:root {
    --app-primary: #5865f2;
    --app-primary-rgb: 88, 101, 242;

    /* Dark Theme (Default) */
    --login-bg: linear-gradient(315deg, #000000, #414141, #000000, #5865f2);
    --login-bg-size: 400% 400%;
    --login-bg-animation: gradientBG 25s ease infinite;
    --login-card-bg: rgba(30, 31, 34, 0.6);
    --login-card-border: 1px solid rgba(255, 255, 255, 0.2);
    --login-text-color: #fff;
    --login-input-bg: rgba(0, 0, 0, 0.2);
    --login-input-border: rgba(255, 255, 255, 0.2);
    --login-input-color: #fff;
    --login-input-placeholder: rgba(255, 255, 255, 0.5);
}

body {
    font-family: 'Inter', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: var(--login-bg);
    background-size: var(--login-bg-size);
    animation: var(--login-bg-animation);
    transition: background 0.3s ease-in-out;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

@keyframes gradientBG {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.login-container {
    width: 100%;
    max-width: 420px;
    padding: 15px;
}

.login-card {
    background: var(--login-card-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: var(--login-card-border);
    border-radius: .75rem;
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
    color: var(--login-text-color);
    animation: fadeIn 0.6s ease-out;
    transition: background 0.3s ease-in-out, border 0.3s ease-in-out, color 0.3s ease-in-out;
}

.login-header {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: 2rem !important;
}

.login-header .bi-whatsapp {
    color: var(--app-primary);
    font-size: 3.5rem;
    animation: pulse-glow 4s ease-in-out infinite;
    text-shadow: 0 0 15px rgba(var(--app-primary-rgb), 0.5);
}

.form-control {
    background-color: var(--login-input-bg);
    border-color: var(--login-input-border);
    border-left: none;
    color: var(--login-input-color);
    transition: border-color .15s ease-in-out, box-shadow .15s ease-in-out;
    height: 48px;
}

.input-group .form-control:focus {
    border-left: none;
}

.form-control:focus {
    color: var(--login-input-color);
    background-color: var(--login-input-bg);
    background-clip: padding-box;
    border-color: var(--app-primary);
    box-shadow: 0 0 0 0.25rem rgba(var(--app-primary-rgb), 0.25);
}

.form-control::placeholder {
    color: var(--login-input-placeholder);
    opacity: 1;
}

.btn-primary {
    --bs-btn-bg: var(--app-primary);
    --bs-btn-border-color: var(--app-primary);
    --bs-btn-hover-bg: #4a56d4;
    --bs-btn-hover-border-color: #4551c5;
    font-weight: 600;
    transition: transform 0.2s ease-out, box-shadow 0.2s ease-out;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(var(--app-primary-rgb), 0.3);
}

.form-check-input {
    transition: background-color .15s ease-in-out, border-color .15s ease-in-out;
}
.form-check-input:checked {
    background-color: var(--app-primary);
    border-color: var(--app-primary);
}

.input-group-text {
    background-color: var(--login-input-bg);
    border: 1px solid var(--login-input-border);
    border-right: none;
    color: var(--login-input-placeholder);
}

.input-group:focus-within .input-group-text {
    border-color: var(--app-primary);
    color: var(--app-primary);
}

#showPassword {
    border-left: none;
    border-color: var(--login-input-border);
}
.input-group:focus-within #showPassword {
    border-color: var(--app-primary);
}

.theme-toggle-container {
    position: absolute;
    top: 1rem;
    right: 1rem;
}

/* --- Light Theme --- */
body.light-theme {
    --login-bg: #f0f2f5;
    --login-bg-animation: none;
    --login-card-bg: #ffffff;
    --login-card-border: 1px solid #dee2e6;
    --login-text-color: #212529;
    --login-input-bg: #fff;
    --login-input-border: #ced4da;
    --login-input-color: #212529;
    --login-input-placeholder: #adb5bd; /* A lighter, more subtle placeholder color */
}

body.light-theme .login-card {
    box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.15);
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
}

body.light-theme .form-control:focus {
    color: var(--login-input-color);
    background-color: #fff;
}

body.light-theme .input-group-text {
    color: #6c757d;
}

body.light-theme #showPassword {
    --bs-btn-color: #6c757d;
    --bs-btn-hover-bg: #e9ecef;
    --bs-btn-hover-border-color: #ced4da;
    --bs-btn-active-bg: #dee2e6;
}

body.light-theme #themeToggleBtn {
    --bs-btn-color: #495057;
    --bs-btn-border-color: #ced4da;
    --bs-btn-hover-color: #fff;
    --bs-btn-hover-bg: #495057;
    --bs-btn-hover-border-color: #495057;
}

body.light-theme .alert-danger {
    --bs-alert-bg: #f8d7da;
    --bs-alert-border-color: #f1aeb5;
    --bs-alert-color: #58151c;
}