/* Variables for Siemens color theme */
:root {
    --siemens-corporate-blue: #003366; /* Deep blue for header, CTAs */
    --siemens-light-gray: #f0f0f0;    /* Background gray */
    --siemens-white: #ffffff;         /* Card backgrounds, text */
    --siemens-dark-gray: #333333;     /* Main text color */
    --siemens-medium-gray: #cccccc;   /* Borders, subtle elements */
    --siemens-accent-turquoise: #009999; /* For highlights, progress */
 
    --shadow-light: 0 4px 10px rgba(0,0,0,0.08);
    --shadow-medium: 0 6px 15px rgba(0,0,0,0.12);
 
    --border-radius-card: 12px;
    --border-radius-elements: 8px;
 
    --font-family-primary: 'Open Sans', 'Roboto', Arial, sans-serif;
}
 
/* General Body Styles */
body {
    font-family: var(--font-family-primary);
    margin: 0;
    padding: 0;
    background-color: var(--siemens-light-gray);
    color: var(--siemens-dark-gray);
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}
 
/* Header */
header {
    background-color: var(--siemens-corporate-blue);
    color: var(--siemens-white);
    padding: 1.8rem 1rem;
    text-align: center;
    box-shadow: var(--shadow-medium);
}
 
header h1 {
    margin: 0;
    font-size: 2.8rem;
    font-weight: 700;
}
 
header .tagline {
    font-size: 1.1rem;
    opacity: 0.9;
    margin-top: 0.5rem;
}
 
/* Main Container */
.container {
    max-width: 960px;
    margin: 2.5rem auto;
    padding: 1.2rem;
    flex-grow: 1;
}
 
/* Card Styles */
.card {
    background-color: var(--siemens-white);
    padding: 2.5rem;
    margin-bottom: 2rem;
    border-radius: var(--border-radius-card);
    box-shadow: var(--shadow-light);
    transition: transform 0.3s ease-in-out;
}
 
.card:hover {
    transform: translateY(-3px);
}
 
.section-title {
    color: var(--siemens-corporate-blue);
    margin-top: 0;
    margin-bottom: 2rem;
    font-size: 2.2rem;
    font-weight: 600;
    border-bottom: 3px solid var(--siemens-accent-turquoise);
    padding-bottom: 0.8rem;
}
 
/* Drag and Drop Area */
.drag-drop-area {
    border: 3px dashed var(--siemens-medium-gray);
    border-radius: var(--border-radius-card);
    padding: 4rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background-color: rgba(0, 153, 153, 0.03); /* Very light tint of turquoise */
}
 
.drag-drop-area:hover,
.drag-drop-area.drag-over {
    border-color: var(--siemens-accent-turquoise);
    background-color: rgba(0, 153, 153, 0.08);
}
 
.drag-drop-area p {
    margin-bottom: 1.5rem;
    color: var(--siemens-dark-gray);
    font-size: 1.2rem;
    font-weight: 500;
}
 
/* Buttons */
.btn {
    padding: 1rem 2rem;
    border: none;
    border-radius: var(--border-radius-elements);
    cursor: pointer;
    font-size: 1.1rem;
    font-weight: 600;
    transition: background-color 0.3s ease, transform 0.2s ease, box-shadow 0.3s ease;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}
 
.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}
 
.btn-primary {
    background-color: var(--siemens-accent-turquoise);
    color: var(--siemens-white);
    box-shadow: 0 4px 8px rgba(0, 153, 153, 0.3);
}
 
.btn-primary:not(:disabled):hover {
    background-color: #007a7a;
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(0, 153, 153, 0.4);
}
 
.btn-cta {
    background-color: var(--siemens-corporate-blue);
    color: var(--siemens-white);
    box-shadow: 0 4px 8px rgba(0, 51, 102, 0.3);
}
 
.btn-cta:not(:disabled):hover {
    background-color: #002244;
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(0, 51, 102, 0.4);
}
 
.btn-secondary {
    background-color: var(--siemens-medium-gray);
    color: var(--siemens-dark-gray);
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}
 
.btn-secondary:not(:disabled):hover {
    background-color: #b3b3b3;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}
 
.button-group {
    display: flex;
    gap: 1.5rem;
    margin-top: 2rem;
    flex-wrap: wrap;
    justify-content: center;
}
 
/* File Info */
.file-info {
    margin-top: 1rem;
    font-style: italic;
    color: var(--siemens-dark-gray);
    text-align: center;
}
 
/* Input Group */
.input-group {
    margin-bottom: 1.5rem;
}
 
.input-group label {
    display: block;
    margin-bottom: 0.8rem;
    font-weight: 600;
    color: var(--siemens-dark-gray);
    font-size: 1.1rem;
}
 
.input-group select,
.input-group input[type="range"] {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid var(--siemens-medium-gray);
    border-radius: var(--border-radius-elements);
    font-size: 1rem;
    box-sizing: border-box; /* Include padding in width */
    background-color: var(--siemens-white);
    color: var(--siemens-dark-gray);
}
 
.input-group input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    height: 10px;
    background: var(--siemens-medium-gray);
    outline: none;
    opacity: 0.9;
    transition: opacity .2s;
}
 
.input-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--siemens-accent-turquoise);
    cursor: pointer;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
}
 
.input-group input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--siemens-accent-turquoise);
    cursor: pointer;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
}
 
.checkbox-group {
    display: flex;
    align-items: center;
    gap: 0.8rem;
    margin-top: 1.5rem;
}
 
.checkbox-group input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--siemens-accent-turquoise); /* For modern browsers */
    border: 1px solid var(--siemens-medium-gray);
    border-radius: 4px;
}
 
.checkbox-group label {
    margin-bottom: 0; /* Override default label margin */
    font-weight: normal;
}
 
 
/* Result Section */
.file-comparison {
    text-align: center;
    margin-bottom: 2rem;
    font-size: 1.1rem;
    line-height: 1.8;
}
 
.file-comparison p {
    margin: 0.5rem 0;
}
 
.file-comparison span {
    font-weight: bold;
    color: var(--siemens-corporate-blue);
}
 
.result-actions {
    text-align: center;
    margin-top: 1.5rem;
}
 
/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(255, 255, 255, 0.95);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px); /* For Safari */
}
 
.spinner {
    border: 8px solid var(--siemens-light-gray);
    border-top: 8px solid var(--siemens-accent-turquoise);
    border-radius: 50%;
    width: 60px;
    height: 60px;
    animation: spin 1s linear infinite;
    margin-bottom: 2rem;
}
 
@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}
 
.loading-overlay p {
    font-size: 1.5rem;
    color: var(--siemens-corporate-blue);
    font-weight: 600;
    margin-bottom: 1.5rem;
}
 
.progress-bar-container {
    width: 80%;
    max-width: 400px;
    background-color: var(--siemens-medium-gray);
    border-radius: 5px;
    height: 15px;
    overflow: hidden;
    margin-bottom: 1rem;
}
 
.progress-bar {
    height: 100%;
    background-color: var(--siemens-accent-turquoise);
    width: 0%;
    border-radius: 5px;
    transition: width 0.3s ease-out;
}
 
.progress-text {
    font-size: 1.1rem;
    color: var(--siemens-dark-gray);
}
 
/* Notifications */
#notification-container {
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 1001;
    display: flex;
    flex-direction: column-reverse; /* New notifications appear on top */
    gap: 12px;
}
 
.notification {
    padding: 1.2rem 1.8rem;
    border-radius: var(--border-radius-elements);
    color: var(--siemens-white);
    font-weight: bold;
    box-shadow: 0 6px 12px rgba(0,0,0,0.2);
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInSlideUp 0.5s forwards, fadeOut 0.5s forwards 4.5s; /* Fade in, then fade out after 4.5s (total 5s display) */
}
 
.notification.success {
    background-color: #28a745; /* Green */
}
 
.notification.error {
    background-color: #dc3545; /* Red */
}
 
@keyframes fadeInSlideUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}
 
@keyframes fadeOut {
    from { opacity: 1; }
    to { opacity: 0; }
}
 
/* Utility Class */
.hidden {
    display: none !important;
}
 
/* Footer */
footer {
    text-align: center;
    padding: 1.8rem 1rem;
    background-color: var(--siemens-corporate-blue);
    color: var(--siemens-white);
    margin-top: 3rem;
    box-shadow: 0 -4px 10px rgba(0,0,0,0.1);
}
 
/* Mobile Responsiveness */
@media (max-width: 768px) {
    header h1 {
        font-size: 2.2rem;
    }
    header .tagline {
        font-size: 1rem;
    }
 
    .container {
        margin: 1.5rem auto;
        padding: 0.8rem;
    }
 
    .card {
        padding: 1.5rem;
        margin-bottom: 1.5rem;
    }
 
    .section-title {
        font-size: 1.8rem;
        margin-bottom: 1.5rem;
    }
 
    .drag-drop-area {
        padding: 3rem 1.5rem;
    }
 
    .drag-drop-area p {
        font-size: 1.1rem;
    }
 
    .btn {
        padding: 0.8rem 1.2rem;
        font-size: 1rem;
        width: 100%; /* Full width buttons on small screens */
    }
 
    .button-group {
        flex-direction: column;
        gap: 1rem;
    }
 
    .file-info {
        font-size: 0.9rem;
    }
 
    .input-group label {
        font-size: 1rem;
    }
 
    .loading-overlay p {
        font-size: 1.2rem;
    }
 
    .spinner {
        width: 50px;
        height: 50px;
        border-width: 6px;
    }
 
    .progress-bar-container {
        width: 90%;
    }
 
    #notification-container {
        bottom: 10px;
        right: 10px;
        left: 10px; /* Make notifications full width on small screens */
    }
 
    .notification {
        padding: 1rem 1.2rem;
        font-size: 0.9rem;
    }
}