/*
    ========================================================
    DESIGN SYSTEM
    Đồng bộ homepage SEO TRẮNG
    ========================================================
    */

    :root {
      --st-bg: #f8fafc;
      --st-white: #ffffff;
      --st-soft: #f1f5f9;

      --st-dark: #0f172a;
      --st-text: #334155;
      --st-muted: #64748b;

      --st-blue: #1d4ed8;
      --st-blue-dark: #1e40af;
      --st-blue-soft: #eff6ff;

      --st-orange: #e87924;
      --st-orange-dark: #c9671e;
      --st-orange-soft: #fff7ed;

      --st-green-soft: #f0fdf4;
      --st-green: #15803d;

      --st-border: #e2e8f0;

      --st-radius-sm: 8px;
      --st-radius-md: 12px;
      --st-radius-lg: 20px;

      --st-shadow:
        0 1px 2px rgba(15, 23, 42, .03),
        0 8px 28px rgba(15, 23, 42, .06);

      --st-max: 1160px;
    }


    * {
      box-sizing: border-box;
    }


    html {
      scroll-behavior: smooth;
    }


    body {
      margin: 0;
      background: var(--st-bg);
      color: var(--st-text);

      font-family:
        Inter,
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        Roboto,
        Helvetica,
        Arial,
        sans-serif;

      line-height: 1.7;

      -webkit-font-smoothing: antialiased;
    }


    a {
      color: inherit;
    }


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


    button:focus-visible,
    a:focus-visible,
    input:focus-visible,
    textarea:focus-visible,
    select:focus-visible {
      outline: 3px solid rgba(29, 78, 216, .25);
      outline-offset: 3px;
    }


    .st-container {
      width: min(calc(100% - 40px), var(--st-max));
      margin-inline: auto;
    }


    .st-section {
      padding: 88px 0;
    }


    .st-section-white {
      background: var(--st-white);
      border-top: 1px solid var(--st-border);
      border-bottom: 1px solid var(--st-border);
    }


    .st-section-blue {
      background: var(--st-blue-soft);
      border-top: 1px solid #dbeafe;
      border-bottom: 1px solid #dbeafe;
    }


    /*
    ========================================================
    TYPOGRAPHY
    ========================================================
    */

    .st-eyebrow {
      display: inline-flex;
      align-items: center;
      gap: 8px;

      padding: 7px 13px;
      margin-bottom: 18px;

      border: 1px solid #bfdbfe;
      border-radius: 999px;

      background: var(--st-blue-soft);

      color: var(--st-blue-dark);

      font-size: 12px;
      font-weight: 800;

      letter-spacing: .06em;
      text-transform: uppercase;
    }


    .st-section-head {
      max-width: 790px;
      margin: 0 auto 48px;
      text-align: center;
    }


    .st-section-head h2 {
      margin: 0 0 12px;

      color: var(--st-dark);

      font-size: clamp(28px, 4vw, 40px);
      line-height: 1.25;

      letter-spacing: -.025em;
    }


    .st-section-head p {
      margin: 0;

      color: var(--st-muted);

      font-size: 16px;
    }


    /*
    ========================================================
    BUTTONS
    ========================================================
    */

    .st-btn {
      display: inline-flex;

      align-items: center;
      justify-content: center;

      gap: 8px;

      min-height: 48px;

      padding: 12px 22px;

      border: 1px solid transparent;
      border-radius: var(--st-radius-sm);

      cursor: pointer;

      font-size: 14px;
      font-weight: 750;

      text-decoration: none;

      transition:
        transform .2s ease,
        background .2s ease,
        border-color .2s ease;
    }


    .st-btn:hover {
      transform: translateY(-2px);
    }


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


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


    .st-btn-orange {
      background: var(--st-orange);
      color: #fff;
    }


    .st-btn-orange:hover {
      background: var(--st-orange-dark);
    }


    .st-btn-outline {
      background: #fff;
      color: var(--st-dark);

      border-color: var(--st-border);
    }


    .st-btn-outline:hover {
      border-color: #94a3b8;
    }


    /*
    ========================================================
    BREADCRUMB
    ========================================================
    */

    .st-breadcrumb {
      padding: 18px 0;

      background: #fff;

      border-bottom: 1px solid var(--st-border);

      font-size: 13px;
      color: var(--st-muted);
    }


    .st-breadcrumb ol {
      display: flex;

      gap: 8px;

      margin: 0;
      padding: 0;

      list-style: none;
    }


    .st-breadcrumb a {
      text-decoration: none;
    }


    .st-breadcrumb a:hover {
      color: var(--st-blue);
    }


    /*
    ========================================================
    HERO
    ========================================================
    */

    .st-hero {
      overflow: hidden;

      padding: 92px 0;

      background:
        radial-gradient(
          circle at 88% 16%,
          rgba(29,78,216,.10),
          transparent 28%
        ),
        radial-gradient(
          circle at 10% 85%,
          rgba(232,121,36,.07),
          transparent 26%
        ),
        #fff;
    }


    .st-hero-grid {
      display: grid;

      grid-template-columns:
        minmax(0, 1.08fr)
        minmax(330px, .92fr);

      gap: 62px;

      align-items: center;
    }


    .st-hero h1 {
      max-width: 760px;

      margin: 0 0 22px;

      color: var(--st-dark);

      font-size: clamp(38px, 6vw, 61px);

      line-height: 1.1;

      letter-spacing: -.045em;
    }


    .st-hero h1 span {
      color: var(--st-blue);
    }


    .st-hero-lead {
      max-width: 720px;

      margin: 0;

      color: var(--st-muted);

      font-size: 18px;
    }


    .st-hero-actions {
      display: flex;

      flex-wrap: wrap;

      gap: 12px;

      margin-top: 30px;
    }


    .st-small-note {
      max-width: 690px;

      margin-top: 28px;
      padding-top: 22px;

      border-top: 1px solid var(--st-border);

      color: var(--st-muted);

      font-size: 13px;
    }


    /*
    ========================================================
    HERO WORKSPACE MOCKUP
    Không dùng stock photo giả "lớp học".
    Sau này có thể thay bằng screenshot thật.
    ========================================================
    */

    .st-workspace {
      overflow: hidden;

      border: 1px solid #dbeafe;
      border-radius: var(--st-radius-lg);

      background: #fff;

      box-shadow:
        0 24px 60px rgba(15,23,42,.12);
    }


    .st-workspace-top {
      display: flex;

      gap: 6px;

      padding: 13px 16px;

      background: #f8fafc;

      border-bottom: 1px solid var(--st-border);
    }


    .st-dot {
      width: 9px;
      height: 9px;

      border-radius: 50%;

      background: #cbd5e1;
    }


    .st-workspace-body {
      padding: 26px;
    }


    .st-workspace-label {
      margin-bottom: 8px;

      color: var(--st-blue);

      font-size: 11px;
      font-weight: 850;

      text-transform: uppercase;
      letter-spacing: .08em;
    }


    .st-workspace-title {
      margin-bottom: 22px;

      color: var(--st-dark);

      font-size: 19px;
      font-weight: 800;
    }


    .st-work-line {
      display: grid;

      grid-template-columns: 28px 1fr;

      gap: 12px;

      align-items: center;

      padding: 13px 0;

      border-top: 1px solid var(--st-border);
    }


    .st-work-number {
      display: flex;

      align-items: center;
      justify-content: center;

      width: 27px;
      height: 27px;

      border-radius: 7px;

      background: var(--st-blue-soft);

      color: var(--st-blue);

      font-size: 11px;
      font-weight: 850;
    }


    .st-work-line strong {
      display: block;

      color: var(--st-dark);

      font-size: 13.5px;
    }


    .st-work-line small {
      color: var(--st-muted);

      font-size: 12px;
    }


    /*
    ========================================================
    FIT / NOT FIT
    ========================================================
    */

    .st-fit-grid {
      display: grid;

      grid-template-columns: 1fr 1fr;

      gap: 22px;
    }


    .st-fit-card {
      padding: 32px;

      border: 1px solid var(--st-border);
      border-radius: var(--st-radius-lg);

      background: #fff;

      box-shadow: var(--st-shadow);
    }


    .st-fit-card.good {
      border-color: #bbf7d0;
    }


    .st-fit-card.bad {
      border-color: #fed7aa;
    }


    .st-fit-card h3 {
      margin: 0 0 20px;

      color: var(--st-dark);

      font-size: 22px;
    }


    .st-list {
      margin: 0;
      padding: 0;

      list-style: none;
    }


    .st-list li {
      position: relative;

      margin-bottom: 15px;
      padding-left: 30px;

      color: var(--st-text);

      font-size: 14.5px;
    }


    .st-list li:last-child {
      margin-bottom: 0;
    }


    .st-fit-card.good li::before {
      content: "✓";

      position: absolute;
      left: 0;

      color: var(--st-green);

      font-weight: 900;
    }


    .st-fit-card.bad li::before {
      content: "—";

      position: absolute;
      left: 0;

      color: var(--st-orange);

      font-weight: 900;
    }


    /*
    ========================================================
    CURRICULUM / CHECKLIST
    ========================================================
    */

    .st-checklist-wrap {
      max-width: 920px;

      margin: auto;
    }


    .st-progress {
      display: grid;

      grid-template-columns: auto 1fr auto;

      gap: 16px;

      align-items: center;

      padding: 17px 20px;
      margin-bottom: 18px;

      border: 1px solid #dbeafe;
      border-radius: var(--st-radius-md);

      background: #fff;

      box-shadow: var(--st-shadow);
    }


    .st-progress-label {
      color: var(--st-dark);

      font-size: 13px;
      font-weight: 750;
    }


    .st-progress-track {
      overflow: hidden;

      height: 9px;

      border-radius: 999px;

      background: #dbeafe;
    }


    .st-progress-fill {
      width: 0%;
      height: 100%;

      border-radius: inherit;

      background: var(--st-orange);

      transition: width .25s ease;
    }


    .st-progress-value {
      min-width: 38px;

      color: var(--st-orange);

      font-size: 13px;
      font-weight: 850;

      text-align: right;
    }


    .st-module {
      margin-bottom: 16px;

      padding: 28px;

      border: 1px solid var(--st-border);
      border-radius: var(--st-radius-lg);

      background: #fff;

      box-shadow: var(--st-shadow);
    }


    .st-module:last-child {
      margin-bottom: 0;
    }


    .st-module-top {
      margin-bottom: 18px;
    }


    .st-module-number {
      display: block;

      margin-bottom: 6px;

      color: var(--st-blue);

      font-size: 11px;
      font-weight: 850;

      letter-spacing: .07em;
      text-transform: uppercase;
    }


    .st-module h3 {
      margin: 0;

      color: var(--st-dark);

      font-size: 20px;
    }


    .st-task {
      display: flex;

      gap: 12px;

      align-items: flex-start;

      margin-bottom: 8px;
      padding: 11px 13px;

      border: 1px solid var(--st-border);
      border-radius: 8px;

      background: #f8fafc;

      cursor: pointer;
    }


    .st-task:last-child {
      margin-bottom: 0;
    }


    .st-task:hover {
      border-color: #bfdbfe;

      background: var(--st-blue-soft);
    }


    .st-task input {
      flex: 0 0 auto;

      width: 17px;
      height: 17px;

      margin-top: 4px;

      accent-color: var(--st-blue);
    }


    .st-task span {
      color: var(--st-text);

      font-size: 14px;
    }


    .st-task.is-done span {
      color: var(--st-muted);

      text-decoration: line-through;
    }


    .st-checklist-note {
      margin: 16px 0 0;

      color: var(--st-muted);

      font-size: 12.5px;

      text-align: center;
    }


    /*
    ========================================================
    LEARNING PROCESS
    ========================================================
    */

    .st-process-grid {
      display: grid;

      grid-template-columns: repeat(4, 1fr);

      gap: 18px;
    }


    .st-process-card {
      padding: 26px;

      border: 1px solid var(--st-border);
      border-radius: var(--st-radius-lg);

      background: #fff;

      box-shadow: var(--st-shadow);
    }


    .st-process-no {
      width: 38px;
      height: 38px;

      display: flex;

      align-items: center;
      justify-content: center;

      margin-bottom: 20px;

      border-radius: 10px;

      background: var(--st-dark);

      color: #fff;

      font-size: 12px;
      font-weight: 850;
    }


    .st-process-card h3 {
      margin: 0 0 9px;

      color: var(--st-dark);

      font-size: 17px;
    }


    .st-process-card p {
      margin: 0;

      color: var(--st-muted);

      font-size: 13.5px;
    }


    /*
    ========================================================
    LEARNING PRINCIPLE
    ========================================================
    */

    .st-dark-block {
      overflow: hidden;

      border-radius: var(--st-radius-lg);

      background: var(--st-dark);

      color: #fff;
    }


    .st-dark-intro {
      max-width: 770px;

      padding: 52px 52px 38px;
    }


    .st-dark-intro small {
      color: #93c5fd;

      font-weight: 850;

      letter-spacing: .07em;
      text-transform: uppercase;
    }


    .st-dark-intro h2 {
      margin: 10px 0 14px;

      font-size: clamp(28px, 4vw, 40px);

      line-height: 1.25;
    }


    .st-dark-intro p {
      margin: 0;

      color: #94a3b8;
    }


    .st-dark-grid {
      display: grid;

      grid-template-columns: repeat(2, 1fr);

      border-top: 1px solid rgba(255,255,255,.08);
    }


    .st-dark-item {
      padding: 30px 52px;

      border-bottom: 1px solid rgba(255,255,255,.08);
    }


    .st-dark-item:nth-child(odd) {
      border-right: 1px solid rgba(255,255,255,.08);
    }


    .st-dark-item strong {
      display: block;

      margin-bottom: 7px;

      color: #fff;
    }


    .st-dark-item p {
      margin: 0;

      color: #94a3b8;

      font-size: 14px;
    }


    /*
    ========================================================
    COURSE DETAILS
    ========================================================
    */

    .st-detail-grid {
      display: grid;

      grid-template-columns: repeat(3, 1fr);

      gap: 18px;
    }


    .st-detail-card {
      padding: 26px;

      border: 1px solid var(--st-border);
      border-radius: var(--st-radius-lg);

      background: #fff;

      text-align: center;

      box-shadow: var(--st-shadow);
    }


    .st-detail-icon {
      margin-bottom: 12px;

      font-size: 26px;
    }


    .st-detail-card strong {
      display: block;

      margin-bottom: 7px;

      color: var(--st-dark);
    }


    .st-detail-card span {
      color: var(--st-muted);

      font-size: 13.5px;
    }


    /*
    ========================================================
    HONEST CTA
    ========================================================
    */

    .st-conversation {
      display: grid;

      grid-template-columns: 1.05fr .95fr;

      gap: 46px;

      align-items: center;

      padding: 46px;

      border: 1px solid #fed7aa;
      border-radius: var(--st-radius-lg);

      background: var(--st-orange-soft);
    }


    .st-conversation h2 {
      margin: 0 0 14px;

      color: var(--st-dark);

      font-size: 32px;
      line-height: 1.3;
    }


    .st-conversation p {
      margin: 0;

      color: var(--st-muted);
    }


    .st-conversation-note {
      padding: 24px;

      border: 1px solid #fed7aa;
      border-radius: var(--st-radius-md);

      background: #fff;
    }


    .st-conversation-note strong {
      display: block;

      margin-bottom: 8px;

      color: var(--st-dark);
    }


    .st-conversation-note p {
      font-size: 13.5px;
    }


    /*
    ========================================================
    FAQ
    ========================================================
    */

    .st-faq-wrap {
      max-width: 850px;

      margin: auto;
    }


    .st-faq-item {
      overflow: hidden;

      margin-bottom: 12px;

      border: 1px solid var(--st-border);
      border-radius: var(--st-radius-md);

      background: #fff;
    }


    .st-faq-button {
      display: flex;

      width: 100%;

      justify-content: space-between;
      align-items: center;

      gap: 20px;

      padding: 20px 22px;

      border: 0;

      background: #fff;

      color: var(--st-dark);

      cursor: pointer;

      font-weight: 750;

      text-align: left;
    }


    .st-faq-button:hover {
      background: #f8fafc;
    }


    .st-faq-icon {
      flex: 0 0 auto;

      font-size: 20px;

      transition: transform .2s ease;
    }


    .st-faq-answer {
      display: none;

      padding: 0 22px 22px;

      color: var(--st-muted);

      font-size: 14.5px;
    }


    .st-faq-item.is-open .st-faq-answer {
      display: block;
    }


    .st-faq-item.is-open .st-faq-icon {
      transform: rotate(45deg);
    }


    /*
    ========================================================
    FORM
    ========================================================
    */

    .st-contact-grid {
      display: grid;

      grid-template-columns: .85fr 1.15fr;

      max-width: 1000px;

      margin: auto;

      overflow: hidden;

      border: 1px solid var(--st-border);
      border-radius: var(--st-radius-lg);

      background: #fff;

      box-shadow: var(--st-shadow);
    }


    .st-contact-info {
      padding: 40px;

      background: var(--st-dark);

      color: #fff;
    }


    .st-contact-info h2 {
      margin: 0 0 12px;

      font-size: 30px;
    }


    .st-contact-info > p {
      color: #94a3b8;
    }


    .st-contact-row {
      margin-top: 26px;
    }


    .st-contact-row div {
      margin-bottom: 17px;

      color: #cbd5e1;

      font-size: 13.5px;
    }


    .st-contact-row strong {
      display: block;

      color: #fff;
    }


    .st-contact-form {
      padding: 40px;
    }


    .st-form-row {
      display: grid;

      grid-template-columns: 1fr 1fr;

      gap: 16px;
    }


    .st-field {
      margin-bottom: 16px;
    }


    .st-field label {
      display: block;

      margin-bottom: 6px;

      color: var(--st-dark);

      font-size: 13px;
      font-weight: 700;
    }


    .st-input,
    .st-select,
    .st-textarea {
      width: 100%;

      padding: 12px 14px;

      border: 1px solid var(--st-border);
      border-radius: 8px;

      background: #fff;

      color: var(--st-text);

      outline: none;
    }


    .st-input:focus,
    .st-select:focus,
    .st-textarea:focus {
      border-color: #60a5fa;

      box-shadow:
        0 0 0 3px rgba(59,130,246,.10);
    }


    .st-form-status {
      display: none;

      margin-top: 14px;
      padding: 12px 14px;

      border-radius: 8px;

      font-size: 13px;
    }


    .st-form-status.error {
      display: block;

      border: 1px solid #fed7aa;

      background: var(--st-orange-soft);

      color: #9a3412;
    }


    .st-form-status.success {
      display: block;

      border: 1px solid #bbf7d0;

      background: #f0fdf4;

      color: #166534;
    }


    /*
    ========================================================
    FINAL DISCLAIMER
    ========================================================
    */

    .st-seo-note {
      max-width: 800px;

      margin: 32px auto 0;

      color: var(--st-muted);

      font-size: 12.5px;

      text-align: center;
    }


    /*
    ========================================================
    RESPONSIVE
    ========================================================
    */

    @media (max-width: 960px) {

      .st-hero-grid,
      .st-conversation,
      .st-contact-grid {
        grid-template-columns: 1fr;
      }


      .st-process-grid {
        grid-template-columns: repeat(2, 1fr);
      }


      .st-detail-grid {
        grid-template-columns: 1fr 1fr;
      }

    }


    @media (max-width: 720px) {

      .st-section {
        padding: 64px 0;
      }


      .st-container {
        width: min(calc(100% - 30px), var(--st-max));
      }


      .st-hero {
        padding: 68px 0;
      }


      .st-hero h1 {
        font-size: 40px;
      }


      .st-fit-grid,
      .st-process-grid,
      .st-detail-grid,
      .st-dark-grid,
      .st-form-row {
        grid-template-columns: 1fr;
      }


      .st-dark-item:nth-child(odd) {
        border-right: 0;
      }


      .st-dark-intro {
        padding: 34px 26px 26px;
      }


      .st-dark-item {
        padding: 26px;
      }


      .st-progress {
        grid-template-columns: 1fr auto;
      }


      .st-progress-track {
        grid-column: 1 / -1;
        grid-row: 2;
      }


      .st-conversation,
      .st-contact-info,
      .st-contact-form {
        padding: 28px;
      }

    }