/* --- Стили для Лестницы (Wood Theme) --- */
:root {
    --accent-wood: #A16207; /* Yellow/Brown 700 */
    --accent-wood-light: #FEFCE8;
    --gradient-wood-card: linear-gradient(135deg, #B45309 0%, #78350F 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: 8px; color: var(--text-primary); }

/* FIX стрелок */
input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
input[type="number"] { -moz-appearance: textfield; }

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

.input-wrapper input {
    width: 100%; padding: 14px 16px; padding-right: 50px;
    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-wood); box-shadow: 0 0 0 3px rgba(161, 98, 7, 0.15); }

.suffix { 
    position: absolute; right: 16px; top: 50%; transform: translateY(-50%);
    color: var(--text-secondary); pointer-events: none; font-size: 14px; 
}
.helper-text { font-size: 12px; color: var(--text-secondary); margin-top: 6px; }

.divider { border-top: 1px solid #E5E7EB; margin: 24px 0; }

/* Counter Mini */
.counter-mini {
    display: flex; align-items: center; background: #fff;
    border: 1px solid #E5E7EB; border-radius: 10px; overflow: hidden; height: 48px;
}
.cnt-btn {
    width: 40px; height: 100%; border: none; background: #F9FAFB;
    cursor: pointer; font-weight: bold; color: var(--text-secondary); font-size: 18px;
}
.cnt-btn:hover { background: #E5E7EB; color: var(--text-primary); }
.counter-mini input {
    width: 100%; height: 100%; text-align: center; border: none; 
    font-weight: 600; font-size: 16px; outline: none; padding: 0;
}

/* Результаты (Wood Card) */
.card--wood { background: var(--gradient-wood-card); color: #fff; border: none; }
.card--wood h2 { color: rgba(255,255,255,0.95); margin-bottom: 20px; font-size: 18px; }
@media (min-width: 900px) { .sticky-card { position: sticky; top: 24px; } }

/* Визуализация Лестницы */
.stairs-visual-box {
    height: 250px; 
    background: rgba(255,255,255,0.1); 
    border-radius: 16px;
    margin-bottom: 24px; 
    position: relative;
    padding: 30px 60px 30px 30px; 
    box-sizing: border-box;
}

/* Контейнер ступеней */
.stairs-draw {
    width: 100%; height: 100%;
    position: relative; 
    border-bottom: 2px solid rgba(255,255,255,0.3); /* Пол 1-го этажа */
    border-right: 2px solid rgba(255,255,255,0.3);  /* Стена 2-го этажа */
}

/* Сама ступенька (уголок) */
.step-visual {
    position: absolute;
    background: transparent;
    border-top: 3px solid rgba(255,255,255,0.9); /* Проступь (жирнее) */
    border-right: 3px solid rgba(255,255,255,0.5); /* Подступенок */
    box-sizing: border-box;
}

/* Размеры на чертеже */
.dimension {
    position: absolute; font-size: 11px; color: rgba(255,255,255,0.8);
    font-family: monospace; font-weight: 700;
}

/* Высота (H) */
.dim-h { 
    top: 30px; 
    right: 15px; 
    height: calc(100% - 30px); 
    border-left: 1px dashed rgba(255,255,255,0.4); 
    padding-left: 6px; 
    display: flex; align-items: center; justify-content: flex-start;
}

/* Длина (L) */
.dim-l { 
    bottom: 5px; 
    left: 30px; 
    width: calc(100% - 60px);
    border-bottom: 1px dashed rgba(255,255,255,0.4); 
    text-align: center; padding-bottom: 4px;
}

/* Метрики */
.metrics-grid { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 8px; margin-bottom: 24px; }
.metric-item {
    background: rgba(0,0,0,0.2); padding: 10px 4px; border-radius: 10px;
    display: flex; flex-direction: column; align-items: center; text-align: center;
}
.metric-label { font-size: 10px; opacity: 0.7; text-transform: uppercase; margin-bottom: 4px; }
.metric-item strong { font-size: 16px; font-weight: 700; }

.summary-divider { height: 1px; background: rgba(255,255,255,0.2); margin: 24px 0; }

.tip-box {
    font-size: 13px; line-height: 1.5; color: #ffffff !important;
    background: rgba(0, 0, 0, 0.3) !important; padding: 16px; border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.15);
}
.tip-box p { margin: 0; color: #ffffff !important; }

/* --- НОВЫЕ ИНФОРМАЦИОННЫЕ БЛОКИ (Адаптация под Wood/Stairs) --- */

.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: #EA580C; }
.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;
}

.formula-card small {
    display: block; margin-top: 12px; font-size: 12px; color: var(--text-secondary); opacity: 0.7;
}

.math-expression {
    background: #F9FAFB;
    border: 1px solid #E5E7EB;
    padding: 12px 16px;
    border-radius: 12px;
    font-weight: 700;
    color: var(--accent-wood); /* Wood Accent */
    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 (Новый стиль под Wood) */
.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-wood); 
    box-shadow: 0 4px 20px rgba(161, 98, 7, 0.1); /* Wood Shadow */
}

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;
}

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

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

.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; }
}