.header-bg {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    position: relative;
    overflow: hidden;
    background: url("https://sv.uhl.edu.vn/FileManager/Upload/images/bg_header.png")
        no-repeat center center;
    background-size: cover;
}

.header-bg::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="%23dee2e6" stroke-width="0.5"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
}

.logo {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, #ffffff, #e3e3e3);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 2rem;
    position: relative;
}

.logo img {
    height: 50px;
}

.navbar-custom {
    background: linear-gradient(135deg, #4c6ef5, #364fc7);
}

.navbar-custom .nav-link {
    color: white !important;
    font-weight: 500;
    padding: 0.75rem 1rem;
    border-radius: 5px;
    margin: 0 2px;
    transition: all 0.3s;
}

.navbar-custom .nav-link:hover {
    background: rgba(255, 255, 255, 0.1);
}

.section-header {
    background: linear-gradient(135deg, #f59e0b, #d97706);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 5px 5px 0 0;
    font-weight: bold;
}

.section-header.blue {
    background: linear-gradient(135deg, #3b82f6, #2563eb);
}

.section-header.brown {
    background: linear-gradient(135deg, #92400e, #78350f);
}

.section-header.green {
    background: linear-gradient(135deg, #059669, #047857);
}

.news-item {
    border-left: 3px solid #3b82f6;
    padding-left: 1rem;
    margin-bottom: 1rem;
}

.news-date {
    color: #6b7280;
    font-size: 0.875rem;
}

.university-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, #0ea5e9, #0284c7);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.2rem;
    margin-right: 1rem;
    flex-shrink: 0;
}

.footer {
    background: linear-gradient(135deg, #3b82f6, #1d4ed8);
    color: white;
    padding: 1.5rem 0 1rem 0;
    margin-top: 2rem;
}

.footer h6 {
    color: #fff;
    font-weight: bold;
    margin-bottom: 0.75rem;
    font-size: 0.95rem;
}

.footer-contact {
    background: rgba(255, 255, 255, 0.1);
    padding: 0.75rem;
    border-radius: 6px;
    margin-bottom: 1rem;
    font-size: 0.875rem;
}

.footer-divider {
    height: 1px;
    background: linear-gradient(90deg, transparent, #fbbf24, transparent);
    margin: 1rem 0;
}

.university-info {
    background: rgba(255, 255, 255, 0.1);
    padding: 0.75rem;
    border-radius: 6px;
    border-left: 3px solid #fbbf24;
    font-size: 0.875rem;
}

.footer-support {
    background: rgba(255, 255, 255, 0.08);
    padding: 0.5rem;
    border-radius: 6px;
    text-align: center;
    font-size: 0.8rem;
}

.footer-icon {
    color: #fff;
    margin-right: 0.25rem;
}

/* File Upload Styles */
.upload-area {
    border: 2px dashed #3b82f6;
    border-radius: 10px;
    padding: 2rem;
    text-align: center;
    background: linear-gradient(135deg, #f8fafc, #e2e8f0);
    transition: all 0.3s;
    cursor: pointer;
}

.upload-area:hover {
    border-color: #1d4ed8;
    background: linear-gradient(135deg, #e0f2fe, #bae6fd);
}

.upload-area.dragover {
    border-color: #059669;
    background: linear-gradient(135deg, #d1fae5, #a7f3d0);
}

.file-input {
    display: none;
}

.upload-icon {
    font-size: 3rem;
    color: #3b82f6;
    margin-bottom: 1rem;
}

.file-list {
    max-height: 300px;
    overflow-y: auto;
}

.file-item {
    background: #f8fafc;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    padding: 1rem;
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.file-info {
    display: flex;
    align-items: center;
}

.file-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, #3b82f6, #1d4ed8);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    margin-right: 1rem;
}

.progress-bar {
    height: 4px;
    background: #e2e8f0;
    border-radius: 2px;
    overflow: hidden;
    margin-top: 0.5rem;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #10b981, #059669);
    transition: width 0.3s;
}

.hero-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 4rem 0;
    position: relative;
    overflow: hidden;
}
.hero-section::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1000 1000"><polygon fill="%23ffffff" fill-opacity="0.1" points="0,1000 1000,0 1000,1000"/></svg>');
}
.feature-card {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s, box-shadow 0.3s;
    border: none;
    height: 100%;
}
.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}
.feature-icon {
    width: 70px;
    height: 70px;
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    font-size: 2rem;
    color: white;
}
.stats-card {
    background: linear-gradient(135deg, #ff6b6b, #ee5a52);
    color: white;
    border-radius: 15px;
    padding: 2rem;
    text-align: center;
    margin-bottom: 1rem;
}
.stats-card.blue {
    background: linear-gradient(135deg, #4facfe, #00f2fe);
}
.stats-card.green {
    background: linear-gradient(135deg, #43e97b, #38f9d7);
}
.stats-card.orange {
    background: linear-gradient(135deg, #fa709a, #fee140);
}
.quick-action-btn {
    background: linear-gradient(135deg, #667eea, #764ba2);
    border: none;
    color: white;
    padding: 1rem 2rem;
    border-radius: 10px;
    font-weight: 600;
    transition: all 0.3s;
    margin: 0.5rem;
}
.quick-action-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
    color: white;
}
.timeline-item {
    background: white;
    border-radius: 10px;
    padding: 1.5rem;
    margin-bottom: 1rem;
    border-left: 4px solid #667eea;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}
.login-container {
    min-height: 100vh;
    background: linear-gradient(135deg, #377ef4 0%, #2563eb 100%);
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
}
.login-container::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1000 1000"><polygon fill="%23ffffff" fill-opacity="0.1" points="0,1000 1000,0 1000,1000"/></svg>');
}
.login-card {
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15);
    overflow: hidden;
    position: relative;
    z-index: 1;
}
.login-header {
    background: linear-gradient(135deg, #377ef4, #2563eb);
    color: white;
    padding: 2rem;
    text-align: center;
}
.login-form {
    padding: 2rem;
}
.form-floating label {
    color: #6c757d;
}
.form-floating .form-control:focus ~ label {
    color: #377ef4;
}
.form-floating .form-control:focus {
    border-color: #377ef4;
    box-shadow: 0 0 0 0.2rem rgba(55, 126, 244, 0.25);
}
.login-btn {
    background: linear-gradient(135deg, #377ef4, #2563eb);
    border: none;
    padding: 0.75rem;
    font-weight: 600;
    transition: all 0.3s;
}
.login-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(55, 126, 244, 0.3);
}
.role-selector {
    background: #f8f9fa;
    border-radius: 10px;
    padding: 1rem;
    margin-bottom: 1.5rem;
}
.role-option {
    background: white;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    padding: 0.75rem;
    margin: 0.25rem;
    cursor: pointer;
    transition: all 0.3s;
    text-align: center;
}
.role-option:hover {
    border-color: #377ef4;
    background: #f0f7ff;
}
.role-option.active {
    border-color: #377ef4;
    background: #377ef4;
    color: white;
}
.university-logo {
    width: 60px;
    height: 60px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
}
.university-logo img {
    max-width: 80%;
    max-height: 80%;
}