:root {
    /* Default Light Theme with Red Accent */
    --primary-color: #D95550;
    --bg-color: #FFFFFF;
    --container-bg-color: #FDF5F6;
    --text-color: #333333;
    --subtle-text-color: #555555;
    --border-color: #DDDDDD;
}
body.dark-mode {
    /* Dark Theme Variables */
    --bg-color: #121212;
    --container-bg-color: #1E1E1E;
    --text-color: #E0E0E0;
    --subtle-text-color: #AAAAAA;
    --border-color: #444444;
}
body { background-color: var(--bg-color); font-family: Arial, sans-serif; transition: background-color 0.3s ease; }
.pomodoro-container { max-width: 480px; margin: 40px auto; padding: 20px; background-color: var(--container-bg-color); border-radius: 10px; box-shadow: 0 5px 15px rgba(0,0,0,0.1); text-align: center; position: relative; transition: background-color 0.3s ease; }
.timer-modes .mode-btn { border: none; background: none; padding: 10px 15px; margin: 0 5px; cursor: pointer; font-size: 16px; border-radius: 5px; color: var(--text-color); transition: color 0.3s ease, background-color 0.3s ease; }
.timer-modes .mode-btn.active { background-color: var(--primary-color); color: white; }
.timer-display h1 { font-size: 100px; font-weight: bold; margin: 20px 0; color: var(--primary-color); transition: color 0.3s ease; }
.timer-controls .control-btn, .save-btn { background-color: var(--primary-color); color: white; border: none; padding: 15px 40px; font-size: 22px; cursor: pointer; border-radius: 5px; box-shadow: 0 4px 8px rgba(0,0,0,0.2); transition: all 0.2s ease; }
.save-btn { font-size: 16px; padding: 10px 20px; }
.timer-controls .control-btn:hover { transform: translateY(-2px); }
.session-info { font-size: 16px; color: var(--subtle-text-color); margin-top: 20px; margin-bottom: 0; transition: color 0.3s ease; }
.task-container { margin-top: 30px; text-align: left; }
.task-container h2 { border-bottom: 1px solid var(--border-color); padding-bottom: 10px; margin-bottom: 15px; color: var(--text-color); transition: color 0.3s ease, border-color 0.3s ease; }
#task-input { width: calc(100% - 100px); padding: 10px; border: 1px solid var(--border-color); border-radius: 5px; background-color: var(--bg-color); color: var(--text-color); transition: color 0.3s ease, background-color 0.3s ease, border-color 0.3s ease; }
#add-task-btn { padding: 10px 15px; border: none; background-color: var(--primary-color); color: white; border-radius: 5px; cursor: pointer; transition: background-color 0.3s ease; }
.task-item { display: flex; justify-content: space-between; align-items: center; background-color: var(--bg-color); padding: 10px; border-bottom: 1px solid var(--border-color); border-radius: 5px; margin-bottom: 8px; transition: color 0.3s ease, background-color 0.3s ease, border-color 0.3s ease; }
.task-item span { color: var(--text-color); }
.task-item .delete-btn { border: none; background: none; cursor: pointer; color: #ccc; font-size: 18px; font-weight: bold; }
.task-item .delete-btn:hover { color: var(--primary-color); }
.settings-icon { position: absolute; top: 20px; right: 20px; background: none; border: none; cursor: pointer; color: var(--subtle-text-color); transition: color 0.3s ease; }
.settings-icon:hover { color: var(--primary-color); }
.modal-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background-color: rgba(0, 0, 0, 0.5); display: flex; justify-content: center; align-items: center; z-index: 1000; }
.modal-overlay.hidden { display: none; }
.modal-content { background-color: var(--bg-color); padding: 0; border-radius: 8px; width: 90%; max-width: 500px; transition: background-color 0.3s ease; }
.modal-header, .modal-body, .modal-footer { padding: 20px; transition: background-color 0.3s ease; }
.modal-header { padding-bottom: 10px; border-bottom: 1px solid var(--border-color); display: flex; justify-content: space-between; align-items: center; }
.modal-header h2 { margin: 0; color: var(--text-color); }
.close-btn { background: none; border: none; font-size: 24px; cursor: pointer; color: var(--subtle-text-color); }
.modal-footer { background-color: var(--container-bg-color); border-top: 1px solid var(--border-color); text-align: center; border-bottom-left-radius: 8px; border-bottom-right-radius: 8px; }
.modal-tabs { display: flex; border-bottom: 1px solid var(--border-color); padding: 15px 20px 0 20px; }
.tab-link { border: none; background: none; padding: 10px 15px; cursor: pointer; font-size: 15px; color: var(--subtle-text-color); border-bottom: 2px solid transparent; }
.tab-link.active { color: var(--primary-color); border-bottom: 2px solid var(--primary-color); font-weight: bold; }
.tab-pane { display: none; }
.tab-pane.active { display: block; }
.modal-body h4 { margin-top: 0; margin-bottom: 15px; color: var(--text-color); }
.modal-body hr { border: none; border-top: 1px solid var(--border-color); margin: 20px 0; }
.form-group { display: flex; justify-content: space-between; align-items: center; margin-bottom: 15px; }
.form-group label { font-weight: bold; color: var(--text-color); }
.form-group input[type="number"], .form-group select { width: 120px; padding: 8px; border: 1px solid var(--border-color); border-radius: 5px; background-color: var(--bg-color); color: var(--text-color); }
.switch { position: relative; display: inline-block; width: 50px; height: 28px; }
.switch input { opacity: 0; width: 0; height: 0; }
.slider { position: absolute; cursor: pointer; top: 0; left: 0; right: 0; bottom: 0; background-color: #ccc; transition: .4s; border-radius: 34px; }
.slider:before { position: absolute; content: ""; height: 20px; width: 20px; left: 4px; bottom: 4px; background-color: white; transition: .4s; border-radius: 50%; }
input:checked + .slider { background-color: var(--primary-color); }
input:checked + .slider:before { transform: translateX(22px); }
.form-group input[type="range"] { -webkit-appearance: none; width: 150px; height: 8px; background: #ddd; border-radius: 5px; outline: none; opacity: 0.7; transition: opacity .2s; }
.form-group input[type="range"]:hover { opacity: 1; }
.form-group input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; appearance: none; width: 20px; height: 20px; background: var(--primary-color); cursor: pointer; border-radius: 50%; }
.form-group input[type="range"]::-moz-range-thumb { width: 20px; height: 20px; background: var(--primary-color); cursor: pointer; border-radius: 50%; }
.color-theme-selector { display: flex; gap: 10px; }
.color-btn { width: 30px; height: 30px; border-radius: 50%; border: 2px solid transparent; cursor: pointer; transition: border-color 0.2s ease; }
.color-btn.active { border-color: var(--text-color); }
#color-red { background-color: #D95550; }
#color-blue { background-color: #4A90E2; }
#color-green { background-color: #50E3C2; }