:root {
      --bg-main: #0B0F19;
      --card-bg: rgba(17, 24, 39, 0.65);
      --card-border: rgba(255, 255, 255, 0.08);
      --text-main: #F3F4F6;
      --text-muted: #9CA3AF;
      --accent-purple: #8B5CF6;
      --accent-pink: #EC4899;
      --accent-grad: linear-gradient(135deg, #8B5CF6 0%, #EC4899 100%);
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: 'Outfit', 'Noto Sans KR', sans-serif;
      background-color: var(--bg-main);
      color: var(--text-main);
      min-height: 100vh;
      display: flex;
      justify-content: center;
      align-items: center;
      position: relative;
      overflow: hidden;
    }

    /* 배경 데코레이션 네온 광채 */
    body::before, body::after {
      content: '';
      position: absolute;
      width: 350px;
      height: 350px;
      border-radius: 50%;
      filter: blur(120px);
      z-index: -1;
      opacity: 0.25;
    }
    body::before {
      background: var(--accent-purple);
      top: 15%;
      left: 20%;
      animation: float1 12s infinite alternate ease-in-out;
    }
    body::after {
      background: var(--accent-pink);
      bottom: 15%;
      right: 20%;
      animation: float2 12s infinite alternate ease-in-out;
    }

    @keyframes float1 {
      0% { transform: translate(0, 0) scale(1); }
      100% { transform: translate(40px, 30px) scale(1.15); }
    }
    @keyframes float2 {
      0% { transform: translate(0, 0) scale(1.1); }
      100% { transform: translate(-40px, -30px) scale(0.9); }
    }

    .login-container {
      width: 100%;
      max-width: 440px;
      padding: 1.5rem;
      animation: slideUp 0.6s cubic-bezier(0.16, 1, 0.3, 1);
    }

    @keyframes slideUp {
      from { opacity: 0; transform: translateY(40px); }
      to { opacity: 1; transform: translateY(0); }
    }

    .login-card {
      background: var(--card-bg);
      border: 1px solid var(--card-border);
      border-radius: 1.25rem;
      padding: 3rem 2.5rem;
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
      text-align: center;
    }

    .logo-area {
      margin-bottom: 2.25rem;
    }

    .logo-badge {
      display: inline-flex;
      padding: 0.6rem;
      border-radius: 0.75rem;
      background: rgba(139, 92, 246, 0.15);
      border: 1px solid rgba(139, 92, 246, 0.25);
      color: #A78BFA;
      margin-bottom: 1rem;
    }

    .logo-badge svg {
      width: 28px;
      height: 28px;
    }

    h2 {
      font-size: 1.6rem;
      font-weight: 700;
      letter-spacing: -0.025em;
      margin-bottom: 0.5rem;
      background: linear-gradient(to right, #ffffff, #d8b4fe);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .subtitle {
      font-size: 0.9rem;
      color: var(--text-muted);
      line-height: 1.4;
    }

    .form-group {
      margin-bottom: 1.25rem;
      text-align: left;
      position: relative;
    }

    .form-group label {
      display: block;
      font-size: 0.75rem;
      font-weight: 600;
      color: var(--text-muted);
      margin-bottom: 0.5rem;
      text-transform: uppercase;
      letter-spacing: 0.05em;
    }

    .input-wrapper {
      position: relative;
      display: flex;
      align-items: center;
    }

    .input-wrapper svg {
      position: absolute;
      left: 1rem;
      color: var(--text-muted);
      width: 20px;
      height: 20px;
      transition: color 0.2s;
    }

    input[type="text"], input[type="password"] {
      width: 100%;
      padding: 0.875rem 1rem 0.875rem 2.75rem;
      background: rgba(0, 0, 0, 0.3);
      border: 1px solid var(--card-border);
      border-radius: 0.75rem;
      color: var(--text-main);
      font-size: 0.95rem;
      font-family: inherit;
      outline: none;
      transition: border-color 0.25s, box-shadow 0.25s, background-color 0.25s;
    }

    input:focus {
      border-color: var(--accent-purple);
      box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.15);
      background: rgba(0, 0, 0, 0.45);
    }

    input:focus + svg {
      color: var(--accent-purple);
    }

    .btn-login {
      width: 100%;
      padding: 0.9rem;
      margin-top: 1.5rem;
      border: none;
      border-radius: 0.75rem;
      background: var(--accent-grad);
      color: #ffffff;
      font-size: 1rem;
      font-weight: 600;
      cursor: pointer;
      box-shadow: 0 4px 12px rgba(139, 92, 246, 0.3);
      transition: transform 0.2s, box-shadow 0.2s, opacity 0.2s;
      outline: none;
      display: flex;
      justify-content: center;
      align-items: center;
      gap: 0.5rem;
    }

    .btn-login:hover {
      transform: translateY(-2px);
      box-shadow: 0 6px 20px rgba(139, 92, 246, 0.45);
    }

    .btn-login:active {
      transform: translateY(0);
    }

    .btn-login:disabled {
      opacity: 0.6;
      cursor: not-allowed;
      transform: none;
      box-shadow: none;
    }

    /* Toast Notification */
    .toast {
      position: fixed;
      bottom: 2rem;
      left: 50%;
      transform: translateX(-50%) translateY(100px);
      background: rgba(239, 68, 68, 0.9);
      border: 1px solid rgba(239, 68, 68, 0.2);
      color: #ffffff;
      padding: 0.875rem 1.75rem;
      border-radius: 0.75rem;
      font-size: 0.875rem;
      font-weight: 500;
      backdrop-filter: blur(8px);
      box-shadow: 0 10px 25px rgba(239, 68, 68, 0.2);
      transition: transform 0.35s cubic-bezier(0.175, 0.885, 0.32, 1.275), opacity 0.2s;
      z-index: 1000;
      opacity: 0;
      pointer-events: none;
      white-space: nowrap;
    }
    .toast.show {
      transform: translateX(-50%) translateY(0);
      opacity: 1;
    }

    /* Spinner */
    .spinner {
      border: 2.5px solid rgba(255, 255, 255, 0.3);
      border-radius: 50%;
      border-top: 2.5px solid #ffffff;
      width: 18px;
      height: 18px;
      animation: spin 0.8s linear infinite;
      display: none;
    }

    @keyframes spin {
      0% { transform: rotate(0deg); }
      100% { transform: rotate(360deg); }
    }