:root {
    --bg-color: #f5f5f5;
    --text-color: #333;
    --container-bg: white;
    --border-color: #ccc;
    --highlight-color: #2196F3;
    --highlight-hover: #1976D2;
    --progress-bg: #f0f0f0;
    --primary-color: #2196F3;
    --secondary-color: #ccc;
    --textarea-bg: rgba(255, 255, 255, 0.1);
    --danger-color: #f44336;
}

[data-theme="dark"] {
    --bg-color: #1a1a1a;
    --text-color: #fff;
    --container-bg: #2d2d2d;
    --border-color: #404040;
    --highlight-color: #2196F3;
    --highlight-hover: #1976D2;
    --progress-bg: #404040;
    --primary-color: #2196F3;
    --secondary-color: #404040;
    --textarea-bg: rgba(255, 255, 255, 0.05);
    --danger-color: #f44336;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
}

body {
    min-height: 100vh;
    background: var(--bg-color);
    display: flex;
    justify-content: center;
    padding-top: 2rem;
    color: var(--text-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    width: 100%;
    max-width: 600px;
    padding: 20px;
    text-align: center;
    position: relative;
}

.theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-color);
    transition: background-color 0.3s ease;
}

.theme-toggle:hover {
    background-color: rgba(128, 128, 128, 0.2);
}

.theme-toggle svg {
    width: 24px;
    height: 24px;
}

h1 {
    color: var(--text-color);
    margin-bottom: 30px;
    font-size: 2.5rem;
    font-weight: 700;
}

.upload-container {
    background: var(--container-bg);
    border-radius: 10px;
    padding: 40px 20px;
    border: 2px dashed var(--border-color);
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: 20px;
}

.upload-container.highlight {
    border-color: var(--highlight-color);
    background: var(--container-bg);
}

.upload-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
}

.upload-content svg {
    color: var(--text-color);
    margin-bottom: 10px;
}

.upload-content p {
    color: var(--text-color);
    font-size: 1.1rem;
    line-height: 1.5;
}

button {
    background: var(--highlight-color);
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 5px;
    font-size: 1rem;
    cursor: pointer;
    transition: background 0.3s ease;
}

button:hover {
    background: var(--highlight-hover);
}

button:disabled {
    background: var(--border-color);
    cursor: not-allowed;
}

.file-list {
    margin-top: 20px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.file-item {
    background: var(--container-bg);
    padding: 10px 15px;
    border-radius: 5px;
    text-align: left;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.upload-button {
    margin-top: 20px;
    width: 100%;
    max-width: 200px;
    margin-left: auto;
    margin-right: auto;
}

.button-group {
    display: flex;
    gap: 10px;
    justify-content: center;
}

/* Progress Bar Styles */
#uploadProgress {
    margin: 20px 0;
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.progress-container {
    background: var(--container-bg);
    padding: 15px;
    border-radius: 5px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.progress-label {
    text-align: left;
    margin-bottom: 8px;
    color: var(--text-color);
    font-size: 0.9rem;
}

.progress-status {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8rem;
    color: var(--text-color);
    opacity: 0.8;
    margin-top: 8px;
}

.progress-info {
    text-align: left;
}

.progress-details {
    text-align: right;
}

.progress {
    background: var(--progress-bg);
    border-radius: 10px;
    height: 8px;
    overflow: hidden;
    margin-top: 8px;
    margin-bottom: 8px;
}

.progress-bar {
    height: 100%;
    background: var(--highlight-color);
    transition: width 0.3s ease;
}

/* Modal Styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--bg-color);
    z-index: 1000;
    display: none;
}

.modal.visible {
    display: flex;
    align-items: center;
    justify-content: center;
}

#pin-modal .modal-content {
    text-align: center;
    padding: 3rem 2rem;
    width: 100%;
    max-width: 400px;
    background-color: var(--container-bg);
    border-radius: 16px;
    box-shadow: 0 0 0 1px rgba(128, 128, 128, 0.1),
                0 8px 16px rgba(0, 0, 0, 0.1);
}

.pin-header {
    margin-bottom: 2rem;
}

.pin-header h1 {
    color: var(--text-color);
    font-size: 2.5rem;
    margin-bottom: 1rem;
    font-weight: 700;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.pin-header h2 {
    color: var(--text-color);
    opacity: 0.9;
    font-size: 1.25rem;
    font-weight: 500;
}

.pin-container {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: center;
    margin: 2rem 0;
    max-width: 100%;
    padding: 0 1rem;
}

.pin-digit {
    width: 2.5rem;
    height: 3rem;
    padding: 0;
    border: 2px solid var(--secondary-color);
    border-radius: 8px;
    background-color: var(--textarea-bg);
    color: var(--text-color);
    font-size: 1.25rem;
    text-align: center;
    transition: all 0.2s ease;
    caret-color: var(--primary-color);
}

.pin-digit:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px var(--primary-color);
    outline: none;
}

.pin-digit.filled {
    border-color: var(--primary-color);
    background-color: var(--primary-color);
    color: white;
}

.error-message {
    color: var(--danger-color);
    margin-top: 1rem;
    font-size: 0.875rem;
}

#pin-modal .modal-buttons {
    display: flex;
    justify-content: center;
    margin-top: 2rem;
}

#pin-modal .modal-buttons button.primary {
    background-color: var(--primary-color);
    color: white;
    padding: 0.75rem 2rem;
    font-size: 1rem;
    min-width: 120px;
    border-radius: 8px;
    transition: all 0.2s ease;
}

#pin-modal .modal-buttons button.primary:hover {
    background-color: var(--primary-color);
    opacity: 0.9;
    transform: translateY(-1px);
}

#pin-modal .modal-buttons button.primary:active {
    transform: translateY(0);
}

@media (max-width: 480px) {
    .container {
        padding: 10px;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    .upload-container {
        padding: 20px 10px;
    }

    .pin-container {
        gap: 0.4rem;
    }

    .pin-digit {
        width: 2.25rem;
        height: 2.75rem;
        font-size: 1.125rem;
    }
}