/* --- Стили для Затирки (Stone Theme) --- */
:root {
    --accent-stone: #78716C; /* Stone 500 */
    --accent-stone-light: #F5F5F4;
    --gradient-stone-card: linear-gradient(135deg, #52525B 0%, #27272A 100%);
}

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

/* Сетка */
.calc-grid { display: grid; grid-template-columns: 1fr; gap: 24px; align-items: start; }
@media (min-width: 900px) { .calc-grid { grid-template-columns: 1.2fr 0.8fr; } }

/* Inputs */
.calc-inputs { gap: 16px; }
.input-group { margin-bottom: 16px; }
.input-group label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 6px; color: var(--text-primary); }
.input-wrapper { position: relative; display: flex; align-items: center; }

.input-wrapper input {
    width: 100%; padding: 14px 16px; padding-right: 40px;
    font-size: 18px; font-weight: 500;
    border: 1px solid #E5E7EB; border-radius: 12px;
    outline: none; transition: border 0.2s, box-shadow 0.2s;
    font-family: var(--font-main);
}
.input-wrapper input:focus { border-color: var(--accent-stone); box-shadow: 0 0 0 3px rgba(120, 113, 108, 0.15); }
.suffix { position: absolute; right: 16px; color: var(--text-secondary); pointer-events: none; }

/* Сетки полей */
.row-3-col { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 12px; }
.row-2-col { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }

/* Выбор плотности */
.density-selector { display: flex; gap: 8px; }
.density-option { flex: 1; cursor: pointer; }
.density-option input { display: none; }
.density-card {
    border: 1px solid #E5E7EB; border-radius: 12px; padding: 10px;
    display: flex; flex-direction: column; align-items: center; text-align: center;
    transition: all 0.2s; background: #fff; height: 100%;
}
.density-card span { font-weight: 600; font-size: 13px; color: var(--text-primary); margin-bottom: 2px; }
.density-card small { font-size: 11px; color: var(--text-secondary); }

.density-option input:checked + .density-card {
    border-color: var(--accent-stone); background: var(--accent-stone-light);
    color: var(--accent-stone); box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}

/* Результаты (Stone Card) */
.card--stone { 
    background: var(--gradient-stone-card); 
    color: #fff; 
    border: none; 
}
.card--stone h2 { color: rgba(255,255,255,0.9); margin-bottom: 20px; font-size: 16px; }
@media (min-width: 900px) { .sticky-card { position: sticky; top: 24px; } }

.big-result {
    font-size: 56px; font-weight: 800; line-height: 1; margin-bottom: 24px;
    display: flex; align-items: baseline; gap: 12px; white-space: nowrap;
}
.big-result small { font-size: 24px; font-weight: 600; opacity: 0.8; }

/* Визуализация ведер */
.buckets-visual { 
    display: flex; align-items: center; justify-content: space-between; 
    background: rgba(255,255,255,0.15); 
    padding: 16px; 
    border-radius: 12px;
    margin-bottom: 20px;
    backdrop-filter: blur(4px);
}
.bucket-item { display: flex; align-items: center; gap: 12px; }

.bucket-icon { 
    display: flex; align-items: center; justify-content: center;
    width: 40px; height: 40px;
    color: #fff; opacity: 0.9; flex-shrink: 0;
}
.bucket-icon svg { width: 100%; height: 100%; display: block; }

.bucket-info { display: flex; flex-direction: column; line-height: 1.2; }
.bucket-info strong { font-size: 20px; font-weight: 700; color: #fff; }
.bucket-info span { font-size: 11px; opacity: 0.8; white-space: nowrap; }
.bucket-or { font-size: 10px; opacity: 0.5; font-weight: 700; text-transform: uppercase; margin: 0 4px; }

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

.details-list { display: flex; flex-direction: column; gap: 10px; margin-bottom: 20px; }
.detail-row {
    display: flex; justify-content: space-between; align-items: center;
    border-bottom: 1px solid rgba(255,255,255,0.2); padding-bottom: 10px; font-size: 14px;
}
.detail-row:last-child { border-bottom: none; }
.detail-row strong { font-size: 16px; font-weight: 700; }

.tip-box {
    font-size: 13px; line-height: 1.4; 
    color: #ffffff; 
    background: rgba(255, 255, 255, 0.15); 
    padding: 14px; 
    border-radius: 12px;
    backdrop-filter: blur(4px); 
    margin-top: 16px;
}
.tip-box p { margin: 0; color: rgba(255, 255, 255, 0.95); }
.tip-box strong {
    font-weight: 700; color: #fff;
    background: rgba(255, 255, 255, 0.1); padding: 0 4px; border-radius: 4px;
}


/* --- НОВЫЕ ИНФОРМАЦИОННЫЕ БЛОКИ --- */

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

.info-wrapper .container {
    max-width: 800px;
    margin: 0 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: #EF4444; }

/* 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: #F5F5F4; /* Светло-серый фон */
    border: 1px solid #E7E5E4;
    padding: 12px 16px;
    border-radius: 12px;
    font-weight: 700;
    color: var(--accent-stone); /* Каменный цвет */
    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 0;
}

/* 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 (Стиль Grout) */
.faq-grout-style .faq-item {
    background: #fff; border: 1px solid #E5E7EB;
    border-radius: 12px; margin-bottom: 12px;
    overflow: hidden; transition: all 0.2s ease;
}

.faq-grout-style .faq-item[open] {
    border-color: var(--accent-stone); 
    box-shadow: 0 4px 20px rgba(120, 113, 108, 0.1);
}

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

.faq-grout-style .faq-item[open] summary.faq-question {
    color: #57534E;
    background: #F5F5F4; /* Светло-каменный */
}

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

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

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

/* --- МОБИЛЬНАЯ АДАПТАЦИЯ --- */
@media (max-width: 900px) {
    /* Сетка в 1 колонку */
    .formulas-grid { grid-template-columns: 1fr; gap: 16px; margin-bottom: 32px; }
    
    /* Уменьшаем шрифты */
    .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; }
    
    /* Центрирование контента карточки */
    .formula-card { 
        padding: 24px; 
        text-align: center; 
        align-items: center; 
    }

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

    /* Блок с формулой по центру */
    .math-expression {
        width: 100%;
        max-width: 300px;
        margin-left: auto;
        margin-right: auto;
    }

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