* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

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

.header {
    text-align: center;
    color: white;
    margin-bottom: 30px;
}

.header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.header p {
    font-size: 1.2em;
    opacity: 0.9;
}

.tabs {
    display: flex;
    background: white;
    border-radius: 10px 10px 0 0;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.tab {
    flex: 1;
    padding: 15px 20px;
    background: #f8f9fa;
    border: none;
    cursor: pointer;
    font-size: 16px;
    font-weight: 600;
    transition: all 0.3s ease;
    border-bottom: 3px solid transparent;
}

.tab.active {
    background: white;
    border-bottom-color: #667eea;
    color: #667eea;
}

.tab:hover:not(.active) {
    background: #e9ecef;
}

.content {
    background: white;
    border-radius: 0 0 10px 10px;
    padding: 30px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    min-height: 600px;
}

.section {
    display: none;
}

.section.active {
    display: block;
}

.input-group {
    margin-bottom: 20px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #495057;
}

input, select, textarea {
    width: 100%;
    padding: 12px;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s ease;
}

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

.btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    margin-right: 10px;
    margin-bottom: 10px;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

.hash-result {
    background: #f8f9fa;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    padding: 20px;
    margin: 20px 0;
    font-family: 'Courier New', monospace;
}

.hash-steps {
    background: #fff3cd;
    border: 2px solid #ffeaa7;
    border-radius: 8px;
    padding: 20px;
    margin: 20px 0;
}

.collision-demo {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin: 20px 0;
}

.collision-item {
    background: #fee;
    border: 2px solid #fcc;
    border-radius: 8px;
    padding: 15px;
}

.database-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    background: white;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.database-table th,
.database-table td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid #e9ecef;
}

.database-table th {
    background: #667eea;
    color: white;
    font-weight: 600;
}

.database-table tr:hover {
    background: #f8f9fa;
}

.login-demo {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin: 20px 0;
}

.demo-section {
    background: #f8f9fa;
    border-radius: 8px;
    padding: 20px;
}

.success {
    background: #d4edda;
    border: 2px solid #c3e6cb;
    color: #155724;
}

.error {
    background: #f8d7da;
    border: 2px solid #f5c6cb;
    color: #721c24;
}

.warning {
    background: #fff3cd;
    border: 2px solid #ffeaa7;
    color: #856404;
}

.algorithm-info {
    background: #e3f2fd;
    border: 2px solid #bbdefb;
    border-radius: 8px;
    padding: 15px;
    margin: 15px 0;
}

.hash-comparison {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 15px;
    margin: 20px 0;
}

.hash-item {
    background: #f8f9fa;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    padding: 15px;
}

.hash-item h4 {
    color: #667eea;
    margin-bottom: 10px;
}

.mono {
    font-family: 'Courier New', monospace;
    background: #f1f3f4;
    padding: 4px 8px;
    border-radius: 4px;
    word-break: break-all;
}