:root {
      --primary-950: #073f3a;
      --primary-900: #07534c;
      --primary-800: #0b6b61;
      --primary-700: #0f8175;
      --primary-500: #20a798;
      --primary-100: #dff5f1;
      --primary-50: #effaf8;
      --accent: #ff8d73;
      --text: #18312f;
      --text-muted: #667a77;
      --surface: rgba(255, 255, 255, .94);
      --surface-soft: #f7fbfa;
      --border: #dceae7;
      --danger-bg: #fff1ee;
      --danger-text: #a43d2e;
      --danger-border: #f4c6bc;
      --shadow: 0 28px 70px rgba(3, 57, 52, .22);
      --radius-xl: 28px;
      --radius-lg: 18px;
      --radius-md: 14px;
    }

    * {
      box-sizing: border-box;
    }

    html {
      min-height: 100%;
      background: var(--primary-900);
    }

    body {
      min-height: 100vh;
      margin: 0;
      font-family: 'Sarabun', sans-serif;
      color: var(--text);
      background:
        radial-gradient(circle at 10% 10%, rgba(255, 255, 255, .16), transparent 30%),
        radial-gradient(circle at 90% 85%, rgba(255, 141, 115, .18), transparent 28%),
        linear-gradient(135deg, var(--primary-950) 0%, var(--primary-800) 55%, var(--primary-500) 100%);
      overflow-x: hidden;
    }

    body::before,
    body::after {
      content: '';
      position: fixed;
      border-radius: 999px;
      filter: blur(2px);
      pointer-events: none;
      z-index: 0;
    }

    body::before {
      width: 320px;
      height: 320px;
      top: -130px;
      right: -90px;
      background: rgba(255, 255, 255, .08);
    }

    body::after {
      width: 240px;
      height: 240px;
      left: -90px;
      bottom: -100px;
      background: rgba(255, 141, 115, .13);
    }

    a,
    button {
      -webkit-tap-highlight-color: transparent;
    }

    .page-shell {
      position: relative;
      z-index: 1;
      min-height: 100vh;
      display: grid;
      grid-template-columns: minmax(0, 1.1fr) minmax(420px, .9fr);
      align-items: stretch;
    }

    .intro-panel {
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      padding: clamp(32px, 5vw, 72px);
      color: #fff;
    }

    .brand {
      display: inline-flex;
      align-items: center;
      gap: 12px;
      width: fit-content;
      font-family: 'Kanit', sans-serif;
      font-size: 15px;
      font-weight: 500;
      color: rgba(255, 255, 255, .9);
    }

    .brand-mark {
      display: grid;
      place-items: center;
      width: 42px;
      height: 42px;
      border-radius: 14px;
      background: rgba(255, 255, 255, .14);
      border: 1px solid rgba(255, 255, 255, .2);
      backdrop-filter: blur(10px);
      box-shadow: 0 12px 30px rgba(0, 0, 0, .12);
      font-size: 20px;
    }

    .intro-content {
      max-width: 680px;
      margin: 70px 0;
    }

    .eyebrow {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      margin-bottom: 20px;
      padding: 8px 13px;
      border: 1px solid rgba(255, 255, 255, .2);
      border-radius: 999px;
      background: rgba(255, 255, 255, .1);
      font-size: 13px;
      font-weight: 600;
      backdrop-filter: blur(10px);
    }

    .eyebrow-dot {
      width: 8px;
      height: 8px;
      border-radius: 50%;
      background: var(--accent);
      box-shadow: 0 0 0 5px rgba(255, 141, 115, .18);
    }

    .intro-content h1 {
      margin: 0;
      font-family: 'Kanit', sans-serif;
      font-size: clamp(40px, 5.2vw, 72px);
      line-height: 1.08;
      font-weight: 700;
      letter-spacing: -.03em;
      text-wrap: balance;
    }

    .intro-content p {
      max-width: 620px;
      margin: 24px 0 0;
      font-size: clamp(17px, 1.5vw, 21px);
      line-height: 1.8;
      color: rgba(255, 255, 255, .82);
    }

    .feature-list {
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 14px;
      margin-top: 36px;
    }

    .feature-item {
      padding: 16px;
      border-radius: 18px;
      border: 1px solid rgba(255, 255, 255, .16);
      background: rgba(255, 255, 255, .08);
      backdrop-filter: blur(10px);
    }

    .feature-item strong {
      display: block;
      margin-bottom: 4px;
      font-family: 'Kanit', sans-serif;
      font-size: 15px;
      font-weight: 600;
    }

    .feature-item span {
      font-size: 13px;
      line-height: 1.55;
      color: rgba(255, 255, 255, .72);
    }

    .intro-footer {
      font-size: 13px;
      color: rgba(255, 255, 255, .62);
    }

    .auth-panel {
      display: flex;
      align-items: center;
      justify-content: center;
      padding: clamp(20px, 4vw, 56px);
      background: rgba(248, 253, 252, .12);
      backdrop-filter: blur(18px);
      border-left: 1px solid rgba(255, 255, 255, .12);
    }

    .auth-card {
      width: 100%;
      max-width: 520px;
      padding: clamp(28px, 4vw, 48px);
      background: var(--surface);
      border: 1px solid rgba(255, 255, 255, .72);
      border-radius: var(--radius-xl);
      box-shadow: var(--shadow);
      backdrop-filter: blur(24px);
    }

    .mobile-brand {
      display: none;
      margin-bottom: 26px;
      color: var(--primary-900);
    }

    .back-home {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      min-height: 40px;
      margin-bottom: 28px;
      color: var(--primary-800);
      font-family: 'Kanit', sans-serif;
      font-size: 14px;
      font-weight: 500;
      text-decoration: none;
      transition: color .2s ease, transform .2s ease;
    }

    .back-home:hover {
      color: var(--primary-950);
      transform: translateX(-2px);
    }

    .auth-heading {
      margin-bottom: 30px;
    }

    .auth-heading h2 {
      margin: 0;
      font-family: 'Kanit', sans-serif;
      font-size: clamp(30px, 3vw, 40px);
      line-height: 1.2;
      font-weight: 700;
      letter-spacing: -.02em;
      color: var(--primary-950);
    }

    .auth-heading p {
      margin: 12px 0 0;
      font-size: 15px;
      line-height: 1.75;
      color: var(--text-muted);
    }

    .alert {
      display: flex;
      align-items: flex-start;
      gap: 10px;
      margin-bottom: 20px;
      padding: 14px 16px;
      border: 1px solid var(--danger-border);
      border-radius: var(--radius-md);
      background: var(--danger-bg);
      color: var(--danger-text);
      font-size: 14px;
      line-height: 1.6;
    }

    .alert-icon {
      flex: 0 0 auto;
      margin-top: 1px;
    }

    .login-box {
      padding: 22px;
      border: 1px solid var(--border);
      border-radius: var(--radius-lg);
      background: linear-gradient(180deg, #fff, var(--surface-soft));
    }

    .login-box-title {
      margin: 0 0 6px;
      font-family: 'Kanit', sans-serif;
      font-size: 16px;
      font-weight: 600;
      color: var(--primary-950);
    }

    .login-box-text {
      margin: 0 0 18px;
      font-size: 13.5px;
      line-height: 1.65;
      color: var(--text-muted);
    }

    .btn-thai-id {
      position: relative;
      width: 100%;
      min-height: 58px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 12px;
      padding: 14px 20px;
      border: 0;
      border-radius: 15px;
      background: linear-gradient(135deg, var(--primary-900), var(--primary-700));
      color: #fff;
      font-family: 'Kanit', sans-serif;
      font-size: 16px;
      font-weight: 600;
      text-decoration: none;
      box-shadow: 0 16px 30px rgba(11, 107, 97, .24);
      overflow: hidden;
      transition: transform .2s ease, box-shadow .2s ease, filter .2s ease;
    }

    .btn-thai-id::after {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(110deg, transparent 20%, rgba(255, 255, 255, .17) 48%, transparent 75%);
      transform: translateX(-120%);
      transition: transform .55s ease;
    }

    .btn-thai-id:hover {
      transform: translateY(-2px);
      box-shadow: 0 20px 36px rgba(11, 107, 97, .3);
      filter: saturate(1.08);
    }

    .btn-thai-id:hover::after {
      transform: translateX(120%);
    }

    .btn-thai-id:focus-visible,
    .back-home:focus-visible,
    .register-link:focus-visible {
      outline: 3px solid rgba(32, 167, 152, .28);
      outline-offset: 3px;
    }

    .thai-id-icon-wrap {
      display: grid;
      place-items: center;
      width: 34px;
      height: 34px;
      border-radius: 10px;
      background: #fff;
      box-shadow: 0 6px 14px rgba(0, 0, 0, .12);
      z-index: 1;
    }

    .thai-id-icon {
      width: 24px;
      height: 24px;
      object-fit: contain;
    }

    .btn-text {
      position: relative;
      z-index: 1;
    }

    .secure-note {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      margin-top: 14px;
      color: var(--text-muted);
      font-size: 12.5px;
    }

    .secure-note svg {
      width: 16px;
      height: 16px;
      color: var(--primary-700);
    }

    .divider {
      display: flex;
      align-items: center;
      gap: 14px;
      margin: 28px 0;
      color: #94a6a3;
      font-size: 12px;
    }

    .divider::before,
    .divider::after {
      content: '';
      flex: 1;
      height: 1px;
      background: var(--border);
    }

    .register-box {
      text-align: center;
    }

    .register-box p {
      margin: 0 0 12px;
      font-size: 14px;
      color: var(--text-muted);
    }

    .register-link {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      min-height: 46px;
      padding: 10px 18px;
      border: 1px solid var(--border);
      border-radius: 13px;
      background: #fff;
      color: var(--primary-800);
      font-family: 'Kanit', sans-serif;
      font-size: 14px;
      font-weight: 600;
      text-decoration: none;
      transition: background .2s ease, border-color .2s ease, transform .2s ease;
    }

    .register-link:hover {
      transform: translateY(-1px);
      border-color: #b9d9d4;
      background: var(--primary-50);
    }

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

      .intro-panel {
        display: none;
      }

      .auth-panel {
        min-height: 100vh;
        padding: 28px 20px;
        border-left: 0;
        background: transparent;
      }

      .mobile-brand {
        display: flex;
        align-items: center;
        gap: 12px;
        font-family: 'Kanit', sans-serif;
        font-size: 14px;
        font-weight: 600;
      }

      .mobile-brand .brand-mark {
        width: 40px;
        height: 40px;
        color: #fff;
        background: linear-gradient(135deg, var(--primary-900), var(--primary-500));
        border: 0;
      }
    }

    @media (max-width: 560px) {
      body {
        background:
          radial-gradient(circle at 100% 0%, rgba(255, 255, 255, .14), transparent 28%),
          linear-gradient(160deg, var(--primary-950), var(--primary-700));
      }

      .auth-panel {
        align-items: flex-start;
        padding: 16px;
      }

      .auth-card {
        margin: 10px 0;
        padding: 24px 20px;
        border-radius: 22px;
      }

      .back-home {
        margin-bottom: 18px;
      }

      .auth-heading {
        margin-bottom: 22px;
      }

      .auth-heading h2 {
        font-size: 30px;
      }

      .login-box {
        padding: 18px;
      }

      .btn-thai-id {
        min-height: 56px;
        font-size: 15px;
      }
    }

    @media (prefers-reduced-motion: reduce) {
      *,
      *::before,
      *::after {
        scroll-behavior: auto !important;
        transition: none !important;
        animation: none !important;
      }
    }