:root {
      --bg-overlay: rgba(255, 255, 255, 0.6);
      --bg-gradient: linear-gradient(180deg, #eef6ff, #ffffff 40%);
      --card-bg: #ffffff;
      --text-primary: #0f172a;
      --text-secondary: #475569;
      --brand: #2563eb;
      --brand-strong: #1d4ed8;
      --ring: rgba(37, 99, 235, 0.35);
      --border: rgba(2,6,23,0.12);
      --input-bg: #ffffff;
      --shadow: 0 10px 24px rgba(2, 6, 23, 0.06);
      --success: #22c55e;
      --error: #ef4444;
    }

    [data-theme="dark"] {
      --bg-overlay: rgba(0, 0, 0, 0.5);
      --bg-gradient: linear-gradient(180deg, #0b1220, #0b1220 40%);
      --card-bg: rgba(17, 24, 39, 0.7);
      --text-primary: #e2e8f0;
      --text-secondary: #94a3b8;
      --ring: rgba(99, 102, 241, 0.35);
      --border: rgba(255,255,255,0.14);
      --input-bg: rgba(148,163,184,0.08);
      --shadow: 0 12px 30px rgba(0,0,0,0.35);
    }

    body {
      margin: 0;
      font-family: 'Segoe UI', sans-serif;
      background: url('https://files.catbox.moe/bzkzuc.jpg') center/cover no-repeat fixed, var(--bg-gradient);
      min-height: 100vh;
      display: flex;
      flex-direction: column;
      color: var(--text-primary);
    }

    .overlay {
      position: fixed;
      width: 100%;
      height: 100%;
      inset: 0;
      backdrop-filter: blur(6px);
      background-color: var(--bg-overlay);
      z-index: 0;
      pointer-events: none;
    }

    header {
      position: relative;
      z-index: 1;
      background: rgba(255,255,255,0.8);
      padding: 18px 20px;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 12px;
      border-bottom: 1px solid rgba(15,23,42,0.06);
      backdrop-filter: saturate(160%) blur(6px);
    }

    [data-theme="dark"] header {
      background: rgba(0,0,0,0.4);
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }

    .logo {
      width: 28px;
      height: 28px;
      border-radius: 8px;
      box-shadow: 0 2px 8px rgba(0,0,0,0.35);
    }

    main {
      flex: 1;
      display: flex;
      justify-content: center;
      align-items: center;
      padding: 24px;
      position: relative;
      z-index: 1;
    }

    .card {
      background: var(--card-bg);
      padding: 32px 30px;
      border-radius: 16px;
      box-shadow: var(--shadow);
      border: 1px solid var(--border);
      width: 100%;
      max-width: 400px;
      color: var(--text-primary);
    }

    [data-theme="dark"] .card {
      border: 1px solid rgba(255,255,255,0.08);
      box-shadow: 0 12px 30px rgba(0,0,0,0.35);
    }

    .card h2 {
      margin-top: 0;
      margin-bottom: 8px;
      text-align: center;
      letter-spacing: 0.3px;
      font-weight: 700;
      font-size: 26px;
    }

    .subtitle {
      margin: 0 0 24px 0;
      text-align: center;
      color: var(--text-secondary);
      font-size: 14px;
    }

    form { display: flex; flex-direction: column; gap: 16px; }
    
    .form-group { 
      margin: 0; 
      position: relative;
    }
    
    .form-group .input-icon {
      position: absolute;
      left: 15px;
      top: 50%;
      transform: translateY(-50%);
      color: var(--text-secondary);
      pointer-events: none;
      transition: color 0.2s ease;
    }

    .form-group input:focus + .input-icon {
      color: var(--brand);
    }

    .form-group input {
      padding-left: 42px;
    }

    .password-toggle {
      position: absolute;
      right: 1px;
      top: 1px;
      bottom: 1px;
      width: 44px;
      background: transparent;
      border: none;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--text-secondary);
      border-radius: 0 11px 11px 0;
    }
    .password-toggle:hover {
      color: var(--brand);
    }
    .password-toggle svg {
      width: 20px;
      height: 20px;
    }
    
    .form-group label {
      display: block;
      margin-bottom: 5px;
      font-weight: bold;
      font-size: 13px;
      color: var(--text-secondary);
    }

    .form-group input,
    .form-group select,
    .form-group button {
      box-sizing: border-box;
      width: 100%;
      height: 46px;
      padding: 0 14px;
      border: 1px solid var(--border);
      border-radius: 12px;
      outline: none;
      font-size: 14px;
      transition: box-shadow 0.2s ease, border-color 0.2s ease, background-color 0.2s ease, transform 0.06s ease;
    }

    .form-group input,
    .form-group select {
      background-color: var(--input-bg);
      color: var(--text-primary);
    }

    ::placeholder { color: #94a3b8; opacity: 1; }
    [data-theme="dark"] ::placeholder { color: #94a3b8; }

    [data-theme="dark"] .form-group input,
    [data-theme="dark"] .form-group select {
      background-color: rgba(148,163,184,0.08);
      border-color: rgba(255,255,255,0.14);
      color: #e2e8f0;
    }

    .form-group button[type="submit"] {
      padding-left: 14px; /* Reset padding for submit button */
      background: linear-gradient(135deg, var(--brand), var(--brand-strong));
      color: #ffffff;
      cursor: pointer;
      border: none;
      box-shadow: 0 6px 18px rgba(37,99,235,0.25);
      height: 48px;
      font-weight: 600;
      letter-spacing: 0.3px;
    }

    .form-group button[type="submit"]:hover {
      transform: translateY(-1px);
      box-shadow: 0 10px 24px rgba(37,99,235,0.32);
    }

    .form-group input:focus,
    .form-group select:focus {
      border-color: var(--brand-strong);
      box-shadow: 0 0 0 4px var(--ring);
    }

    .helper {
      margin-top: 8px;
      color: var(--text-secondary);
      font-size: 12px;
    }

    .error {
      margin: 6px 0 0 0;
      color: #b91c1c;
      font-size: 12px;
    }

    .theme-toggle {
      position: absolute;
      right: 16px;
      top: 50%;
      transform: translateY(-50%);
      background: transparent;
      border: 1px solid rgba(15,23,42,0.12);
      color: var(--text-primary);
      padding: 8px 10px;
      border-radius: 10px;
      cursor: pointer;
      font-size: 13px;
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }

    .theme-toggle:hover { border-color: var(--brand-strong); }

    [data-theme="dark"] .theme-toggle { border-color: rgba(255,255,255,0.18); }

    footer {
      position: relative;
      z-index: 1;
      color: var(--text-secondary);
      text-align: center;
      font-size: 12px;
      padding: 14px 10px 20px;
    }
    
    #notification-container {
      position: fixed;
      top: 20px;
      right: 20px;
      z-index: 1000;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .toast {
      background-color: var(--card-bg);
      color: var(--text-primary);
      padding: 15px 20px;
      border-radius: 12px;
      box-shadow: var(--shadow);
      border-left: 5px solid;
      opacity: 0;
      transform: translateX(100%);
      transition: all 0.5s cubic-bezier(0.68, -0.55, 0.27, 1.55);
      min-width: 280px;
      font-size: 14px;
      white-space: pre-wrap; /* Agar baris baru (\n) berfungsi */
    }

    .toast.show {
      opacity: 1;
      transform: translateX(0);
    }

    .toast.success { border-color: var(--success); }
    .toast.error { border-color: var(--error); }

    @media (max-width: 420px) {
      .card { padding: 22px; border-radius: 14px; }
      header { padding: 14px 16px; }
    }