/* --- CSS Variables --- */
:root {
    /* Light Mode */
    --bg-primary-light: #f0f2f5;
    --bg-secondary-light: #ffffff;
    --bg-tertiary-light: #e2e4e8; /* For hover/active states */
    --text-primary-light: #202124;
    --text-secondary-light: #5f6368;
    --border-color-light: #dadce0;
    --shadow-color-light: rgba(0, 0, 0, 0.1);
    --google-blue: #1a73e8;
    --google-blue-hover: #176ad1;
    --google-red: #ea4335;
    --google-red-hover: #d13a2d;
    /* Dark Mode */
    --bg-primary-dark: #202124;
    --bg-secondary-dark: #2f3034;
    --bg-tertiary-dark: #3c4043;
    --text-primary-dark: #e8eaed;
    --text-secondary-dark: #bdc1c6;
    --border-color-dark: #5f6368;
    --shadow-color-dark: rgba(0, 0, 0, 0.4);
    /* Default to Light Mode values */
    --bg-primary: var(--bg-primary-light);
    --bg-secondary: var(--bg-secondary-light);
    --bg-tertiary: var(--bg-tertiary-light);
    --text-primary: var(--text-primary-light);
    --text-secondary: var(--text-secondary-light);
    --border-color: var(--border-color-light);
    --shadow-color: var(--shadow-color-light);
    /* Bootstrap Overrides */
    --bs-primary: var(--google-blue);
    --bs-primary-rgb: 26, 115, 232;
}

/* --- Dark Mode specific overrides --- */
body.dark-mode {
    --bg-primary: var(--bg-primary-dark);
    --bg-secondary: var(--bg-secondary-dark);
    --bg-tertiary: var(--bg-tertiary-dark);
    --text-primary: var(--text-primary-dark);
    --text-secondary: var(--text-secondary-dark);
    --border-color: var(--border-color-dark);
    --shadow-color: var(--shadow-color-dark);
}
/* No global filter for dark mode, relying on variable changes for better control */

/* --- Global Styles using Variables --- */
body {
    font-family: 'Roboto', sans-serif;
    background-color: var(--bg-primary);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    line-height: 1.5;
    color: var(--text-primary);
    transition: background-color 0.3s ease, color 0.3s ease;
}

.login-container {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    box-shadow: 0 1px 3px var(--shadow-color);
    padding: 48px 40px 36px;
    width: 448px;
    max-width: 90%;
    text-align: center;
    position: relative;
    transition: background-color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.login-logo img {
    height: 24px;
    margin-bottom: 24px;
}

.login-title {
    font-size: 24px;
    font-weight: 400;
    line-height: 32px;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.login-subtitle {
    font-size: 16px;
    font-weight: 400;
    line-height: 24px;
    color: var(--text-secondary);
    margin-bottom: 24px;
}


/* Custom style for Floating Labels */
.form-floating > label {
    position: absolute;
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
    font-size: 16px;
    pointer-events: none;
    transition: all 0.2s ease;
    background-color: var(--bg-secondary); /* Màu nền mặc định của label */
    padding: 0 4px;
    transform-origin: left center;
    height: auto;
}

.form-floating > .form-control:focus ~ label,
.form-floating > .form-control:not(:placeholder-shown):not(.is-invalid) ~ label, /* Thêm .not(.is-invalid) */
.form-floating > .form-control:not(:placeholder-shown).is-invalid ~ label /* Giữ lại nếu bạn có style riêng cho invalid floating label */ {
    top: 0;
    font-size: 12px;
    color: var(--google-blue);
    transform: translateY(-50%) scale(0.75);
    padding: 0 4px;
    margin-left: -4px;
    /* Đảm bảo màu nền của label khi nó nổi lên, sử dụng !important nếu cần */
    background-color: var(--bg-secondary) !important; /* Đã thêm !important */
}

/* Đảm bảo màu của label khi input invalid không bị biến thành google-blue */
.form-floating > .form-control.is-invalid:focus ~ label,
.form-floating > .form-control.is-invalid:not(:placeholder-shown) ~ label {
    color: var(--google-red) !important; /* Đặt lại màu đỏ cho label khi input invalid */
}

.form-control {
    color: var(--text-primary);
    background-color: var(--bg-secondary);
    border-color: var(--border-color);
    transition: border-color 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease, color 0.3s ease;
}

    .form-control:focus {
        border-color: var(--google-blue) !important;
        box-shadow: 0 1px 0 0 var(--google-blue) !important;
    }

    .form-control.is-invalid {
        border-color: var(--google-red) !important;
        box-shadow: 0 1px 0 0 var(--google-red) !important;
    }

.form-text {
    color: var(--google-red) !important;
    text-align: left;
    margin-top: 5px;
    display: none;
    font-size: 0.875em;
}

    .form-text.is-active {
        display: block;
    }

.link-text {
    color: var(--google-blue) !important;
    text-decoration: none;
    font-size: 14px;
    display: inline-block;
    margin-top: 8px;
    /* margin-bottom: 24px; Adjusted for remember me checkbox */
    transition: color 0.3s ease;
}

    .link-text:hover {
        color: var(--google-blue-hover) !important;
        text-decoration: underline;
    }

/* Remember Me checkbox styling */
.form-check {
    text-align: left;
    margin-top: 15px; /* Space between password field and checkbox */
    margin-bottom: 24px; /* Space before login instruction */
}

.form-check-input {
    margin-top: 0.25em; /* Align checkbox */
    border-color: var(--border-color);
    background-color: var(--bg-secondary);
}

    .form-check-input:checked {
        background-color: var(--google-blue);
        border-color: var(--google-blue);
    }

    .form-check-input:focus {
        box-shadow: 0 0 0 0.25rem rgba(26, 115, 232, 0.25);
        border-color: var(--google-blue);
    }

.form-check-label {
    color: var(--text-secondary);
    font-size: 14px;
}


.login-instruction {
    font-size: 14px;
    color: var(--text-secondary);
    text-align: left;
    margin-top: 24px;
}

.login-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 32px;
}

.btn-create-account {
    color: var(--google-blue) !important;
    text-decoration: none;
    font-weight: 500;
    padding: 8px 0;
    background-color: transparent !important;
    border: none !important;
    font-size: 14px;
    transition: color 0.3s ease;
}

    .btn-create-account:hover {
        color: var(--google-blue-hover) !important;
        text-decoration: underline;
    }

.btn-login {
    background-color: var(--google-blue) !important;
    color: #ffffff !important;
    padding: 10px 24px !important;
    border: none !important;
    border-radius: 4px !important;
    font-size: 14px !important;
    font-weight: 500 !important;
    cursor: pointer;
    transition: background-color 0.3s ease !important;
}

    .btn-login:hover {
        background-color: var(--google-blue-hover) !important;
    }

/* --- Dark/Light Mode Toggle Button --- */
.theme-toggle-btn {
    position: absolute;
    top: 20px;
    right: 20px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    font-size: 1.2em;
    box-shadow: 0 1px 3px var(--shadow-color);
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
    z-index: 10;
}

    .theme-toggle-btn:hover {
        background-color: var(--bg-tertiary);
        color: var(--text-primary);
    }

/* Responsive adjustments */
@media (max-width: 500px) {
    .login-container {
        padding: 30px 20px 25px;
        border: none;
        box-shadow: none;
        border-radius: 0;
    }

    body {
        background-color: var(--bg-secondary);
    }

    .theme-toggle-btn {
        top: 15px;
        right: 15px;
        width: 35px;
        height: 35px;
        font-size: 1em;
    }
}