:root {
    /* Core Variables - Default (Light) */
    --bg-primary: #f8f9fa;
    --bg-secondary: #ffffff;
    --bg-card: #ffffff;
    --text-primary: #212529;
    --text-secondary: #6c757d;
    --accent-color: #0d6efd;
    --border-color: #dee2e6;
    
    --status-validated: #198754;
    --status-draft: #6c757d;
    --status-warning: #ffc107;
}

[data-theme="dark"] {
    --bg-primary: #212529;
    --bg-secondary: #343a40;
    --bg-card: #2c3035;
    --text-primary: #f8f9fa;
    --text-secondary: #adb5bd;
    --accent-color: #375a7f;
    --border-color: #495057;
}

[data-theme="spring"] {
    --bg-primary: #e8f5e9;
    --bg-secondary: #ffffff;
    --bg-card: #f1f8e9;
    --text-primary: #1b5e20;
    --text-secondary: #388e3c;
    --accent-color: #4caf50;
    --border-color: #c8e6c9;
}

[data-theme="summer"] {
    --bg-primary: #fffde7;
    --bg-secondary: #ffffff;
    --bg-card: #fff9c4;
    --text-primary: #f57f17;
    --text-secondary: #fbc02d;
    --accent-color: #ffca28;
    --border-color: #fff176;
}

[data-theme="autumn"] {
    --bg-primary: #fff3e0;
    --bg-secondary: #ffffff;
    --bg-card: #ffe0b2;
    --text-primary: #e65100;
    --text-secondary: #f57c00;
    --accent-color: #ff9800;
    --border-color: #ffcc80;
}

[data-theme="winter"] {
    --bg-primary: #e3f2fd;
    --bg-secondary: #ffffff;
    --bg-card: #e1f5fe;
    --text-primary: #01579b;
    --text-secondary: #0288d1;
    --accent-color: #03a9f4;
    --border-color: #b3e5fc;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    transition: background-color 0.3s, color 0.3s;
    margin: 0;
    padding: 0;
}

.btn-secondary {
    background-color: var(--text-secondary);
    color: #fff;
}

.btn-info {
    background-color: #17a2b8;
    color: #fff;
}

.theme-switcher {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    padding: 10px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    z-index: 1000;
}

.btn-theme {
    border: none;
    background: transparent;
    cursor: pointer;
    font-size: 1.2rem;
    padding: 5px;
    border-radius: 4px;
    transition: transform 0.2s;
}

.btn-theme:hover {
    transform: scale(1.1);
    background-color: var(--border-color);
}