:root {
  --ink: #06165c;
  --ink-soft: #52658e;
  --muted: #7a89aa;
  --blue: #0567ff;
  --blue-dark: #004fd8;
  --blue-soft: #eaf3ff;
  --blue-wash: #f4f9ff;
  --green: #10914a;
  --green-soft: #e9f8ef;
  --teal: #0798aa;
  --teal-soft: #e8f8fa;
  --violet: #5f49d9;
  --violet-soft: #f0edff;
  --amber: #c97900;
  --amber-soft: #fff5dd;
  --red: #d93d3d;
  --red-soft: #ffecec;
  --line: #dbe6f6;
  --line-strong: #bed0ec;
  --panel: rgba(255, 255, 255, 0.96);
  --shadow: 0 18px 46px rgba(29, 82, 151, 0.13);
  --shadow-soft: 0 12px 28px rgba(35, 83, 146, 0.1);
  font-family: "Inter", "Segoe UI", Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  background: linear-gradient(135deg, #ffffff 0%, #f7fbff 46%, #eaf3ff 100%);
}

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

button {
  cursor: pointer;
}

img {
  display: block;
  max-width: 100%;
}

.hidden {
  display: none !important;
}

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

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  height: 92px;
  padding: 0 50px;
  background: rgba(255, 255, 255, 0.98);
  border-bottom: 1px solid var(--line);
}

.brand {
  display: flex;
  align-items: center;
  min-width: 260px;
  text-decoration: none;
}

.brand-logo {
  width: 230px;
  height: 68px;
  object-fit: contain;
  object-position: left center;
}

.main-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  flex: 1;
  gap: clamp(18px, 2.8vw, 42px);
}

.nav-link {
  height: 92px;
  padding: 2px 0 0;
  border: 0;
  border-bottom: 3px solid transparent;
  color: var(--ink);
  background: transparent;
  font-weight: 700;
  white-space: nowrap;
}

.nav-link.active {
  color: var(--blue);
  border-color: var(--blue);
}

.user-tools {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 14px;
  min-width: 230px;
}

.divider {
  width: 1px;
  height: 34px;
  background: var(--line);
}

.icon-button,
.avatar,
.close-button,
.video-play-button {
  position: relative;
  display: inline-grid;
  place-items: center;
  border: 0;
  background: transparent;
}

.icon-button,
.avatar {
  width: 42px;
  height: 42px;
  border-radius: 50%;
}

.bell-button::before {
  content: "";
  width: 15px;
  height: 17px;
  border: 2px solid var(--ink);
  border-bottom-width: 3px;
  border-radius: 10px 10px 5px 5px;
}

.bell-button::after {
  content: "";
  position: absolute;
  top: 30px;
  width: 6px;
  height: 2px;
  border-radius: 99px;
  background: var(--ink);
}

.avatar {
  border: 1px solid var(--line);
  background: #fff;
}

.avatar::before {
  content: "";
  position: absolute;
  top: 10px;
  width: 9px;
  height: 9px;
  border: 2px solid var(--ink);
  border-radius: 50%;
}

.avatar::after {
  content: "";
  position: absolute;
  top: 24px;
  width: 18px;
  height: 10px;
  border: 2px solid var(--ink);
  border-bottom: 0;
  border-radius: 12px 12px 0 0;
}

.profile-button {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-width: 88px;
  border: 0;
  background: transparent;
  color: var(--ink);
  font-weight: 800;
  white-space: nowrap;
}

.chevron {
  width: 9px;
  height: 9px;
  border-right: 2px solid var(--ink);
  border-bottom: 2px solid var(--ink);
  transform: rotate(45deg) translateY(-2px);
}

.view {
  min-height: calc(100vh - 92px);
}

.page-surface {
  position: relative;
  overflow: hidden;
}

.page-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    linear-gradient(145deg, rgba(255, 255, 255, 0.98) 0%, rgba(250, 253, 255, 0.96) 44%, rgba(230, 242, 255, 0.92) 100%);
}

.page-bg::before {
  content: "";
  position: absolute;
  top: -120px;
  right: -80px;
  width: 56vw;
  height: 520px;
  transform: skewY(-13deg);
  background:
    repeating-linear-gradient(
      164deg,
      rgba(255, 255, 255, 0) 0,
      rgba(255, 255, 255, 0) 40px,
      rgba(255, 255, 255, 0.72) 42px,
      rgba(255, 255, 255, 0.72) 44px
    ),
    linear-gradient(130deg, rgba(207, 226, 250, 0.15), rgba(155, 195, 245, 0.45));
  border-left: 1px solid rgba(255, 255, 255, 0.8);
}

.hero-section,
.content-section,
.detail-container,
.player-container {
  position: relative;
  z-index: 1;
}

.hero-section {
  min-height: 300px;
  padding: 62px 80px 72px;
}

.hero-copy {
  max-width: 850px;
}

.hero-copy h1 {
  margin: 0;
  color: var(--ink);
  font-size: clamp(2.2rem, 4vw, 4.1rem);
  line-height: 1.04;
  letter-spacing: 0;
}

.hero-copy p {
  max-width: 610px;
  margin: 24px 0 0;
  color: #40547f;
  font-size: clamp(1.05rem, 1.4vw, 1.35rem);
  line-height: 1.65;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 28px;
}

.primary-button,
.outline-button,
.text-button,
.chip-button,
.page-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  min-height: 44px;
  border-radius: 8px;
  font-weight: 800;
  text-decoration: none;
  transition: transform 160ms ease, box-shadow 160ms ease, border-color 160ms ease, background 160ms ease;
}

.primary-button {
  border: 1px solid var(--blue);
  color: #fff;
  background: linear-gradient(180deg, #1174ff 0%, #005bed 100%);
  box-shadow: 0 12px 24px rgba(5, 103, 255, 0.22);
  padding: 0 24px;
}

.outline-button {
  border: 1px solid var(--blue);
  color: var(--blue);
  background: #fff;
  padding: 0 22px;
}

.text-button {
  border: 0;
  color: var(--blue);
  background: transparent;
  padding: 0 4px;
  white-space: nowrap;
}

.primary-button:hover,
.outline-button:hover,
.text-button:hover,
.chip-button:hover,
.page-button:hover {
  transform: translateY(-1px);
}

.primary-button.full {
  width: 100%;
}

.play-mark {
  width: 0;
  height: 0;
  border-top: 6px solid transparent;
  border-bottom: 6px solid transparent;
  border-left: 9px solid currentColor;
}

.category-strip {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: repeat(5, minmax(190px, 1fr));
  gap: 16px;
  margin: -26px auto 0;
  padding: 0 74px;
}

.category-card {
  display: grid;
  grid-template-columns: 76px 1fr 20px;
  align-items: center;
  gap: 18px;
  min-height: 130px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow-soft);
  text-align: left;
}

.category-card strong {
  display: block;
  margin-bottom: 8px;
  font-size: 1rem;
  line-height: 1.35;
}

.category-card span:last-child {
  color: var(--ink-soft);
  font-size: 0.82rem;
  line-height: 1.35;
}

.category-card .arrow-mark {
  width: 12px;
  height: 12px;
  border-top: 2px solid var(--ink);
  border-right: 2px solid var(--ink);
  transform: rotate(45deg);
}

.category-icon {
  position: relative;
  width: 76px;
  height: 76px;
  border-radius: 8px;
  background: linear-gradient(145deg, #0c75ff, #044ed0);
}

.category-icon::before,
.category-icon::after {
  content: "";
  position: absolute;
}

.icon-shield::before {
  inset: 16px 21px 14px;
  border: 3px solid #fff;
  border-radius: 20px 20px 24px 24px;
  clip-path: polygon(50% 0, 100% 14%, 94% 67%, 50% 100%, 6% 67%, 0 14%);
}

.icon-shield::after {
  left: 34px;
  top: 25px;
  width: 10px;
  height: 22px;
  border-right: 3px solid #fff;
  border-bottom: 3px solid #fff;
  transform: rotate(42deg);
}

.icon-leaf {
  background: linear-gradient(145deg, #34b36d, #0f7544);
}

.icon-leaf::before {
  left: 18px;
  top: 18px;
  width: 38px;
  height: 38px;
  border: 3px solid #fff;
  border-radius: 36px 4px 36px 4px;
  transform: rotate(-20deg);
}

.icon-leaf::after {
  left: 19px;
  top: 44px;
  width: 40px;
  height: 3px;
  background: #fff;
  transform: rotate(-32deg);
  border-radius: 99px;
}

.icon-scale {
  background: linear-gradient(145deg, #7565ed, #4d38bf);
}

.icon-scale::before {
  left: 36px;
  top: 14px;
  width: 4px;
  height: 48px;
  background: #fff;
  border-radius: 99px;
  box-shadow: -18px 9px 0 -1px #fff, 18px 9px 0 -1px #fff;
}

.icon-scale::after {
  left: 18px;
  top: 34px;
  width: 40px;
  height: 26px;
  border-left: 3px solid #fff;
  border-right: 3px solid #fff;
  border-bottom: 3px solid #fff;
  transform: perspective(32px) rotateX(38deg);
}

.icon-award {
  background: linear-gradient(145deg, #1677ff, #004cc8);
}

.icon-award::before {
  left: 21px;
  top: 14px;
  width: 34px;
  height: 34px;
  border: 4px solid #fff;
  border-radius: 50%;
}

.icon-award::after {
  left: 25px;
  top: 47px;
  width: 27px;
  height: 22px;
  background: linear-gradient(135deg, transparent 47%, #fff 48% 56%, transparent 57%),
    linear-gradient(45deg, transparent 47%, #fff 48% 56%, transparent 57%);
}

.icon-gear {
  background: linear-gradient(145deg, #1bb4c6, #0a8391);
}

.icon-gear::before {
  left: 19px;
  top: 19px;
  width: 38px;
  height: 38px;
  border: 4px dashed #fff;
  border-radius: 50%;
}

.icon-gear::after {
  left: 31px;
  top: 31px;
  width: 14px;
  height: 14px;
  border: 3px solid #fff;
  border-radius: 50%;
}

.content-section {
  padding: 44px 84px 56px;
}

.courses-page {
  padding-top: 38px;
}

.section-heading {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 22px;
}

.section-heading.compact {
  align-items: center;
  margin-bottom: 16px;
}

.section-heading h1,
.section-heading h2,
.chapter-heading h2,
.panel-heading h2 {
  margin: 0;
  color: var(--ink);
}

.section-heading h1 {
  font-size: clamp(2rem, 3vw, 3rem);
  line-height: 1.08;
}

.section-heading h2,
.chapter-heading h2,
.panel-heading h2 {
  font-size: 1.65rem;
}

.section-heading p,
.panel-heading span,
.breadcrumb,
.lesson-count {
  margin: 8px 0 0;
  color: var(--ink-soft);
  line-height: 1.5;
}

.breadcrumb {
  display: inline-block;
  margin-bottom: 8px;
  color: var(--blue);
  font-weight: 700;
}

.course-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(190px, 1fr));
  gap: 24px;
}

.course-grid.wide {
  grid-template-columns: repeat(4, minmax(220px, 1fr));
}

.course-card {
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 330px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow-soft);
  text-align: left;
  transition: transform 160ms ease, box-shadow 160ms ease, border-color 160ms ease;
}

.course-card:hover {
  transform: translateY(-3px);
  border-color: #b8d0ff;
  box-shadow: var(--shadow);
}

.course-card img {
  width: 100%;
  aspect-ratio: 16 / 8;
  border-radius: 6px;
  object-fit: cover;
}

.course-card h3 {
  margin: 16px 10px 10px;
  color: var(--ink);
  font-size: 1.08rem;
  line-height: 1.35;
}

.course-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 10px;
  color: var(--ink-soft);
  font-size: 0.9rem;
}

.course-card-footer {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 14px;
  margin: auto 10px 10px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.progress-track {
  height: 10px;
  overflow: hidden;
  border-radius: 99px;
  background: #e8eef8;
}

.progress-fill {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, #0567ff, #00a3ff);
}

.status-pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 86px;
  min-height: 30px;
  padding: 0 12px;
  border-radius: 999px;
  color: var(--ink-soft);
  background: #eef3fb;
  font-size: 0.82rem;
  font-weight: 800;
  white-space: nowrap;
}

.status-pill.complete {
  color: var(--green);
  background: var(--green-soft);
}

.status-pill.progress {
  color: var(--blue);
  background: var(--blue-soft);
}

.status-pill.warning {
  color: var(--amber);
  background: var(--amber-soft);
}

.pager {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-top: 26px;
}

.page-button {
  width: 38px;
  height: 38px;
  min-height: 38px;
  border: 1px solid var(--line);
  color: var(--ink);
  background: #fff;
  padding: 0;
}

.page-button.active {
  color: #fff;
  border-color: var(--blue);
  background: var(--blue);
}

.filter-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 10px;
}

.chip-button {
  min-height: 38px;
  border: 1px solid var(--line);
  color: var(--ink);
  background: #fff;
  padding: 0 14px;
}

.chip-button.active {
  color: var(--blue);
  border-color: var(--blue);
  background: var(--blue-soft);
}

.detail-container,
.player-container {
  padding: 26px 84px 56px;
}

.breadcrumb-row {
  display: flex;
  align-items: center;
  gap: 13px;
  min-height: 34px;
  color: var(--ink-soft);
  margin-bottom: 10px;
  font-weight: 700;
}

.breadcrumb-row button {
  border: 0;
  color: var(--blue);
  background: transparent;
  font-weight: 800;
  padding: 0;
}

.course-hero {
  display: grid;
  grid-template-columns: minmax(360px, 520px) 1fr;
  gap: 42px;
  align-items: center;
  max-width: 1410px;
  padding: 18px 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.course-hero > img {
  width: 100%;
  aspect-ratio: 16 / 9.7;
  border-radius: 8px;
  object-fit: cover;
}

.course-hero-copy h1 {
  margin: 0;
  color: var(--ink);
  font-size: clamp(1.9rem, 2.7vw, 3rem);
  line-height: 1.12;
}

.course-meta-line {
  color: var(--ink-soft);
  font-size: 1.05rem;
  font-weight: 700;
}

.course-hero-copy p {
  max-width: 860px;
  color: #3f527e;
  line-height: 1.6;
}

.summary-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  margin-top: 18px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.82);
}

.summary-bar > div {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 72px;
  padding: 12px 18px;
  border-right: 1px solid var(--line);
}

.summary-bar > div:last-child {
  border-right: 0;
}

.summary-bar small {
  display: block;
  color: var(--ink-soft);
  font-size: 0.78rem;
}

.summary-bar strong {
  display: block;
  margin-top: 4px;
  color: var(--ink);
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 18px;
}

.metric-icon,
.mini-symbol {
  position: relative;
  display: inline-grid;
  place-items: center;
  flex: 0 0 auto;
}

.metric-icon {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--blue-soft);
}

.mini-symbol {
  width: 18px;
  height: 18px;
}

.user-symbol::before {
  content: "";
  width: 9px;
  height: 9px;
  border: 2px solid var(--blue);
  border-radius: 50%;
}

.user-symbol::after {
  content: "";
  position: absolute;
  top: 25px;
  width: 18px;
  height: 10px;
  border: 2px solid var(--blue);
  border-bottom: 0;
  border-radius: 12px 12px 0 0;
}

.mini-symbol.user-symbol::after {
  top: 12px;
  width: 12px;
  height: 6px;
}

.mini-symbol.user-symbol::before {
  width: 5px;
  height: 5px;
}

.level-symbol::before {
  content: "";
  position: absolute;
  bottom: 12px;
  left: 13px;
  width: 5px;
  height: 9px;
  background: var(--blue);
  border-radius: 99px;
  box-shadow: 9px -5px 0 var(--blue), 18px -13px 0 var(--blue);
}

.clock-symbol::before {
  content: "";
  width: 24px;
  height: 24px;
  border: 3px solid var(--blue);
  border-radius: 50%;
}

.clock-symbol::after {
  content: "";
  position: absolute;
  width: 8px;
  height: 8px;
  border-left: 3px solid var(--blue);
  border-bottom: 3px solid var(--blue);
  transform: translate(2px, -2px) rotate(-45deg);
}

.progress-symbol::before {
  content: "";
  width: 26px;
  height: 26px;
  border: 4px solid #cddbf3;
  border-top-color: var(--blue);
  border-right-color: var(--blue);
  border-radius: 50%;
  transform: rotate(35deg);
}

.book-symbol::before {
  content: "";
  width: 18px;
  height: 15px;
  border: 2px solid var(--blue);
  border-radius: 3px;
  border-right-width: 1px;
}

.book-symbol::after {
  content: "";
  position: absolute;
  left: 8px;
  width: 2px;
  height: 16px;
  background: var(--blue);
}

.lesson-panel {
  max-width: 1640px;
  margin-top: 16px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow-soft);
}

.lesson-list {
  display: grid;
  gap: 8px;
}

.lesson-list.two-column {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  column-gap: 34px;
}

.lesson-row {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr) 78px 110px 34px;
  align-items: center;
  gap: 12px;
  min-height: 42px;
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: rgba(255, 255, 255, 0.92);
  text-align: left;
}

.lesson-row.active {
  border-color: var(--blue);
  background: linear-gradient(90deg, rgba(232, 243, 255, 0.95), rgba(255, 255, 255, 0.95));
  box-shadow: 0 0 0 1px rgba(5, 103, 255, 0.1);
}

.lesson-code {
  color: var(--blue);
  font-weight: 900;
  font-size: 0.83rem;
}

.lesson-title {
  min-width: 0;
  color: var(--ink);
  font-size: 0.9rem;
  font-weight: 700;
  line-height: 1.35;
}

.lesson-duration {
  color: var(--ink-soft);
  font-size: 0.86rem;
  font-weight: 700;
  text-align: right;
  white-space: nowrap;
}

.lesson-play {
  position: relative;
  width: 26px;
  height: 26px;
  border: 1px solid var(--blue);
  border-radius: 50%;
  background: #fff;
}

.lesson-play::before {
  content: "";
  position: absolute;
  left: 10px;
  top: 7px;
  border-top: 5px solid transparent;
  border-bottom: 5px solid transparent;
  border-left: 7px solid var(--blue);
}

.lesson-row.active .lesson-play {
  background: var(--blue);
}

.lesson-row.active .lesson-play::before {
  border-left-color: #fff;
}

.player-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  margin: 14px 0 20px;
}

.player-head h1 {
  margin: 0 0 14px;
  color: var(--ink);
  font-size: clamp(1.65rem, 2.4vw, 2.35rem);
  line-height: 1.15;
}

.player-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 18px 28px;
  color: var(--ink);
  font-weight: 700;
}

.player-meta span {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.player-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 490px;
  gap: 40px;
  align-items: start;
}

.video-column {
  min-width: 0;
}

.video-frame {
  position: relative;
  overflow: hidden;
  border: 8px solid #fff;
  border-radius: 8px;
  background: #06112e;
  box-shadow: var(--shadow);
}

.video-frame img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.video-play-button {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 78px;
  height: 78px;
  border-radius: 50%;
  background: rgba(5, 103, 255, 0.88);
  box-shadow: 0 16px 42px rgba(0, 0, 0, 0.25);
  transform: translate(-50%, -50%);
}

.video-play-button::before {
  content: "";
  margin-left: 5px;
  border-top: 16px solid transparent;
  border-bottom: 16px solid transparent;
  border-left: 24px solid #fff;
}

.video-frame.playing .video-play-button::before {
  width: 20px;
  height: 28px;
  border: 0;
  border-left: 7px solid #fff;
  border-right: 7px solid #fff;
}

.video-controls {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  display: grid;
  grid-template-columns: 22px 22px 22px auto 1fr auto 22px 22px;
  align-items: center;
  gap: 16px;
  min-height: 58px;
  padding: 0 24px;
  color: #fff;
  background: linear-gradient(180deg, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.86));
  font-weight: 700;
}

.control-play,
.control-next,
.control-volume,
.control-gear,
.control-fullscreen {
  position: relative;
  width: 22px;
  height: 22px;
}

.control-play::before {
  content: "";
  position: absolute;
  top: 4px;
  left: 6px;
  border-top: 7px solid transparent;
  border-bottom: 7px solid transparent;
  border-left: 10px solid #fff;
}

.control-next::before {
  content: "";
  position: absolute;
  top: 4px;
  left: 2px;
  border-top: 7px solid transparent;
  border-bottom: 7px solid transparent;
  border-left: 10px solid #fff;
  box-shadow: 7px 0 0 -3px #fff;
}

.control-volume::before {
  content: "";
  position: absolute;
  top: 6px;
  left: 2px;
  width: 8px;
  height: 10px;
  background: #fff;
  clip-path: polygon(0 28%, 42% 28%, 100% 0, 100% 100%, 42% 72%, 0 72%);
}

.control-volume::after {
  content: "";
  position: absolute;
  top: 5px;
  left: 12px;
  width: 7px;
  height: 12px;
  border-right: 2px solid #fff;
  border-radius: 50%;
}

.video-track {
  display: block;
  height: 6px;
  overflow: hidden;
  border-radius: 99px;
  background: rgba(255, 255, 255, 0.34);
}

.video-track span {
  display: block;
  width: 0;
  height: 100%;
  background: var(--blue);
}

.control-pill {
  display: inline-grid;
  place-items: center;
  width: 28px;
  height: 22px;
  border: 2px solid #fff;
  border-radius: 4px;
  font-size: 0.72rem;
}

.control-gear::before {
  content: "";
  position: absolute;
  inset: 3px;
  border: 3px dotted #fff;
  border-radius: 50%;
}

.control-fullscreen::before {
  content: "";
  position: absolute;
  inset: 3px;
  border: 2px solid #fff;
  border-top-color: transparent;
  border-left-color: transparent;
}

.control-fullscreen::after {
  content: "";
  position: absolute;
  inset: 3px;
  border: 2px solid #fff;
  border-bottom-color: transparent;
  border-right-color: transparent;
}

.lesson-actions {
  display: grid;
  grid-template-columns: 1fr 1.2fr 1fr;
  gap: 22px;
  margin-top: 26px;
  padding: 18px 36px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.9);
}

.chapter-panel {
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.chapter-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line);
}

.chapter-heading span {
  color: var(--ink-soft);
  font-weight: 800;
}

.chapter-list {
  display: grid;
}

.chapter-row {
  display: grid;
  grid-template-columns: 28px 72px minmax(0, 1fr) 60px 26px;
  align-items: center;
  gap: 12px;
  min-height: 58px;
  padding: 9px 0;
  border-bottom: 1px solid var(--line);
  text-align: left;
}

.chapter-row:last-child {
  border-bottom: 0;
}

.chapter-row.active {
  padding: 9px 10px;
  border: 1px solid var(--blue);
  border-radius: 7px;
  background: var(--blue-soft);
}

.chapter-number {
  color: var(--blue);
  font-size: 0.82rem;
  font-weight: 900;
}

.chapter-title {
  min-width: 0;
  color: var(--ink);
  font-size: 0.86rem;
  font-weight: 800;
  line-height: 1.35;
}

.chapter-time {
  color: var(--ink-soft);
  font-size: 0.82rem;
  font-weight: 800;
}

.chapter-status {
  position: relative;
  width: 22px;
  height: 22px;
  border: 1px solid #94a6c8;
  border-radius: 50%;
}

.chapter-status.play::before {
  content: "";
  position: absolute;
  top: 6px;
  left: 8px;
  border-top: 5px solid transparent;
  border-bottom: 5px solid transparent;
  border-left: 7px solid #6c7b9c;
}

.chapter-status.done {
  border-color: #27bc64;
}

.chapter-status.done::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 3px;
  width: 7px;
  height: 12px;
  border-right: 2px solid #27bc64;
  border-bottom: 2px solid #27bc64;
  transform: rotate(42deg);
}

.chapter-status.lock::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  width: 9px;
  height: 8px;
  background: #7181a2;
  border-radius: 2px;
}

.chapter-status.lock::after {
  content: "";
  position: absolute;
  left: 7px;
  top: 3px;
  width: 7px;
  height: 8px;
  border: 2px solid #7181a2;
  border-bottom: 0;
  border-radius: 7px 7px 0 0;
}

.learning-dashboard,
.admin-metrics {
  display: grid;
  grid-template-columns: repeat(4, minmax(180px, 1fr));
  gap: 18px;
  margin-bottom: 26px;
}

.metric-card {
  min-height: 126px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow-soft);
}

.metric-card small {
  display: block;
  color: var(--ink-soft);
  font-weight: 800;
}

.metric-card strong {
  display: block;
  margin-top: 8px;
  color: var(--ink);
  font-size: 2.1rem;
  line-height: 1;
}

.metric-card span {
  display: block;
  margin-top: 10px;
  color: var(--muted);
  font-size: 0.88rem;
}

.resource-list,
.announcement-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(240px, 1fr));
  gap: 18px;
}

.resource-item,
.announcement-item {
  min-height: 155px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow-soft);
}

.resource-item h3,
.announcement-item h3 {
  margin: 0 0 12px;
  font-size: 1.15rem;
}

.resource-item p,
.announcement-item p {
  margin: 0;
  color: var(--ink-soft);
  line-height: 1.55;
}

.resource-meta,
.announcement-date {
  display: inline-flex;
  margin-top: 16px;
  color: var(--blue);
  font-weight: 800;
}

.admin-section {
  padding-top: 38px;
}

.admin-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(360px, 0.8fr);
  gap: 22px;
  margin-bottom: 22px;
}

.admin-panel {
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow-soft);
}

.full-width-panel {
  margin-top: 22px;
}

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

.admin-form {
  display: grid;
  gap: 16px;
}

.compact-form {
  grid-template-columns: repeat(3, minmax(0, 1fr)) auto;
  align-items: end;
}

.admin-form label,
.auth-form label {
  display: grid;
  gap: 7px;
  color: var(--ink);
  font-weight: 800;
}

.admin-form label span,
.auth-form label span {
  font-size: 0.88rem;
}

.admin-form input,
.admin-form textarea,
.admin-form select,
.auth-form input {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--ink);
  background: #fff;
  padding: 10px 12px;
  outline: none;
}

.admin-form textarea {
  resize: vertical;
}

.admin-form input:focus,
.admin-form textarea:focus,
.admin-form select:focus,
.auth-form input:focus {
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(5, 103, 255, 0.12);
}

.file-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 620px;
}

th,
td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
  color: var(--ink);
  text-align: left;
  white-space: nowrap;
}

th {
  color: var(--ink-soft);
  background: #f7fbff;
  font-size: 0.82rem;
  text-transform: uppercase;
}

tr:last-child td {
  border-bottom: 0;
}

.table-progress {
  display: grid;
  grid-template-columns: minmax(100px, 1fr) 46px;
  align-items: center;
  gap: 12px;
}

.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: grid;
  place-items: center;
  padding: 24px;
  background: rgba(3, 14, 53, 0.45);
  backdrop-filter: blur(6px);
}

.auth-card {
  position: relative;
  width: min(520px, 100%);
  max-height: calc(100vh - 48px);
  overflow-y: auto;
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  box-shadow: 0 28px 70px rgba(3, 14, 53, 0.28);
}

.close-button {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 32px;
  height: 32px;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: #fff;
}

.close-button::before,
.close-button::after {
  content: "";
  position: absolute;
  width: 15px;
  height: 2px;
  background: var(--ink);
}

.close-button::before {
  transform: rotate(45deg);
}

.close-button::after {
  transform: rotate(-45deg);
}

.auth-heading {
  display: grid;
  grid-template-columns: 150px 1fr;
  gap: 16px;
  align-items: center;
  padding-right: 28px;
}

.auth-heading img {
  width: 150px;
  height: 56px;
  object-fit: contain;
  object-position: left center;
}

.auth-heading h2 {
  margin: 0;
  color: var(--ink);
  font-size: 1.45rem;
}

.auth-heading p {
  margin: 6px 0 0;
  color: var(--ink-soft);
  line-height: 1.45;
}

.auth-tabs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin: 24px 0 18px;
  padding: 5px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f6f9ff;
}

.auth-tabs button {
  min-height: 40px;
  border: 0;
  border-radius: 6px;
  color: var(--ink-soft);
  background: transparent;
  font-weight: 900;
}

.auth-tabs button.active {
  color: var(--blue);
  background: #fff;
  box-shadow: 0 6px 14px rgba(38, 85, 150, 0.1);
}

.auth-form {
  display: grid;
  gap: 14px;
}

.helper-line {
  margin: 0;
  color: var(--ink-soft);
  font-size: 0.88rem;
  line-height: 1.45;
}

.form-error {
  min-height: 20px;
  margin: 0;
  color: var(--red);
  font-weight: 800;
}

.toast {
  position: fixed;
  right: 26px;
  bottom: 26px;
  z-index: 80;
  max-width: 360px;
  padding: 14px 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--ink);
  background: #fff;
  box-shadow: var(--shadow);
  font-weight: 800;
}

@media (max-width: 1360px) {
  .topbar {
    padding: 0 28px;
    gap: 20px;
  }

  .brand {
    min-width: 220px;
  }

  .brand-logo {
    width: 210px;
  }

  .main-nav {
    gap: 18px;
  }

  .category-strip,
  .course-grid {
    grid-template-columns: repeat(3, minmax(220px, 1fr));
  }

  .course-grid.wide {
    grid-template-columns: repeat(3, minmax(220px, 1fr));
  }

  .player-layout {
    grid-template-columns: minmax(0, 1fr) 420px;
    gap: 24px;
  }

  .lesson-list.two-column {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 1080px) {
  .topbar {
    height: auto;
    flex-wrap: wrap;
    padding: 14px 24px;
  }

  .brand {
    min-width: 0;
  }

  .main-nav {
    order: 3;
    width: 100%;
    justify-content: flex-start;
    overflow-x: auto;
  }

  .nav-link {
    height: 44px;
    padding-top: 0;
  }

  .user-tools {
    min-width: 0;
  }

  .view {
    min-height: calc(100vh - 130px);
  }

  .hero-section,
  .content-section,
  .detail-container,
  .player-container {
    padding-left: 28px;
    padding-right: 28px;
  }

  .category-strip {
    grid-template-columns: repeat(2, minmax(220px, 1fr));
    padding-left: 28px;
    padding-right: 28px;
  }

  .course-hero,
  .player-layout,
  .admin-grid {
    grid-template-columns: 1fr;
  }

  .chapter-panel {
    order: -1;
  }

  .summary-bar,
  .learning-dashboard,
  .admin-metrics,
  .resource-list,
  .announcement-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .compact-form,
  .file-row {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  .topbar {
    align-items: flex-start;
  }

  .brand-logo {
    width: 180px;
    height: 56px;
  }

  .user-tools {
    gap: 8px;
  }

  .profile-button {
    min-width: 0;
  }

  .hero-section {
    min-height: 260px;
    padding-top: 38px;
  }

  .hero-copy h1 {
    font-size: 2.2rem;
  }

  .category-strip,
  .course-grid,
  .course-grid.wide,
  .summary-bar,
  .learning-dashboard,
  .admin-metrics,
  .resource-list,
  .announcement-list {
    grid-template-columns: 1fr;
  }

  .category-card {
    grid-template-columns: 64px 1fr 18px;
    min-height: 104px;
    padding: 14px;
  }

  .category-icon {
    width: 64px;
    height: 64px;
  }

  .section-heading,
  .panel-heading {
    align-items: flex-start;
    flex-direction: column;
  }

  .course-hero {
    padding: 14px;
    gap: 22px;
  }

  .summary-bar > div {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .summary-bar > div:last-child {
    border-bottom: 0;
  }

  .lesson-row {
    grid-template-columns: 78px minmax(0, 1fr) 34px;
    min-height: 58px;
  }

  .lesson-row .lesson-duration,
  .lesson-row .status-pill {
    display: none;
  }

  .player-meta {
    gap: 12px;
  }

  .video-controls {
    grid-template-columns: 22px auto 1fr auto;
  }

  .control-next,
  .control-volume,
  .control-gear,
  .control-fullscreen {
    display: none;
  }

  .lesson-actions {
    grid-template-columns: 1fr;
    padding: 14px;
  }

  .chapter-row {
    grid-template-columns: 28px 64px minmax(0, 1fr) 26px;
  }

  .chapter-time {
    display: none;
  }

  .auth-heading {
    grid-template-columns: 1fr;
  }
}