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

:root {
    --bg-primary: #24272b;
    --bg-secondary: #2e3238;
    --bg-tertiary: #383d45;
    --bg-elevated: #181b1f;
    --border-subtle: #4a5059;
    --text-primary: #f3f4f6;
    --text-secondary: #c4cad3;
    --text-muted: #98a2b3;
    --link-surface: #3a4048;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(180deg, #2b2f34 0%, #1d2024 100%);
    color: var(--text-primary);
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Navigation Bar */
.navbar {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 0;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-brand .logo {
    font-size: 1.8em;
    font-weight: bold;
    color: white;
    text-decoration: none;
    transition: transform 0.3s ease;
}

.nav-brand .logo:hover {
    transform: scale(1.05);
}

.nav-menu {
    list-style: none;
    display: flex;
    gap: 30px;
    align-items: center;
}

.nav-link {
    color: white;
    text-decoration: none;
    font-weight: 500;
    padding: 8px 16px;
    border-radius: 5px;
    transition: background 0.3s ease, transform 0.2s ease;
}

.nav-link:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

/* Footer */
.footer {
    background: var(--bg-elevated);
    color: var(--text-secondary);
    text-align: center;
    padding: 20px;
    margin-top: auto;
    font-size: 0.9em;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    flex: 1;
}

h1 {
    color: var(--text-primary);
    margin-bottom: 20px;
}

h2 {
    color: var(--text-primary);
    margin-bottom: 15px;
}

form {
    background: var(--bg-secondary);
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 16px 36px rgba(0, 0, 0, 0.28);
    margin-bottom: 20px;
    border: 1px solid rgba(255, 255, 255, 0.06);
}

form p {
    margin-bottom: 15px;
}

label {
    display: block;
    font-weight: bold;
    margin-bottom: 5px;
    color: var(--text-secondary);
}

input[type="text"],
input[type="number"],
select {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-subtle);
    border-radius: 4px;
    font-size: 14px;
    color: var(--text-primary);
    background: var(--bg-tertiary);
}

input[type="text"]:focus,
input[type="number"]:focus,
select:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.18);
}

input::placeholder {
    color: var(--text-muted);
}

button {
    padding: 10px 20px;
    background: #667eea;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-weight: bold;
    transition: background 0.3s;
}

button:hover {
    background: #764ba2;
}

button:active {
    transform: scale(0.99);
}

.nav-links {
    margin-bottom: 20px;
}

.nav-links a {
    display: inline-block;
    padding: 8px 15px;
    background: var(--link-surface);
    color: var(--text-primary);
    text-decoration: none;
    border-radius: 4px;
    transition: background 0.3s;
    margin-right: 10px;
}

.nav-links a:hover {
    background: var(--bg-tertiary);
}

table {
    width: 100%;
    background: var(--bg-secondary);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 16px 36px rgba(0, 0, 0, 0.24);
    border: 1px solid rgba(255, 255, 255, 0.06);
}

table thead {
    background: #667eea;
    color: white;
}

table th,
table td {
    padding: 12px 15px;
    text-align: left;
}

table tbody tr:nth-child(even) {
    background: rgba(0, 0, 0, 0.08);
}

table tbody tr:hover {
    background: rgba(0, 0, 0, 0.14);
}

.error {
    background: #f8d7da;
    color: #721c24;
    padding: 12px;
    border-radius: 4px;
    margin-bottom: 20px;
    border: 1px solid #f5c6cb;
}

.success {
    background: #d4edda;
    color: #155724;
    padding: 12px;
    border-radius: 4px;
    margin-bottom: 20px;
    border: 1px solid #c3e6cb;
}

.info {
    background: #d1ecf1;
    color: #0c5460;
    padding: 12px;
    border-radius: 4px;
    margin-bottom: 20px;
    border: 1px solid #bee5eb;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        gap: 15px;
        font-size: 0.9em;
    }
    
    .nav-brand .logo {
        font-size: 1.4em;
    }
    
    .nav-container {
        height: auto;
        padding: 15px 20px;
        flex-wrap: wrap;
    }
    
    .navbar {
        position: relative;
    }
}

@media (max-width: 480px) {
    .nav-menu {
        gap: 10px;
        font-size: 0.85em;
    }
    
    .nav-brand .logo {
        font-size: 1.2em;
    }
    
    .nav-link {
        padding: 6px 12px;
    }
}