.experiment-card {
    background-color: #f0f5ff;
    border-radius: 20px;
    padding: 30px;
    font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    max-width: 800px;
    margin: 20px auto;
    color: #333;
}

.experiment-title {
    color: #2b57d8;
    margin-top: 0;
    margin-bottom: 15px;
    font-size: 24px;
    font-weight: 700;
}

.experiment-description {
    font-size: 16px;
    margin-bottom: 25px;
    color: #444;
}

.formula-box {
    background-color: #1a233a;
    border-radius: 15px;
    padding: 40px 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    margin-bottom: 25px;
}

.formula-text {
    color: #ffffff;
    font-size: 42px;
    font-weight: bold;
    letter-spacing: 2px;
}

.formula-text sub {
    font-size: 0.6em;
    vertical-align: sub;
}

.association-box {
    background-color: #ffffff;
    border-radius: 12px;
    padding: 20px;
    line-height: 1.6;
    font-size: 15px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

.association-box strong {
    color: #333;
}

/*task builder*/
/* Контейнер всей задачи */
.task-builder-container {
    background-color: #f0fdf4; /* Светло-зеленый фон */
    padding: 25px;
    border-radius: 15px;
    max-width: 800px;
    margin: 20px auto;
    font-family: Arial, sans-serif;
    text-align: center;
    box-shadow: 0 4px 10px rgba(0,0,0,0.05);
}

.task-title { color: #15803d; margin-bottom: 5px; }
.task-desc { color: #4b5563; font-size: 14px; margin-bottom: 20px; }

/* Кнопки-элементы */
.options-layout {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 20px;
    min-height: 50px;
}

.formula-element {
    background: #ffffff;
    border: none;
    border-radius: 10px;
    padding: 12px 20px;
    font-size: 18px;
    font-weight: bold;
    color: #9333ea; /* Фиолетовый текст */
    cursor: pointer;
    box-shadow: 0 3px 6px rgba(0,0,0,0.1);
    transition: transform 0.1s;
}

.formula-element:active { transform: translateY(2px); }

/* Черное поле */
.target-zone {
    background-color: #1a233e; /* Темно-синий/черный */
    min-height: 70px;
    border-radius: 12px;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
    padding: 10px;
    margin-bottom: 20px;
    border: 3px solid transparent;
}

/* Кнопки управления */
.button-group { display: flex; justify-content: center; gap: 10px; }

.check-btn { background-color: #22c55e; color: white; border: none; padding: 10px 20px; border-radius: 8px; cursor: pointer; font-weight: bold; }
.reset-btn { background-color: #94a3b8; color: white; border: none; padding: 10px 20px; border-radius: 8px; cursor: pointer; font-weight: bold; }

/* Обратная связь */
.target-zone.correct { border-color: #22c55e; }
.target-zone.wrong { border-color: #ef4444; }
.feedback-msg { margin-top: 15px; font-weight: bold; height: 20px; }


/* Стили для task_decision */
.task-decision-container {
    background-color: #fffaf0; /* Светло-оранжевый/бежевый фон */
    padding: 25px;
    border-radius: 15px;
    max-width: 800px;
    margin: 20px auto;
    font-family: Arial, sans-serif;
    box-shadow: 0 4px 10px rgba(0,0,0,0.05);
}

.task-title.orange { color: #c2410c; }

.problem-box {
    background: #ffffff;
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 20px;
    text-align: left;
    line-height: 1.6;
}

.formula-hint { color: #9333ea; font-weight: bold; margin-top: 10px; }

.input-zone {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 15px;
    margin-top: 20px;
}

.variable { font-size: 20px; font-weight: bold; }

.answer-input {
    width: 80px;
    height: 50px;
    border: 2px solid #ddd6fe;
    border-radius: 10px;
    text-align: center;
    font-size: 20px;
    font-weight: bold;
    outline: none;
    transition: border-color 0.3s;
}

.answer-input:focus { border-color: #9333ea; }

.unit { font-size: 18px; font-weight: bold; }

.check-btn.orange {
    background-color: #f97316;
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 10px;
    cursor: pointer;
    font-weight: bold;
    font-size: 16px;
    transition: background 0.3s;
}

.check-btn.orange:hover { background-color: #ea580c; }

/* Состояния валидации */
.answer-input.correct { border-color: #22c55e; background-color: #f0fdf4; }
.answer-input.wrong { border-color: #ef4444; background-color: #fef2f2; }

.feedback-msg {
    margin-top: 15px;
    font-weight: bold;
    text-align: center;
    height: 20px;
}