:root {
    --bg-color: #f4f7f9;
    --card-bg: #ffffff;
    --primary-text: #2c3e50;
    --secondary-text: #7f8c8d;
    --border-color: #e0e5ea;
    --shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    --status-en-cours: #f39c12;
    --status-acheve: #3498db;
    --status-comprise: #2ecc71;
}

body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--bg-color);
    color: var(--primary-text);
    margin: 0;
    padding: 20px;
    line-height: 1.6;
}

header {
    background: var(--card-bg);
    padding: 20px 30px;
    border-radius: 12px;
    box-shadow: var(--shadow);
    margin-bottom: 30px;
    text-align: center;
}

header h1 {
    margin: 0;
    color: var(--primary-text);
}

.settings {
    margin-top: 15px;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.settings input, .settings button {
    padding: 10px 15px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    font-size: 14px;
}

.settings button {
    background-color: var(--status-acheve);
    color: white;
    cursor: pointer;
    border: none;
    transition: background-color 0.3s;
}

.settings button:hover {
    background-color: #2980b9;
}

#courses-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 25px;
}

.course-card {
    background-color: var(--card-bg);
    border-radius: 12px;
    box-shadow: var(--shadow);
    padding: 25px;
    display: flex;
    flex-direction: column;
}

.course-card h2 {
    margin-top: 0;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 10px;
}

.exam-info {
    background-color: var(--bg-color);
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 20px;
}

.exam-info input[type="date"] {
    width: 100%;
    padding: 8px;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    margin-bottom: 10px;
}

.countdown {
    font-weight: 600;
    font-size: 1.1em;
}

.add-series-form {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

.add-series-form input {
    flex-grow: 1;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
}

.add-series-form button {
    padding: 10px 15px;
    border: none;
    background-color: var(--status-comprise);
    color: white;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.add-series-form button:hover {
    background-color: #27ae60;
}

.series-list {
    list-style-type: none;
    padding: 0;
    margin: 0;
}

.series-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 15px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    margin-bottom: 10px;
    transition: box-shadow 0.3s;
}

.series-item:hover {
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

.series-item a {
    text-decoration: none;
    color: var(--primary-text);
    font-weight: 600;
}

.series-item select {
    padding: 5px 8px;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    font-family: 'Poppins', sans-serif;
}

.status-indicator {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    margin-right: 12px;
    flex-shrink: 0;
}

.status-en_cours { background-color: var(--status-en-cours); }
.status-acheve { background-color: var(--status-acheve); }
.status-comprise { background-color: var(--status-comprise); }

footer {
    text-align: center;
    margin-top: 40px;
    color: var(--secondary-text);
    font-size: 0.9em;
}