:root {
  --bg: #0f1118;
  --sidebar: #161924;
  --surface: #151a27;
  --surface-2: #121724;
  --line: #252c3f;
  --text: #dce3f7;
  --muted: #94a0bf;
  --accent: #6ea2ff;
  --accent-soft: rgba(110, 162, 255, 0.12);
}

[data-theme="light"] {
  --bg: #f2f5fb;
  --sidebar: #eaf0fb;
  --surface: #ffffff;
  --surface-2: #f8faff;
  --line: #d8dfef;
  --text: #131a2a;
  --muted: #5b6783;
  --accent: #2d66d8;
  --accent-soft: rgba(45, 102, 216, 0.1);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

a {
  color: inherit;
}

.layout {
  min-height: 100vh;
}

.sidebar {
  position: fixed;
  inset: 0 auto 0 0;
  width: 260px;
  background: linear-gradient(180deg, var(--sidebar), #141824);
  border-right: 1px solid var(--line);
  padding: 1.15rem 1rem 1rem;
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
}

.profile-box {
  text-align: left;
  padding: 0.2rem 0.2rem 0.8rem;
}

.profile-home-link {
  color: inherit;
  text-decoration: none;
  display: inline-block;
}

.profile-box img {
  width: 196px;
  height: 196px;
  border-radius: 50%;
  object-fit: cover;
  object-position: center 15%;
  border: 3px solid #8eb5ff;
  box-shadow: 0 0 0 5px rgba(110, 162, 255, 0.2);
}

.profile-box h1 {
  margin: 0.8rem 0 0.3rem;
  font-size: 1.58rem;
  line-height: 1.14;
  white-space: nowrap;
}

.profile-box p {
  margin: 0;
  color: var(--muted);
  font-size: 0.93rem;
}

.location {
  display: block;
  margin-top: 0.28rem;
  color: #8eb5ff;
  font-size: 0.88rem;
  font-weight: 600;
}

.side-nav {
  display: grid;
  gap: 0.35rem;
}

.side-nav a {
  text-decoration: none;
  color: var(--text);
  font-size: 0.91rem;
  padding: 0.62rem 0.78rem;
  border-radius: 10px;
  border: 1px solid transparent;
}

.side-nav a:hover {
  background: rgba(255, 255, 255, 0.03);
  border-color: #26314a;
}

.side-nav a.active {
  color: #dfe8ff;
  background: linear-gradient(180deg, #23304a, #1d263a);
  border-color: #365180;
  box-shadow: 0 8px 18px rgba(6, 12, 24, 0.35);
}

[data-theme="light"] .side-nav a.active {
  color: #183161;
  background: linear-gradient(180deg, #dce8ff, #ccdffc);
  border-color: #a2bee9;
}

.side-social {
  margin-top: auto;
  display: flex;
  gap: 0.52rem;
}

.side-social a {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: rgba(37, 49, 80, 0.8);
  border: 1px solid #2d3854;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #c6d4f3;
}

.side-social a:hover {
  background: #253150;
  border-color: #4f71b5;
}

[data-theme="light"] .side-social a {
  background: #ffffff;
  border-color: #c5d3f0;
  color: #2a4278;
}

.theme-toggle {
  position: fixed;
  top: 1rem;
  right: 1rem;
  width: 62px;
  height: 32px;
  border: 1px solid #40507a;
  background: #253152;
  border-radius: 999px;
  overflow: hidden;
  font-size: 0;
  padding: 0;
  cursor: pointer;
  z-index: 1200;
}

.theme-toggle::after {
  content: "🌙";
  position: absolute;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: #ffffff;
  top: 3px;
  left: 3px;
  transition: transform 180ms ease;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.35);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  line-height: 1;
}

[data-theme="light"] .theme-toggle::after {
  transform: translateX(30px);
  content: "☀️";
}

.theme-toggle:hover {
  border-color: #7b9de6;
}

[data-theme="light"] .theme-toggle {
  background: #9db8ef;
  border-color: #88a8e2;
}

.side-social svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
}

.content {
  margin-left: 260px;
  padding: 1.5rem 1.6rem 2rem;
  max-width: 1200px;
}

.page-head {
  margin-bottom: 1rem;
}

.page-head h2 {
  margin: 0;
  font-size: 1.85rem;
}

.page-head p {
  margin: 0.4rem 0 0;
  color: var(--muted);
}

.card,
.timeline-item,
.panel-card {
  background: linear-gradient(180deg, var(--surface), var(--surface-2));
  border: 1px solid var(--line);
  border-radius: 14px;
  position: relative;
  overflow: hidden;
  box-shadow: 0 14px 30px rgba(5, 10, 20, 0.34), 0 0 0 1px rgba(120, 170, 255, 0.08);
}

.card::before,
.timeline-item::before,
.panel-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(145deg, rgba(131, 177, 255, 0.18), rgba(131, 177, 255, 0) 40%);
  pointer-events: none;
}

.card::after,
.timeline-item::after,
.panel-card::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(
    125deg,
    rgba(142, 188, 255, 0.58),
    rgba(122, 108, 255, 0.26),
    rgba(142, 188, 255, 0.46)
  );
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
}

.card:hover,
.timeline-item:hover,
.panel-card:hover {
  box-shadow: 0 16px 34px rgba(6, 12, 24, 0.42), 0 0 24px rgba(98, 143, 229, 0.22);
}

.card {
  padding: 1rem 1.05rem;
}

.card h3,
.card h4 {
  margin: 0 0 0.55rem;
  color: var(--text);
}

.card p {
  margin: 0;
  color: #a4b0cf;
  line-height: 1.62;
}

.hero-card {
  margin-bottom: 1rem;
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.48rem;
  margin-top: 0.9rem;
}

.tag-row span {
  background: var(--accent-soft);
  border: 1px solid rgba(110, 162, 255, 0.45);
  color: var(--text);
  border-radius: 999px;
  padding: 0.28rem 0.62rem;
  font-size: 0.81rem;
}

.cards-grid {
  display: grid;
  gap: 0.85rem;
  margin-bottom: 1rem;
}

.cards-grid.one {
  grid-template-columns: 1fr;
}

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

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

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

.learning-courses {
  grid-template-columns: repeat(3, minmax(0, 1fr)) !important;
}

.section-title {
  margin: 0 0 0.7rem;
  font-size: 1.14rem;
  color: var(--text);
}

.card-list {
  margin-bottom: 1rem;
}

.timeline-item {
  padding: 0.9rem 1rem;
  display: grid;
  grid-template-columns: 130px 1fr;
  gap: 0.8rem;
  margin-bottom: 0.7rem;
}

.timeline-item h4 {
  margin: 0 0 0.45rem;
}

.timeline-item p {
  margin: 0;
  color: #a7b4d4;
  line-height: 1.58;
}

.year {
  color: #7aa3f2;
  font-weight: 700;
  font-size: 0.88rem;
}

.cert-badge-link {
  display: inline-block;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid #2f3850;
}

.cert-badge-link:hover {
  border-color: #5a7dc0;
  box-shadow: 0 10px 24px rgba(48, 82, 151, 0.35);
}

.cert-badge-image {
  width: 86px;
  height: 86px;
  object-fit: contain;
  display: block;
  background: #ffffff;
  padding: 0.2rem;
}

.timeline-item a,
.text-link {
  color: #8db4ff;
  text-decoration: none;
  font-weight: 600;
}

.timeline-item a:hover,
.text-link:hover {
  color: #a7c7ff;
}

.article-card,
.video-card,
.course-card {
  min-height: 165px;
}

.course-card {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.course-logo {
  width: min(210px, 94%);
  height: 110px;
  object-fit: contain;
  display: block;
  margin: 0.15rem 0 0.65rem;
  background: #ffffff;
  border: 1px solid #8ea2ce;
  border-radius: 12px;
  padding: 0.7rem;
}

.course-logo-link {
  display: inline-block;
  border-radius: 12px;
  overflow: hidden;
}

.certificates-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.85rem;
}

.cert-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 0.72rem;
}

.cert-card h4 {
  margin: 0.45rem 0 0;
  line-height: 1.35;
  font-size: 0.86rem;
}

[data-theme="light"] .sidebar {
  background: linear-gradient(180deg, #e9f0ff, #dfe7f8);
}

[data-theme="light"] .card,
[data-theme="light"] .timeline-item,
[data-theme="light"] .panel-card {
  box-shadow: 0 10px 22px rgba(44, 73, 130, 0.08), 0 0 0 1px rgba(80, 118, 199, 0.08);
}

.right-panel {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.8rem;
  margin-top: 0.25rem;
}

.panel-card {
  padding: 1rem;
}

.panel-card h3 {
  margin: 0 0 0.7rem;
  font-size: 1rem;
}

.panel-card ul {
  margin: 0;
  padding: 0 0 0 1rem;
}

.panel-card li {
  color: #9ca9ca;
  margin-bottom: 0.4rem;
}

.video-frame {
  width: 100%;
  border: 1px solid #2b334a;
  border-radius: 12px;
  overflow: hidden;
  margin-top: 0.4rem;
}

.video-frame iframe {
  width: 100%;
  aspect-ratio: 16 / 9;
  border: 0;
  display: block;
}

.contact-card h3 {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.contact-lines {
  display: grid;
  gap: 0.7rem;
  margin-bottom: 1rem;
  max-width: 620px;
  width: 100%;
  justify-items: stretch;
}

.contact-line {
  padding: 0.82rem 0.9rem;
  width: 100%;
}

.contact-line a {
  display: grid;
  grid-template-columns: 42px 92px minmax(0, 1fr);
  align-items: center;
  gap: 0.8rem;
}

.contact-line a span:last-child {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.contact-icon {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: rgba(110, 162, 255, 0.14);
  border: 1px solid rgba(110, 162, 255, 0.4);
  color: #bcd3ff;
}

.contact-icon svg {
  width: 20px;
  height: 20px;
  fill: currentColor;
}

.contact-form-card h3 {
  margin-bottom: 0.85rem;
}

.contact-form {
  display: grid;
  gap: 0.8rem;
}

.contact-form label {
  display: grid;
  gap: 0.35rem;
  color: var(--muted);
  font-size: 0.92rem;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  border: 1px solid #3a4668;
  background: rgba(10, 14, 24, 0.38);
  color: var(--text);
  border-radius: 10px;
  padding: 0.62rem 0.75rem;
  font: inherit;
}

[data-theme="light"] .contact-form input,
[data-theme="light"] .contact-form textarea {
  background: #ffffff;
  border-color: #c4d0ea;
}

.contact-form button {
  justify-self: start;
  border: 1px solid #4b73c3;
  background: linear-gradient(180deg, #5a88e8, #3f6fcc);
  color: #ffffff;
  border-radius: 10px;
  padding: 0.58rem 0.9rem;
  font-weight: 600;
  cursor: pointer;
}

.form-status {
  margin: 0.2rem 0 0;
  min-height: 1.2rem;
  font-size: 0.9rem;
  color: var(--muted);
}

.form-status.success {
  color: #66d896;
}

.form-status.error {
  color: #ff8f8f;
}

.course-browser {
  display: grid;
  gap: 1rem;
}

.course-browser-head {
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.course-choose-label {
  margin: 0;
  font-weight: 600;
  color: var(--text);
}

.course-choose {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.75rem;
}

.course-choose button {
  background: rgba(48, 70, 117, 0.15);
  border: 1px solid var(--line);
  color: var(--text);
  border-radius: 12px;
  padding: 0.55rem 0.75rem;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.55rem;
}

.course-choose button:hover {
  border-color: #5f86da;
}

.course-choose button.active {
  background: rgba(95, 134, 218, 0.25);
  border-color: #7b9de6;
}

.course-pill-icon {
  width: 26px;
  height: 26px;
  border-radius: 999px;
  overflow: hidden;
  flex-shrink: 0;
  background: #ffffff;
  border: 1px solid #dbe4f8;
}

.course-pill-icon img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}

.course-browser-head label {
  font-weight: 600;
  color: var(--text);
}

.course-select {
  width: min(360px, 100%);
  background: var(--card-bg);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.55rem 0.75rem;
  font: inherit;
}

.course-player-wrap {
  display: grid;
  gap: 0.85rem;
}

.course-player {
  width: 100%;
  max-height: 560px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: #000;
}

.course-player-meta h3 {
  margin: 0 0 0.4rem;
}

.course-player-meta p {
  margin: 0 0 0.5rem;
  color: var(--muted);
}

.course-lesson-list {
  margin: 0;
  padding-left: 1.25rem;
  display: grid;
  gap: 0.5rem;
  max-height: 420px;
  overflow: auto;
}

.course-lesson-list button {
  width: 100%;
  text-align: left;
  background: rgba(48, 70, 117, 0.2);
  border: 1px solid var(--line);
  color: var(--text);
  border-radius: 10px;
  padding: 0.5rem 0.65rem;
  cursor: pointer;
}

.course-lesson-list button:hover {
  border-color: #5f86da;
}

.course-lesson-list button.active {
  background: rgba(95, 134, 218, 0.25);
  border-color: #7b9de6;
}

@media (max-width: 1100px) {
  .cards-grid.four {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

@media (max-width: 900px) {
  .sidebar {
    position: static;
    width: 100%;
    border-right: none;
    border-bottom: 1px solid var(--line);
  }

  .content {
    margin-left: 0;
  }

  .cards-grid.two,
  .cards-grid.three,
  .cards-grid.four,
  .right-panel,
  .certificates-grid {
    grid-template-columns: 1fr;
  }

  .learning-courses {
    grid-template-columns: 1fr !important;
  }

  .course-choose {
    grid-template-columns: 1fr;
  }

  .contact-line a {
    grid-template-columns: 40px 1fr;
  }

  .contact-line a span:last-child {
    grid-column: 2;
  }
}

@media (max-width: 680px) {
  .content {
    padding: 1rem;
  }

  .timeline-item,
  .cert-item {
    grid-template-columns: 1fr;
  }
}