:root {
    --primary-color: #2c3e50;
    --secondary-color: #34495e;
    --accent-color: #3498db;
    --accent-hover: #2980b9;
    --background-color: #f4f6f8;
    --card-bg: #ffffff;
    --text-color: #333333;
    --border-color: #e0e0e0;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    padding: 0;
    line-height: 1.6;
}

/* Layout */
.app-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header */
header {
    background-color: var(--primary-color);
    color: white;
    padding: 1rem 2rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

header h1 {
    margin: 0;
    font-size: 1.5rem;
    font-weight: 600;
}

header nav {
    margin-top: 1rem;
}

header nav a {
    color: #bdc3c7;
    text-decoration: none;
    margin-right: 1.5rem;
    font-weight: 500;
    transition: color 0.2s;
}

header nav a:hover, header nav a.active {
    color: white;
}

/* Main Content */
main {
    flex: 1;
    padding: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

/* Cards */
.card {
    background: var(--card-bg);
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    padding: 2rem;
    margin-bottom: 2rem;
}

.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.action-card {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    text-align: center;
    transition: transform 0.2s, box-shadow 0.2s;
}

.action-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 12px rgba(0,0,0,0.1);
    border-color: var(--accent-color);
}

.action-card h3 {
    color: var(--primary-color);
    margin-top: 0;
}

.btn {
    display: inline-block;
    background-color: var(--accent-color);
    color: white;
    padding: 0.6rem 1.2rem;
    border-radius: 4px;
    text-decoration: none;
    font-weight: 500;
    border: none;
    cursor: pointer;
    transition: background-color 0.2s;
}

.btn:hover {
    background-color: var(--accent-hover);
}

.btn-secondary {
    background-color: transparent;
    color: var(--accent-color);
    border: 1px solid var(--accent-color);
}

.btn-secondary:hover {
    background-color: var(--accent-color);
    color: white;
}

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

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--secondary-color);
}

input[type="text"],
input[type="number"],
select {
    width: 100%;
    padding: 0.6rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 1rem;
}

input:focus, select:focus {
    border-color: var(--accent-color);
    outline: none;
    box-shadow: 0 0 0 2px rgba(52, 152, 219, 0.2);
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

/* Footer */
footer {
    text-align: center;
    padding: 1.5rem;
    background-color: var(--primary-color);
    color: #7f8c8d;
    font-size: 0.9rem;
}