:root {
      --primary-green: #071f18;
      --secondary-green: #0b2b20;
      --lime-green: #2ecc71;
      --emerald-green: #1fa65a;
      --dark-green: #041712;
      --glass-bg: rgba(255, 255, 255, 0.03);
      --text: #e6f6ea;
      --muted: rgba(230, 246, 234, 0.85);
    }

    /* Reset & Base */
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    html, body {
      height: 100%;
    }

    body {
      font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
      background: linear-gradient(135deg, var(--primary-green) 0%, var(--secondary-green) 100%);
      min-height: 100vh;
      color: var(--text);
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

    .container {
      max-width: 1400px;
      margin: 0 auto;
      padding: 0 20px;
    }

    /* Header */
    header {
      background: rgba(4, 15, 12, 0.85);
      backdrop-filter: blur(8px);
      padding: 12px 0;
      box-shadow: 0 6px 30px rgba(0, 0, 0, 0.35);
      position: fixed;
      width: 100%;
      top: 0;
      z-index: 1000;
      border-bottom: 1px solid rgba(255, 255, 255, 0.04);
    }

    .header-content {
      display: flex;
      align-items: center;
      justify-content: center;
      min-height: 84px;
      gap: 30px;
    }

    .header-left {
      display: flex;
      justify-content: center;
      align-items: center;
    }

    .header-center {
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      white-space: nowrap;
    }

    .header-right {
      display: flex;
      justify-content: center;
      align-items: center;
    }

    .logo-section {
      display: flex;
      align-items: center;
      gap: 20px;
      justify-content: center;
    }

    .isu-logo {
      width: 60px;
      height: 60px;
      border-radius: 50%;
      overflow: hidden;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
      animation: pulse 3s ease-in-out infinite;
      background: rgba(255, 255, 255, 0.1);
      flex-shrink: 0;
    }

    .isu-logo img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      border-radius: 50%;
    }

    .title-section {
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      text-align: center;
    }

    .header-center h1 {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--text);
      text-transform: uppercase;
      letter-spacing: 0.6px;
      line-height: 1.2;
      margin: 0 0 4px 0;
      white-space: nowrap;
    }

    .header-center .subtitle {
      color: var(--muted);
      font-size: 0.85rem;
      font-weight: 500;
      opacity: 0.95;
      margin: 0;
      white-space: nowrap;
    }

    .ccsict-logo-container {
      width: 60px;
      height: 60px;
      border-radius: 50%;
      overflow: hidden;
      display: flex;
      align-items: center;
      justify-content: center;
      background: rgba(255, 255, 255, 0.1);
      box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
      flex-shrink: 0;
    }

    .ccsict-logo {
      width: 50px;
      height: 50px;
      object-fit: contain;
      opacity: 0.9;
    }

    .title-section h1 {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--text);
      text-transform: uppercase;
      letter-spacing: 0.6px;
      line-height: 1.2;
      margin: 0 0 4px 0;
      white-space: nowrap;
    }

    .title-section .subtitle {
      color: var(--muted);
      font-size: 0.85rem;
      font-weight: 500;
      opacity: 0.95;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 10px;
      margin: 0;
      white-space: nowrap;
    }

    .nav-links {
      display: flex;
      gap: 18px;
      align-items: center;
    }

    .nav-link {
      color: var(--muted);
      text-decoration: none;
      padding: 10px 14px;
      border-radius: 12px;
      transition: all 0.18s ease;
      font-weight: 600;
    }

    .nav-link:hover {
      background: rgba(255, 255, 255, 0.03);
      color: var(--text);
      transform: translateY(-2px);
    }

    /* Buttons */
    .btn {
      padding: 12px 26px;
      border: none;
      border-radius: 40px;
      font-size: 0.95rem;
      font-weight: 700;
      cursor: pointer;
      transition: all 0.25s ease;
      display: inline-flex;
      align-items: center;
      gap: 10px;
      text-transform: uppercase;
      letter-spacing: 0.8px;
      text-decoration: none;
      color: var(--text);
    }

    .btn-primary {
      background: linear-gradient(135deg, var(--lime-green), var(--emerald-green));
      color: #06220f;
      box-shadow: 0 10px 30px rgba(46, 204, 113, 0.12);
    }

    .btn-primary:hover {
      transform: translateY(-3px) scale(1.02);
      box-shadow: 0 14px 40px rgba(46, 204, 113, 0.18);
    }

    .btn-secondary {
      background: rgba(255, 255, 255, 0.02);
      color: var(--muted);
      border: 1px solid rgba(255, 255, 255, 0.04);
    }

    .btn-secondary:hover {
      background: rgba(255, 255, 255, 0.03);
      color: var(--text);
      border-color: rgba(255, 255, 255, 0.06);
    }

    /* Hero Section */
    .hero-section {
      padding: 140px 0 80px;
      position: relative;
    }

    .hero-content {
      display: grid;
      grid-template-columns: 1fr auto;
      gap: 64px;
      align-items: center;
      position: relative;
      z-index: 2;
    }

    .hero-text h1 {
      font-size: 3.6rem;
      font-weight: 800;
      line-height: 1.05;
      margin-bottom: 18px;
      color: var(--text);
    }

    .hero-text .highlight {
      display: block;
      color: var(--lime-green);
      font-size: 4rem;
      font-weight: 900;
      background: linear-gradient(90deg, #aaf5c8 0%, var(--lime-green) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .hero-text p {
      font-size: 1.05rem;
      line-height: 1.7;
      margin-bottom: 30px;
      color: var(--muted);
      max-width: 640px;
    }

    .hero-buttons {
      display: flex;
      gap: 14px;
      align-items: center;
      margin-top: 20px;
    }

    .hero-graphic {
      width: 320px;
      height: 320px;
      background: radial-gradient(circle at 30% 20%, rgba(46, 204, 113, 0.06) 0%, rgba(18, 66, 48, 0.14) 40%, rgba(7, 31, 22, 0.18) 100%);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
      border: 2px solid rgba(255, 255, 255, 0.03);
      box-shadow: 0 30px 70px rgba(2, 6, 3, 0.7);
      animation: float 8s ease-in-out infinite;
    }

    .hero-graphic .icon {
      font-size: 4.6rem;
      z-index: 1;
      color: rgba(230, 246, 234, 0.95);
      text-shadow: 0 6px 30px rgba(12, 40, 28, 0.6);
    }

    /* Feature Cards */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 28px;
    }

    .feature-card {
      background: rgba(255, 255, 255, 0.02);
      border: 1px solid rgba(46, 204, 113, 0.06);
      backdrop-filter: blur(12px);
      border-radius: 18px;
      padding: 34px 26px;
      text-align: center;
      transition: all 0.35s ease;
      box-shadow: 0 18px 44px rgba(0, 0, 0, 0.45);
    }

    .feature-card:hover {
      transform: translateY(-10px);
      border-color: rgba(46, 204, 113, 0.12);
      box-shadow: 0 30px 60px rgba(0, 0, 0, 0.55);
    }

    .feature-icon {
      font-size: 2.6rem;
      margin-bottom: 18px;
      color: var(--lime-green);
    }

    .feature-card h3 {
      font-size: 1.05rem;
      font-weight: 700;
      margin-bottom: 12px;
      color: var(--text);
      text-transform: uppercase;
      letter-spacing: 0.6px;
    }

    .feature-card p {
      color: var(--muted);
      line-height: 1.6;
      font-size: 0.95rem;
    }

    /* Login Section */
    .login-section {
      background: rgba(6, 18, 13, 0.45);
      border: 1px solid rgba(46, 204, 113, 0.06);
      backdrop-filter: blur(12px);
      box-shadow: 0 25px 60px rgba(0, 0, 0, 0.6);
      border-radius: 20px;
      padding: 44px 36px;
      max-width: 540px;
      margin: 60px auto 120px;
    }

    .login-section::before {
      content: "";
      position: absolute;
      left: 50%;
      transform: translateX(-50%);
      top: calc(100% - 30px);
      width: 80px;
      height: 4px;
      background: linear-gradient(90deg, var(--lime-green), var(--emerald-green));
      border-radius: 4px;
      opacity: 0.9;
    }

    .login-title {
      text-align: center;
      color: var(--text);
      font-size: 1.8rem;
      margin-bottom: 26px;
      font-weight: 800;
      text-transform: uppercase;
      letter-spacing: 0.8px;
    }

    .form-group {
      margin-bottom: 18px;
    }

    .form-group label {
      display: block;
      color: var(--muted);
      margin-bottom: 8px;
      font-weight: 700;
      font-size: 0.95rem;
      text-transform: uppercase;
      letter-spacing: 0.4px;
    }

    .form-group input, .form-group select {
      width: 100%;
      padding: 14px 18px;
      border: 1px solid rgba(255, 255, 255, 0.04);
      border-radius: 12px;
      font-size: 1rem;
      transition: all 0.22s ease;
      background: rgba(255, 255, 255, 0.02);
      color: var(--text);
      outline: none;
    }

    .form-group input::placeholder {
      color: rgba(230, 246, 234, 0.65);
    }

    .form-group input:focus, .form-group select:focus {
      border-color: var(--lime-green);
      box-shadow: 0 6px 30px rgba(46, 204, 113, 0.08);
      transform: translateY(-2px);
      background: rgba(255, 255, 255, 0.02);
    }

    .login-btn {
      width: 100%;
      background: linear-gradient(135deg, var(--lime-green), var(--emerald-green));
      color: #06220f;
      padding: 14px;
      border: none;
      border-radius: 12px;
      font-size: 1rem;
      font-weight: 800;
      cursor: pointer;
      transition: all 0.22s ease;
      margin-top: 12px;
      letter-spacing: 0.8px;
    }

    .login-btn:hover {
      transform: translateY(-3px);
      box-shadow: 0 18px 50px rgba(46, 204, 113, 0.12);
    }

    /* Footer */
    footer {
      background: linear-gradient(90deg, var(--dark-green) 60%, var(--primary-green) 100%);
      backdrop-filter: blur(8px);
      color: var(--text);
      text-align: center;
      padding: 48px 0;
      margin-top: 60px;
      border-top: 1px solid rgba(255, 255, 255, 0.04);
    }

    .footer-content p {
      margin-bottom: 8px;
      opacity: 0.95;
      font-size: 0.95rem;
    }

    .footer-content p:first-child {
      font-weight: 700;
      font-size: 1rem;
    }

    /* Animations */
    @keyframes float {
      0%, 100% { transform: translateY(0px) rotate(0deg); }
      33% { transform: translateY(-10px) rotate(1deg); }
      66% { transform: translateY(-5px) rotate(-1deg); }
    }

    @keyframes pulse {
      0%, 100% { box-shadow: 0 0 18px rgba(46, 204, 113, 0.08); }
      50% { box-shadow: 0 0 30px rgba(46, 204, 113, 0.14); }
    }

    @keyframes fadeInUp {
      from { opacity: 0; transform: translateY(24px); }
      to { opacity: 1; transform: translateY(0); }
    }

    .hero-section, .features-section, .login-section {
      animation: fadeInUp 0.9s ease-out both;
    }

    /* Responsive */
    @media (max-width: 1024px) {
      .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 36px;
      }

      .hero-graphic {
        margin: 0 auto;
      }

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

    @media (max-width: 768px) {
      .nav-links { display: none; }
      
      .header-content { 
        display: flex;
        flex-direction: row;
        align-items: center;
        justify-content: center;
        gap: 15px; 
        text-align: center;
        padding: 10px 0;
        min-height: 70px;
      }
      
      .header-left, .header-right {
        display: flex;
        justify-content: center;
        align-items: center;
      }
      
      .header-center {
        align-items: center;
        flex: 1;
        max-width: 200px;
      }
      
      .isu-logo, .ccsict-logo-container {
        width: 40px;
        height: 40px;
      }
      
      .ccsict-logo {
        width: 32px;
        height: 32px;
      }
      
      .header-center h1 { 
        font-size: 0.9rem; 
        margin-bottom: 2px;
        line-height: 1.1;
      }
      
      .header-center .subtitle { 
        font-size: 0.65rem; 
        line-height: 1.2;
      }
      
      .hero-text h1 { font-size: 2.2rem; }
      .hero-text .highlight { font-size: 2.6rem; }
      .hero-graphic { width: 220px; height: 220px; }
      .features-grid { grid-template-columns: 1fr; }
      .login-section { padding: 28px 18px; margin: 32px 8px 80px; }
    }