:root {
    --background-color: #08041b;
    --container-color: #211e33;
    --text-color: #FFFFFF;
    --error-color: #FF0000;
    --button-gradient-left: #FF6200;
    --button-gradient-right: #FF0000;
    --secondary-button-bg: #E0E0E0;
    --secondary-button-text: #000000;
    --border-radius: 10px;
    --transition-speed: 0.3s;
}

/* Reset básico */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Roboto', sans-serif;
}

body {
    background-color: var(--background-color);
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    margin-top: 40px;
}

.app-title {
    color: var(--text-color);
    font-size: 2rem;
    margin-bottom: 40px;
    text-align: center;
    font-weight: 600;
}

.main-container {
    background-color: var(--container-color);
    border: none;
    border-radius: var(--border-radius);
    padding: 2rem;
    width: 100%;
    max-width: 700px;
    position: relative;
}

.upload-section {
    background-color: var(--container-color);
    padding: 15px;
    border-radius: var(--border-radius);
    text-align: center;
    position: relative;
}

.instructions {
    color: var(--text-color);
    font-size: 1.4em;
    margin-bottom: 15px;
    line-height: 1.3;
}

.upload-input {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-bottom: 10px;
}

.upload-input .custom-file-label {
    position: relative;
    display: inline-block;
    cursor: pointer;
    background-color: #FFFFFF;
    border: 1px solid #FFFFFF;
    padding: 6px 12px;
    border-radius: var(--border-radius);
    color: #333333;
    font-size: 1em;
}

.upload-input .custom-file-label span {
    display: inline-block;
}

.upload-input input[type="file"] {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

.upload-input input[type="file"]:invalid:not(:focus) + span {
    border-color: var(--error-color);
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='none' stroke='%23FF0000' viewBox='0 0 12 12'%3E%3Ccircle cx='6' cy='6' r='4.5'/%3E%3Cpath stroke-linejoin='round' d='M5.8 3.6h.4L6 6.5z'/%3E%3Ccircle cx='6' cy='8.2' r='.6' fill='%23FF0000' stroke='none'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right calc(0.375em + 0.1875rem) center;
    background-size: calc(0.75em + 0.375rem) calc(0.75em + 0.375rem);
}

.upload-input input[type="file"]:focus + span {
    outline: 2px solid #FFFFFF;
    outline-offset: 2px;
}

.image-icon {
    width: 32px;
    height: 32px;
    color: var(--text-color);
}

.color-count {
    margin-top: 10px;
    text-align: center;
}

.color-count label {
    color: var(--text-color);
    font-size: 1em;
    margin-right: 10px;
}

.color-count select {
    padding: 5px;
    border-radius: var(--border-radius);
    border: 1px solid #FFFFFF;
    background-color: #FFFFFF;
    color: #333333;
    font-size: 1em;
    cursor: pointer;
}

.color-count select:invalid:not(:focus) {
    border-color: var(--error-color);
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='none' stroke='%23FF0000' viewBox='0 0 12 12'%3E%3Ccircle cx='6' cy='6' r='4.5'/%3E%3Cpath stroke-linejoin='round' d='M5.8 3.6h.4L6 6.5z'/%3E%3Ccircle cx='6' cy='8.2' r='.6' fill='%23FF0000' stroke='none'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right calc(0.375em + 0.1875rem) center;
    background-size: calc(0.75em + 0.375rem) calc(0.75em + 0.375rem);
}

.color-count select:focus {
    outline: 2px solid #FFFFFF;
    outline-offset: 2px;
}

.extract-button {
    background: linear-gradient(90deg, var(--button-gradient-left), var(--button-gradient-right));
    color: var(--text-color);
    border: none;
    padding: 10px;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 1.2em;
    font-weight: 600;
    display: block;
    width: 100%;
    max-width: 250px;
    margin-left: auto;
    margin-right: auto;
    transition: transform var(--transition-speed) ease;
}

.extract-button.outside-white {
    position: static;
    margin-top: 25px;
}

.extract-button:hover {
    transform: translateY(-2px);
    background: linear-gradient(90deg, var(--button-gradient-right), var(--button-gradient-left));
}

.extract-button:active {
    transform: translateY(0);
}

.results-section {
    background-color: var(--container-color);
    padding: 20px;
    border-radius: var(--border-radius);
    margin-top: 20px;
    text-align: center;
    width: 100%;
}

#preview {
    max-width: 100%;
    max-height: 450px;
    margin: 15px auto;
    border-radius: var(--border-radius);
    border: 1px solid #FFFFFF;
    display: block;
}

.color-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    justify-content: center;
    margin-top: 15px;
}

.color-box {
    display: flex;
    align-items: center;
    gap: 10px;
    background-color: var(--container-color);
    padding: 10px;
    border-radius: var(--border-radius);
    border: 1px solid rgba(255, 255, 255, 0.1);
    min-width: 220px;
}

.color-swatch {
    width: 60px;
    height: 60px;
    border-radius: var(--border-radius);
    border: 1px solid #FFFFFF;
}

.color-codes {
    color: var(--text-color);
    font-size: 1em;
    line-height: 1.4;
}

.download-buttons {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-top: 20px;
}

.download-buttons button {
    background-color: var(--secondary-button-bg);
    color: var(--secondary-button-text);
    border: none;
    padding: 8px 20px;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 1em;
    transition: background-color var(--transition-speed) ease;
}

.download-buttons button:hover {
    background-color: #CCCCCC;
}

.reset-button {
    background: linear-gradient(90deg, var(--button-gradient-left), var(--button-gradient-right));
    color: var(--text-color);
    border: none;
    padding: 10px;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 1.2em;
    font-weight: 600;
    display: block;
    width: 100%;
    max-width: 250px;
    margin: 20px auto 0 auto;
    transition: transform var(--transition-speed) ease;
}

.reset-button:hover {
    transform: translateY(-2px);
    background: linear-gradient(90deg, var(--button-gradient-right), var(--button-gradient-left));
}

.reset-button:active {
    transform: translateY(0);
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--background-color);
}

::-webkit-scrollbar-thumb {
    background: #FFFFFF;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #CCCCCC;
}

/* Responsividad */
@media (max-width: 600px) {
    .app-title {
        font-size: 1.5rem;
    }

    .main-container {
        padding: 1.5rem;
        max-width: 100%;
    }

    .upload-section {
        padding: 10px;
    }

    .instructions {
        font-size: 1.2em;
    }

    .extract-button,
    .reset-button {
        font-size: 1em;
        padding: 8px;
    }

    #preview {
        max-height: 300px;
    }

    .color-box {
        min-width: 100%;
    }
}