/* Common styles and variables */
:root {
    --bg-page: #f5f7fa;
    --text-main: #333;
    --text-muted: #666;
    --primary: #667eea;
    --primary-2: #764ba2;
    --card-bg: #ffffff;
    --border: #e0e0e0;
    --shadow-lg: 0 10px 30px rgba(102, 126, 234, 0.3);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg-page);
    min-height: 100vh;
    padding: 20px;
    color: var(--text-main);
}

.container { max-width: 1400px; margin: 0 auto; }

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    font-size: 1em;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}
.btn-primary { background: linear-gradient(135deg, var(--primary) 0%, var(--primary-2) 100%); color: #fff; }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 5px 15px rgba(102,126,234,0.4); }
.btn-secondary { background: #e0e0e0; color: #333; }
.btn-secondary:hover { background: #d0d0d0; }

.error-message { background: #ffebee; color: #c62828; padding: 15px; border-radius: 8px; margin-bottom: 20px; border: 1px solid #ffcdd2; }
.loading { text-align: center; padding: 40px; color: var(--primary); font-size: 1.2em; }
.empty { text-align: center; padding: 60px; color: #999; }

/* Responsive helpers */
.hidden-sm { display: block; }
@media (max-width: 900px) {
    .hidden-sm { display: none; }
    .container { padding: 0 6px; }
}