-user-head span {
  display: block;
}

.login-user-head span {
  color: var(--muted);
  font-size: 13px;
  margin-top: 2px;
}

.login-user-meta {
  display: grid;
  gap: 6px;
  margin: 12px 0;
  font-size: 13px;
  color: var(--muted);
}

.login-user-meta strong {
  color: var(--ink);
}

.role-pill-sub {
  display: block;
  margin-top: 4px;
  color: #9fb0c8;
  font-size: 12px;
  font-weight: 600;
}

.user-admin-panel .user-list-row {
  align-items: flex-start;
}

.detail-grid {
  display: grid;
  gap: 12px;
}

.detail-grid > div {
  display: grid;
  gap: 4px;
}

.detail-grid span {
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.drawer-backdrop {
  display: none;
}

@media (max-width: 980px) {
  .login-page {
    grid-template-columns: 1fr;
  }

  .login-hero {
    min-height: 48vh;
  }

  .app-layout {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    z-index: 20;
    width: min(86vw, 320px);
    transform: translateX(-105%);
    transition: transform 180ms ease;
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .drawer-backdrop {
    position: fixed;
    inset: 0;
    z-index: 19;
    display: none;
    background: rgba(15, 23, 42, 0.42);
  }

  .drawer-backdrop.open {
    display: block;
  }

  .mobile-menu {
    display: inline-flex;
  }

  .grid.cols-4,
  .grid.cols-3,
  .grid.cols-2,
  .split-panel {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .login-hero,
  .content,
  .topbar {
    padding-left: 16px;
    padding-right: 16px;
  }

  .path-strip {
    grid-template-columns: 1fr;
  }

  .login-panel-wrap {
    padding: 16px;
  }

  .section-title,
  .topbar {
    align-items: flex-start;
    flex-direction: column;
  }

  .topbar-actions {
    width: 100%;
    justify-content: space-between;
  }
}