/* Base Styles - CSS Variables and Common Components */
:root {
    --primary-color: #0f3460;
    --secondary-color: #16213e;
    --accent-color: #e94560;
    --success-color: #16c79a;
    --warning-color: #f5a623;
    --danger-color: #e94560;
    --text-primary: #333;
    --text-secondary: #666;
    --bg-primary: #f5f5f5;
    --bg-secondary: #fff;
    --border-color: #ddd;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.15);
    --radius: 8px;
    --radius-lg: 12px;
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

h1 { font-size: 2rem; }
h2 { font-size: 1.75rem; }
h3 { font-size: 1.5rem; }

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--accent-color);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    border: none;
    border-radius: var(--radius);
    cursor: pointer;
    transition: var(--transition);
}

.btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.btn-primary { background-color: var(--primary-color); color: white; }
.btn-secondary { background-color: var(--secondary-color); color: white; }
.btn-success { background-color: var(--success-color); color: white; }
.btn-warning { background-color: var(--warning-color); color: white; }
.btn-danger { background-color: var(--danger-color); color: white; }
.btn-sm { padding: 0.5rem 1rem; font-size: 0.875rem; }
.btn-block { width: 100%; }
.btn-icon { padding: 0.5rem; width: 40px; height: 40px; }

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-group input {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius);
    background-color: var(--bg-secondary);
    transition: var(--transition);
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(15, 52, 96, 0.1);
}

.error-message {
    display: block;
    margin-top: 0.5rem;
    color: var(--danger-color);
    font-size: 0.875rem;
    min-height: 1.25rem;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 1rem;
}

.modal-content {
    background-color: var(--bg-secondary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    max-width: 500px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h2 {
    margin: 0;
    font-size: 1.5rem;
}

.modal-body {
    padding: 1.5rem;
}

.modal-footer {
    padding: 1.5rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    gap: 1rem;
    justify-content: flex-end;
}

/* Theme Toggle */
.btn-theme-toggle {
    background: none;
    border: 2px solid var(--border-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    font-size: 1.25rem;
    transition: var(--transition);
}

.btn-theme-toggle:hover {
    border-color: var(--primary-color);
    transform: rotate(180deg);
}

/* Utility Classes */
.text-center { text-align: center; }
.text-right { text-align: right; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }