:root {
    /* Default Purple Theme */
    --theme-purple-dark: #2c0044;
    --theme-purple-medium: #6a0595;
    --theme-purple-light: #9d33d1;
    --theme-text-color: #e0e0e0;
    --theme-border-color: #6a0595;
    --theme-bg-color: #1a0029;
    --theme-blackhole-inner: rgba(106, 5, 149, 1);
    --theme-blackhole-mid: rgba(157, 51, 209, 0.8);
    --theme-blackhole-outer: rgba(106, 5, 149, 0);
    --theme-blackhole-particles: rgba(255, 255, 255, var(--particle-opacity, 0.5));
}

/* Blue Theme */
body.theme-blue {
    --theme-purple-dark: #002c44;
    --theme-purple-medium: #056a95;
    --theme-purple-light: #339dd1;
    --theme-text-color: #e0e0e0;
    --theme-border-color: #056a95;
    --theme-bg-color: #001a29;
    --theme-blackhole-inner: rgba(5, 106, 149, 1);
    --theme-blackhole-mid: rgba(51, 157, 209, 0.8);
    --theme-blackhole-outer: rgba(5, 106, 149, 0);
    --theme-blackhole-particles: rgba(255, 255, 255, var(--particle-opacity, 0.5));
}

/* Black Theme */
body.theme-black {
    --theme-purple-dark: #1a1a1a;
    --theme-purple-medium: #333333;
    --theme-purple-light: #555555;
    --theme-text-color: #e0e0e0;
    --theme-border-color: #333333;
    --theme-bg-color: #000000;
    --theme-blackhole-inner: rgba(51, 51, 51, 1);
    --theme-blackhole-mid: rgba(85, 85, 85, 0.8);
    --theme-blackhole-outer: rgba(51, 51, 51, 0);
    --theme-blackhole-particles: rgba(200, 200, 200, var(--particle-opacity, 0.5));
}

/* White Theme */
body.theme-white {
    --theme-purple-dark: #e0e0e0;
    --theme-purple-medium: #cccccc;
    --theme-purple-light: #aaaaaa;
    --theme-text-color: #333333;
    --theme-border-color: #cccccc;
    --theme-bg-color: #ffffff;
    --theme-blackhole-inner: rgba(204, 204, 204, 1);
    --theme-blackhole-mid: rgba(170, 170, 170, 0.8);
    --theme-blackhole-outer: rgba(204, 204, 204, 0);
    --theme-blackhole-particles: rgba(50, 50, 50, var(--particle-opacity, 0.5));
}


body {
    font-family: 'Arial', sans-serif;
    background-color: var(--theme-bg-color);
    color: var(--theme-text-color);
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
    padding-top: 50px;
    position: relative;
    overflow: hidden;
    transition: background-color 0.5s, color 0.5s;
}

.hidden {
    display: none !important;
}

#blackHoleCanvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: -1;
}

.container {
    width: 90%;
    max-width: 1200px;
    text-align: center;
    position: relative;
    z-index: 1;
}

.title-section {
    position: relative;
    width: 100%;
    height: 300px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    margin-bottom: 20px;
}

.title {
    font-size: 4rem;
    color: var(--theme-text-color);
    text-shadow: 0 0 15px var(--theme-purple-light), 0 0 25px var(--theme-purple-medium);
    position: relative;
    z-index: 2;
    text-transform: uppercase;
    letter-spacing: 5px;
    margin-bottom: 20px;
}

.auth-controls {
    position: relative;
    z-index: 2;
    display: flex;
    gap: 10px;
    align-items: center;
}

.auth-controls #userEmailDisplay {
    font-size: 1rem;
    font-weight: bold;
    color: var(--theme-purple-light);
    margin-right: 10px;
}

.filters {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.filter-btn {
    background-color: transparent;
    border: 2px solid var(--theme-border-color);
    color: var(--theme-text-color);
    padding: 12px 25px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: background-color 0.3s, border-color 0.3s, transform 0.2s;
    border-radius: 5px;
    text-transform: uppercase;
    backdrop-filter: blur(5px);
}

.filter-btn:hover {
    background-color: var(--theme-purple-dark);
    transform: translateY(-2px);
}

.filter-btn.active {
    background-color: var(--theme-purple-medium);
    border-color: var(--theme-purple-light);
    box-shadow: 0 0 10px var(--theme-purple-light);
}

.content {
    background-color: hsla(280, 100%, 14%, 0.7);
    background-color: var(--theme-purple-dark);
    opacity: 0.9;
    padding: 30px;
    border-radius: 10px;
    border: 2px solid var(--theme-purple-medium);
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(10px);
    transition: background-color 0.5s, border-color 0.5s, box-shadow 0.5s;
}

.category {
    display: none;
    animation: fadeIn 0.5s ease-in-out;
}

.category.active {
    display: block;
}

.category h2 {
    font-size: 2.5rem;
    border-bottom: 2px solid var(--theme-purple-light);
    padding-bottom: 10px;
    margin-bottom: 20px;
    text-transform: uppercase;
    transition: border-color 0.5s;
}

.item-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.item {
    background-color: var(--theme-bg-color);
    opacity: 0.9;
    padding: 20px;
    border: 1px solid var(--theme-border-color);
    border-radius: 8px;
    transition: transform 0.3s, box-shadow 0.3s, background-color 0.5s, border-color 0.5s;
}

.item:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.auth-page {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 0;
}

.auth-container {
    background-color: var(--theme-purple-dark);
    opacity: 0.95;
    padding: 40px;
    border-radius: 10px;
    border: 2px solid var(--theme-purple-medium);
    box-shadow: 0 0 25px rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(15px);
    width: 90%;
    max-width: 450px;
    text-align: center;
    transition: background-color 0.5s, border-color 0.5s, box-shadow 0.5s;
}

.auth-title {
    font-size: 3rem;
    color: var(--theme-text-color);
    text-shadow: 0 0 10px var(--theme-purple-light);
    margin-bottom: 30px;
    transition: color 0.5s, text-shadow 0.5s;
}

.auth-form .form-group {
    margin-bottom: 20px;
    text-align: left;
}

.auth-form label {
    display: block;
    margin-bottom: 8px;
    font-size: 1.1rem;
    color: var(--theme-purple-light);
    font-weight: bold;
    transition: color 0.5s;
}

.auth-form input[type="email"],
.auth-form input[type="password"] {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--theme-border-color);
    border-radius: 5px;
    background-color: var(--theme-bg-color);
    opacity: 0.8;
    color: var(--theme-text-color);
    font-size: 1rem;
    outline: none;
    transition: background-color 0.5s, border-color 0.5s, color 0.5s;
}

.auth-form input[type="email"]:focus,
.auth-form input[type="password"]:focus {
    border-color: var(--theme-purple-light);
    box-shadow: 0 0 8px var(--theme-purple-light);
}

.auth-button {
    background-color: var(--theme-purple-medium);
    color: var(--theme-text-color);
    padding: 12px 25px;
    border: none;
    border-radius: 5px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s, color 0.5s;
    margin-top: 15px;
    width: 100%;
}

.auth-button:hover {
    background-color: var(--theme-purple-light);
    transform: translateY(-2px);
}

.auth-link-text {
    margin-top: 20px;
    font-size: 0.95rem;
}

.auth-link-text a {
    color: var(--theme-purple-light);
    text-decoration: none;
    font-weight: bold;
    transition: color 0.2s;
}

.auth-link-text a:hover {
    color: var(--theme-text-color);
    text-decoration: underline;
}

.message {
    margin-top: 20px;
    padding: 10px;
    border-radius: 5px;
    font-size: 0.95rem;
    color: var(--theme-text-color);
    transition: background-color 0.5s, border-color 0.5s, color 0.5s;
}

.message.error {
    background-color: rgba(255, 0, 0, 0.2);
    border: 1px solid rgba(255, 0, 0, 0.5);
}

.message.success {
    background-color: rgba(0, 255, 0, 0.2);
    border: 1px solid rgba(0, 255, 0, 0.5);
}


.settings-modal {
    position: fixed;
    z-index: 10;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0,0,0,0.7);
    display: flex;
    justify-content: center;
    align-items: center;
}

.settings-modal-content {
    background-color: var(--theme-purple-dark);
    opacity: 0.95;
    margin: auto;
    padding: 30px;
    border: 2px solid var(--theme-purple-medium);
    border-radius: 10px;
    width: 80%;
    max-width: 600px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.3);
    position: relative;
    transition: background-color 0.5s, border-color 0.5s;
}

.settings-modal-content h2 {
    color: var(--theme-purple-light);
    margin-bottom: 25px;
    font-size: 2rem;
    text-shadow: 0 0 5px var(--theme-purple-medium);
    transition: color 0.5s, text-shadow 0.5s;
}

.close-button {
    color: var(--theme-text-color);
    position: absolute;
    top: 15px;
    right: 25px;
    font-size: 30px;
    font-weight: bold;
    cursor: pointer;
    transition: color 0.3s;
}

.close-button:hover,
.close-button:focus {
    color: var(--theme-purple-light);
}

.setting-option {
    margin-bottom: 25px;
    padding-bottom: 15px;
    border-bottom: 1px dashed var(--theme-border-color);
}

.setting-option:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.setting-option h3 {
    color: var(--theme-purple-light);
    font-size: 1.3rem;
    margin-bottom: 15px;
    transition: color 0.5s;
}

.theme-options label {
    display: inline-block;
    margin-right: 20px;
    cursor: pointer;
    font-size: 1rem;
    color: var(--theme-text-color);
}

.theme-options input[type="radio"] {
    margin-right: 8px;
    accent-color: var(--theme-purple-medium);
}

.transactions-display {
    margin-top: 15px;
    background-color: var(--theme-bg-color);
    padding: 15px;
    border-radius: 8px;
    border: 1px solid var(--theme-border-color);
    text-align: left;
    max-height: 200px;
    overflow-y: auto;
    transition: background-color 0.5s, border-color 0.5s;
}

.transactions-display p {
    margin: 5px 0;
    border-bottom: 1px dotted rgba(255,255,255,0.1);
    padding-bottom: 5px;
}
.transactions-display p:last-child {
    border-bottom: none;
}

.settings-btn {
    background-color: transparent;
    border: 2px solid var(--theme-border-color);
    color: var(--theme-text-color);
    padding: 8px 12px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: background-color 0.3s, border-color 0.3s, transform 0.2s;
    border-radius: 5px;
    backdrop-filter: blur(5px);
    display: flex;
    align-items: center;
    justify-content: center;
}

.settings-btn:hover {
    background-color: var(--theme-purple-dark);
    transform: translateY(-2px);
}

.gear-icon {
    width: 24px;
    height: 24px;
    fill: var(--theme-text-color);
    transition: fill 0.5s;
}
.settings-btn:hover .gear-icon {
    fill: var(--theme-purple-light);
}


@media (max-width: 768px) {
    body {
        padding-top: 20px;
    }
    .title {
        font-size: 2.5rem;
    }

    .filter-btn {
        padding: 10px 20px;
        font-size: 1rem;
    }

    .auth-title {
        font-size: 2.2rem;
    }

    .settings-modal-content {
        width: 95%;
        padding: 20px;
    }

    .close-button {
        top: 10px;
        right: 15px;
        font-size: 24px;
    }

    .setting-option h3 {
        font-size: 1.1rem;
    }
}