/* --- Стили для Прогрессий (Purple Theme) --- */
:root {
    --accent-purple: #9333EA; /* Purple 600 */
    --accent-purple-light: #F3E8FF;
    --gradient-purple-card: linear-gradient(135deg, #A855F7 0%, #7E22CE 100%);
}

.calc-header { margin-bottom: 32px; }
.subtitle { color: var(--text-secondary); margin-top: 8px; }

.calc-grid { display: grid; grid-template-columns: 1fr; gap: 24px; align-items: start; }
@media (min-width: 900px) { .calc-grid { grid-template-columns: 1fr 1fr; } }

/* Inputs */
.calc-inputs { gap: 16px; }
.input-group { margin-bottom: 16px; }
.input-group label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 8px; color: var(--text-primary); }

.input-wrapper { position: relative; display: flex; align-items: center; }

.input-wrapper input {
    width: 100%; padding: 14px 16px; 
    font-size: 18px; font-weight: 500;
    border: 1px solid #E5E7EB; border-radius: 12px;
    outline: none; transition: border 0.2s;
    font-family: var(--font-main);
}
.input-wrapper input:focus { border-color: var(--accent-purple); box-shadow: 0 0 0 3px rgba(147, 51, 234, 0.15); }

/* Mode Switcher */
.mode-switcher {
    display: flex; background: #F3F4F6; padding: 4px;
    border-radius: 12px; margin-bottom: 24px; gap: 4px;
}
.mode-btn {
    flex: 1; padding: 10px 4px; border: none; background: transparent;
    color: var(--text-secondary); font-size: 13px; font-weight: 600;
    border-radius: 8px; cursor: pointer; transition: all 0.2s; text-align: center;
}
.mode-btn.active { background: #fff; color: var(--text-primary); box-shadow: 0 2px 8px rgba(0,0,0,0.05); }

/* Range Slider */
.range-wrapper { margin-top: 8px; display: flex; align-items: center; gap: 12px; }
.range-slider { flex-grow: 1; -webkit-appearance: none; height: 6px; background: #E5E7EB; border-radius: 5px; outline: none; cursor: pointer; }
.range-slider::-webkit-slider-thumb {
    -webkit-appearance: none; width: 20px; height: 20px; border-radius: 50%;
    background: var(--accent-purple); cursor: pointer; border: 2px solid #fff;
    box-shadow: 0 2px 6px rgba(0,0,0,0.2); transition: transform 0.1s;
}
.range-val { font-weight: 700; color: var(--accent-purple); font-size: 14px; width: 30px; text-align: right; }
.label-row { display: flex; justify-content: space-between; align-items: center; margin-bottom: 8px; }
.helper-text { font-size: 11px; color: var(--text-secondary); margin-top: 6px; }

/* --- Результаты (Purple Card) --- */
.card--purple { background: var(--gradient-purple-card); color: #fff; border: none; }
.card--purple h2 { color: rgba(255,255,255,0.95); margin-bottom: 24px; }
@media (min-width: 900px) { .sticky-card { position: sticky; top: 24px; } }

.progression-stats {
    display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-bottom: 24px;
}
.stat-box {
    background: rgba(255,255,255,0.15); padding: 12px; border-radius: 12px;
    display: flex; flex-direction: column; text-align: center;
    backdrop-filter: blur(4px);
}
.stat-label { font-size: 11px; text-transform: uppercase; opacity: 0.8; margin-bottom: 4px; }
.stat-val { font-size: 20px; font-weight: 700; word-break: break-all; }

/* График (Столбики) */
.chart-box {
    height: 180px; background: rgba(0,0,0,0.2); border-radius: 12px;
    padding: 16px 12px 24px 12px; 
    position: relative; display: flex; align-items: flex-end; justify-content: space-between;
    gap: 4px;
}
.chart-bars {
    display: flex; align-items: flex-end; justify-content: space-between;
    width: 100%; height: 100%; gap: 2px;
}
.bar {
    background: #fff; border-radius: 4px 4px 0 0;
    transition: height 0.3s ease; min-height: 2px;
    opacity: 0.8; flex: 1;
}
.bar:hover { opacity: 1; }

.chart-axis {
    position: absolute; bottom: 6px; left: 12px; right: 12px;
    display: flex; justify-content: space-between;
    font-size: 10px; opacity: 0.6; font-family: monospace;
}

.summary-divider { height: 1px; background: rgba(255,255,255,0.2); margin: 20px 0; }

.formulas-display { font-family: 'Courier New', monospace; font-size: 13px; opacity: 0.9; }
.math-row { margin-bottom: 8px; word-break: break-all; }


/* --- НОВЫЕ ИНФОРМАЦИОННЫЕ БЛОКИ (Purple Theme) --- */

.info-wrapper {
    padding: 60px 0 60px 0;
    margin-top: 60px;
    border-top: 1px solid rgba(0,0,0,0.06);
    margin-bottom: 20px;
}

/* Центрирование контента */
.formulas-section,
.calc-description,
.faq-section {
    max-width: 800px;
    width: 100%;
    margin-left: auto;
    margin-right: auto;
}

/* Заголовки с иконками */
.icon-heading {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    margin-bottom: 24px;
    font-size: 24px;
    font-weight: 800;
    color: var(--text-primary);
    line-height: 1.3;
}

.header-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 14px;
    background: #fff;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    flex-shrink: 0;
    margin-top: -4px;
}

.header-icon svg { width: 24px; height: 24px; stroke-width: 2px; }

/* Цвета иконок */
.blue-icon svg { color: #2563EB; }
.orange-icon svg { color: #F59E0B; }
.green-icon svg { color: #10B981; }
.red-icon svg { color: #E11D48; }
.purple-icon svg { color: #9333EA; }

/* Маленькие подзаголовки */
.small-heading {
    margin-top: 40px;
    margin-bottom: 16px;
    font-size: 20px;
}
.small-heading .header-icon { width: 40px; height: 40px; }
.small-heading .header-icon svg { width: 20px; height: 20px; }

.intro-text {
    font-size: 16px;
    color: var(--text-secondary);
    margin-bottom: 32px;
    line-height: 1.6;
}

/* --- Секция Формул --- */
.formulas-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
    margin-bottom: 48px;
}

.formula-card {
    background: #fff;
    border: 1px solid rgba(0,0,0,0.04);
    box-shadow: var(--shadow-soft);
    border-radius: var(--radius-lg); 
    padding: 24px;
    transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
    display: flex;
    flex-direction: column;
}
.formula-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }

/* Вертикальный хедер (бейдж сверху) */
.formula-header {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
    margin-bottom: 16px;
}

.formula-card h3 {
    margin: 0;
    font-size: 18px;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.3;
}

/* Бейджи */
.badge-blue {
    background: #2563EB; color: #fff;
    padding: 6px 12px; border-radius: 99px;
    font-size: 11px; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.05em;
    display: inline-block;
}
.badge-green {
    background: #10B981; color: #fff;
    padding: 6px 12px; border-radius: 99px;
    font-size: 11px; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.05em;
    display: inline-block;
}

.formula-card p {
    font-size: 14px; color: var(--text-secondary);
    margin: 0; line-height: 1.5; font-weight: 500;
}

.math-expression {
    background: #F9FAFB;
    border: 1px solid #E5E7EB;
    padding: 12px 16px;
    border-radius: 12px;
    font-weight: 700;
    color: var(--accent-purple); /* Фиолетовый акцент для формул */
    text-align: center;
    margin-bottom: 16px;
    font-size: 15px;
}

/* Разделитель */
.soft-divider {
    border: none; height: 1px;
    background: linear-gradient(90deg, transparent, #E5E7EB, transparent);
    margin: 48px auto;
    max-width: 800px;
    width: 100%;
}

/* Описание */
.calc-description p {
    font-size: 16px; line-height: 1.7;
    color: var(--text-secondary); margin-bottom: 24px;
}
.calc-description strong { color: var(--text-primary); }

/* FAQ */
.faq-section .faq-item {
    background: #fff; border: 1px solid #E5E7EB;
    border-radius: 12px; margin-bottom: 12px;
    overflow: hidden; transition: all 0.2s ease;
}

.faq-section .faq-item[open] {
    border-color: var(--accent-purple); 
    box-shadow: 0 4px 20px rgba(147, 51, 234, 0.15); /* Purple shadow */
}

.faq-section summary.faq-question {
    padding: 16px 20px; cursor: pointer;
    font-weight: 600; color: var(--text-primary);
    list-style: none; position: relative;
    display: flex; justify-content: space-between;
    align-items: center; transition: background 0.2s;
}

.faq-section summary.faq-question:hover { background-color: #F9FAFB; }

.faq-section .faq-item[open] summary.faq-question {
    color: var(--accent-purple);
    background: var(--accent-purple-light);
}

.faq-question::after {
    content: '+'; font-size: 20px;
    color: var(--text-secondary); font-weight: 400; line-height: 1;
}
.faq-question .icon-plus { display: none; }

.faq-section .faq-item[open] summary.faq-question::after {
    content: '−'; color: var(--accent-purple);
}

.faq-answer {
    padding: 20px; color: var(--text-secondary);
    line-height: 1.6; font-size: 15px;
}

/* --- МОБИЛЬНАЯ АДАПТАЦИЯ --- */
@media (max-width: 900px) {
    .formulas-grid { grid-template-columns: 1fr; gap: 16px; margin-bottom: 32px; }
    
    .icon-heading { font-size: 20px; gap: 12px; margin-bottom: 20px; }
    .header-icon { width: 40px; height: 40px; border-radius: 12px; }
    .header-icon svg { width: 20px; height: 20px; }
    
    .formula-card { 
        padding: 24px; 
        text-align: center; 
        align-items: center; 
    }

    .formula-header {
        align-items: center;
        width: 100%;
    }

    .math-expression {
        width: 100%;
        max-width: 300px;
        margin-left: auto;
        margin-right: auto;
    }

    .info-wrapper { margin-top: 40px; padding-top: 40px; }
}