/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Header Styles */
.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 1rem 0;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
    margin-bottom: 2rem;
}

.header h1 {
    text-align: center;
    color: #4a5568;
    font-size: 2.5rem;
    font-weight: 700;
}

.header .subtitle {
    text-align: center;
    color: #718096;
    margin-top: 0.5rem;
}

/* Card Styles */
.card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    margin-bottom: 2rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15);
}

/* Form Styles */
.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #4a5568;
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
    background: rgba(255, 255, 255, 0.9);
}

.form-control:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

textarea.form-control {
    resize: vertical;
    min-height: 100px;
}

/* Button Styles */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    margin: 0.25rem;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.3);
}

.btn-success {
    background: linear-gradient(135deg, #48bb78 0%, #38a169 100%);
    color: white;
}

.btn-success:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(72, 187, 120, 0.3);
}

.btn-danger {
    background: linear-gradient(135deg, #f56565 0%, #e53e3e 100%);
    color: white;
}

.btn-danger:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(245, 101, 101, 0.3);
}

.btn-secondary {
    background: linear-gradient(135deg, #a0aec0 0%, #718096 100%);
    color: white;
}

.btn-secondary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(160, 174, 192, 0.3);
}

/* Table Styles */
.table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
    background: rgba(255, 255, 255, 0.9);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.table th,
.table td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid #e2e8f0;
}

.table th {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    font-weight: 600;
}

.table tr:hover {
    background: rgba(102, 126, 234, 0.05);
}

/* Alert Styles */
.alert {
    padding: 1rem 1.5rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    font-weight: 500;
}

.alert-success {
    background: rgba(72, 187, 120, 0.1);
    border: 1px solid rgba(72, 187, 120, 0.3);
    color: #2f855a;
}

.alert-error {
    background: rgba(245, 101, 101, 0.1);
    border: 1px solid rgba(245, 101, 101, 0.3);
    color: #c53030;
}

.alert-info {
    background: rgba(102, 126, 234, 0.1);
    border: 1px solid rgba(102, 126, 234, 0.3);
    color: #3182ce;
}

/* Login Form Styles */
.login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 2rem;
}

.login-card {
    width: 100%;
    max-width: 400px;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 15px;
    padding: 3rem;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
}

.login-card h2 {
    text-align: center;
    margin-bottom: 2rem;
    color: #4a5568;
    font-size: 2rem;
}

/* File Upload Styles */
.file-upload {
    position: relative;
    display: inline-block;
    width: 100%;
}

.file-upload input[type=file] {
    position: absolute;
    opacity: 0;
    width: 100%;
    height: 100%;
    cursor: pointer;
}

.file-upload-label {
    display: block;
    padding: 2rem;
    border: 2px dashed #667eea;
    border-radius: 8px;
    text-align: center;
    background: rgba(102, 126, 234, 0.05);
    cursor: pointer;
    transition: all 0.3s ease;
}

.file-upload-label:hover {
    background: rgba(102, 126, 234, 0.1);
    border-color: #764ba2;
}

/* Download Item Styles */
.download-item {
    display: flex;
    align-items: center;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.9);
    border-radius: 12px;
    margin-bottom: 1rem;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.download-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.15);
}

.download-icon {
    font-size: 2.5rem;
    margin-right: 1.5rem;
}

.download-info {
    flex: 1;
}

.download-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: #4a5568;
    margin-bottom: 0.5rem;
}

.download-description {
    color: #718096;
    margin-bottom: 0.5rem;
}

.download-meta {
    font-size: 0.875rem;
    color: #a0aec0;
}

.download-actions {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

/* Search and Filter Styles */
.search-filter {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.search-filter .form-control {
    flex: 1;
    min-width: 200px;
}

/* Navigation Styles */
.nav {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 1rem 0;
    margin-bottom: 2rem;
    border-radius: 12px;
}

.nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 2rem;
}

.nav a {
    text-decoration: none;
    color: #4a5568;
    font-weight: 600;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    transition: all 0.3s ease;
}

.nav a:hover,
.nav a.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }
    
    .header h1 {
        font-size: 2rem;
    }
    
    .card {
        padding: 1.5rem;
    }
    
    .search-filter {
        flex-direction: column;
    }
    
    .download-item {
        flex-direction: column;
        text-align: center;
    }
    
    .download-icon {
        margin-right: 0;
        margin-bottom: 1rem;
    }
    
    .download-actions {
        flex-direction: row;
        justify-content: center;
        margin-top: 1rem;
    }
    
    .table {
        font-size: 0.875rem;
    }
    
    .table th,
    .table td {
        padding: 8px 12px;
    }
}

/* Utility Classes */
.text-center {
    text-align: center;
}

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

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.d-flex {
    display: flex;
}

.justify-content-between {
    justify-content: space-between;
}

.align-items-center {
    align-items: center;
}

.w-100 {
    width: 100%;
}