/* ========================================================================
   RegraDE3 — Calculator Variation Pages
   Shared styles for /simples/, /inversa/, /composta/, etc.
   ======================================================================== */

:root {
    --grad-start: #818cf8;
    --grad-mid: #c084fc;
    --grad-end: #f472b6;
    --accent-1: #818cf8;
    --accent-2: #c084fc;
    --accent-3: #f472b6;
    --bg-body: #06060e;
    --bg-surface: rgba(8, 8, 20, 0.65);
    --bg-card: rgba(10, 10, 28, 0.55);
    --bg-card-hover: rgba(16, 14, 40, 0.7);
    --bg-input: rgba(10, 8, 24, 0.8);
    --border-subtle: rgba(129, 140, 248, 0.08);
    --border-glow: rgba(192, 132, 252, 0.25);
    --text-primary: #e8eaf8;
    --text-secondary: #929ab8;
    --text-tertiary: #525870;
    --text-accent: #818cf8;
    --container-max: 1200px;
    --section-gap: 80px;
    --radius-sm: 10px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --radius-xl: 32px;
    --font-display: 'Space Grotesk', sans-serif;
    --font-body: 'Inter', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
    --transition-fast: 0.2s var(--ease-out-expo);
    --transition-med: 0.4s var(--ease-out-expo);
}

/* --- Breadcrumb --- */
.breadcrumb {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 100px 32px 0;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.82rem;
    color: var(--text-tertiary);
}
.breadcrumb a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color var(--transition-fast);
}
.breadcrumb a:hover { color: var(--accent-1); }
.breadcrumb svg { flex-shrink: 0; }

/* --- Variation Hero --- */
.var-hero {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 32px 32px 0;
    text-align: center;
}
.var-hero-icon {
    width: 72px; height: 72px;
    margin: 0 auto 20px;
    background: rgba(129, 140, 248, 0.06);
    border: 1px solid rgba(129, 140, 248, 0.15);
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-1);
}
.var-hero-icon svg { width: 36px; height: 36px; }
.var-hero h1 {
    font-family: var(--font-display);
    font-size: clamp(1.8rem, 4vw, 2.6rem);
    font-weight: 800;
    line-height: 1.15;
    letter-spacing: -0.02em;
    margin-bottom: 14px;
}
.var-hero p {
    color: var(--text-secondary);
    font-size: 1.05rem;
    max-width: 640px;
    margin: 0 auto;
    line-height: 1.7;
}

/* --- Calculator Card --- */
.var-calc-section {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 48px 32px 0;
}
.var-calc-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 28px;
}
.var-calc-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: 32px;
    backdrop-filter: blur(12px);
}
.var-calc-card-title {
    display: flex;
    align-items: center;
    gap: 10px;
    font-family: var(--font-display);
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 24px;
    color: var(--text-primary);
}
.var-calc-card-title svg { color: var(--accent-1); flex-shrink: 0; }

.var-form { display: flex; flex-direction: column; gap: 20px; }
.var-form-group { display: flex; flex-direction: column; gap: 6px; }
.var-form-label {
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.06em;
}
.var-form-row { display: flex; gap: 12px; }
.var-form-row .var-form-group { flex: 1; }
.var-input-wrap { position: relative; }
.var-input {
    width: 100%;
    padding: 13px 16px;
    background: var(--bg-input);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 1.05rem;
    font-family: var(--font-mono);
    font-weight: 500;
    outline: none;
    transition: all var(--transition-fast);
}
.var-input:focus {
    border-color: var(--accent-2);
    box-shadow: 0 0 0 3px rgba(192, 132, 252, 0.12);
}
.var-input::placeholder { color: var(--text-tertiary); font-family: var(--font-body); }
.var-input-unit {
    position: absolute;
    right: 12px; top: 50%;
    transform: translateY(-50%);
    color: var(--accent-1);
    font-family: var(--font-mono);
    font-weight: 600;
    font-size: 0.8rem;
    pointer-events: none;
}
.var-select {
    width: 100%;
    padding: 13px 16px;
    background: var(--bg-input);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 0.92rem;
    font-family: var(--font-body);
    cursor: pointer;
    outline: none;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg width='12' height='8' viewBox='0 0 12 8' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1.5L6 6.5L11 1.5' stroke='%23929ab8' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 14px center;
    padding-right: 38px;
    transition: all var(--transition-fast);
}
.var-select:focus {
    border-color: var(--accent-2);
    box-shadow: 0 0 0 3px rgba(192, 132, 252, 0.12);
}
.var-select option { background: #0a0a1c; }

.var-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 13px 24px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.92rem;
    font-family: var(--font-body);
    cursor: pointer;
    border: none;
    transition: all var(--transition-fast);
}
.var-btn-primary {
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2), var(--accent-3));
    color: #06060e;
}
.var-btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(192, 132, 252, 0.3);
}
.var-btn-outline {
    background: rgba(192, 132, 252, 0.06);
    color: var(--text-primary);
    border: 1px solid rgba(192, 132, 252, 0.18);
}
.var-btn-outline:hover {
    background: rgba(192, 132, 252, 0.12);
    border-color: rgba(192, 132, 252, 0.35);
}

/* Result card */
.var-result-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: 32px;
    backdrop-filter: blur(12px);
    display: flex;
    flex-direction: column;
    height: 100%;
}
.var-result-big {
    font-family: var(--font-display);
    font-size: clamp(2rem, 3.5vw, 2.8rem);
    font-weight: 800;
    background: linear-gradient(135deg, var(--accent-1), var(--accent-2), var(--accent-3));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-align: center;
    margin: 12px 0 8px;
    word-break: break-all;
}
.var-result-sub {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.88rem;
    margin-bottom: 16px;
}
.var-result-divider {
    height: 1px;
    background: linear-gradient(to right, transparent, var(--border-glow), transparent);
    margin: 12px 0;
}
.var-formula-card {
    background: rgba(192, 132, 252, 0.04);
    border: 1px solid rgba(192, 132, 252, 0.1);
    border-radius: var(--radius-md);
    padding: 18px;
    margin-bottom: 14px;
}
.var-formula-card h4 {
    font-family: var(--font-display);
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--accent-1);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin-bottom: 10px;
}
.var-formula-line {
    font-family: var(--font-mono);
    font-size: 0.88rem;
    color: var(--text-secondary);
    padding: 3px 0;
    line-height: 1.6;
}
.var-formula-line strong { color: var(--text-primary); }
.var-extras {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    margin-top: auto;
}
.var-extra-item {
    background: rgba(192, 132, 252, 0.04);
    border: 1px solid rgba(192, 132, 252, 0.08);
    border-radius: var(--radius-sm);
    padding: 12px;
}
.var-extra-label {
    font-size: 0.7rem;
    color: var(--text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    font-weight: 600;
    margin-bottom: 3px;
}
.var-extra-value {
    font-family: var(--font-mono);
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.92rem;
}

/* Live indicator */
.var-live {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--accent-1);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 8px;
}
.var-live-dot {
    width: 6px; height: 6px;
    background: var(--accent-1);
    border-radius: 50%;
    animation: varPulse 1.5s ease-in-out infinite;
}
@keyframes varPulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.5; transform: scale(0.8); }
}

/* --- Compound calculator extras --- */
.var-row-group {
    display: flex;
    flex-direction: column;
    gap: 12px;
}
.var-row-item {
    display: grid;
    grid-template-columns: auto 1fr 1fr auto;
    gap: 10px;
    align-items: end;
    background: rgba(192, 132, 252, 0.03);
    border: 1px solid rgba(192, 132, 252, 0.06);
    border-radius: var(--radius-sm);
    padding: 14px;
}
.var-row-num {
    font-family: var(--font-mono);
    font-weight: 700;
    font-size: 0.85rem;
    color: var(--accent-2);
    background: rgba(192, 132, 252, 0.08);
    width: 28px; height: 28px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    align-self: center;
}
.var-row-select {
    padding: 10px 12px;
    background: var(--bg-input);
    border: 1px solid var(--border-subtle);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 0.85rem;
    font-family: var(--font-body);
    outline: none;
    appearance: none;
    cursor: pointer;
    align-self: center;
}
.var-row-btn {
    background: none;
    border: none;
    color: var(--text-tertiary);
    cursor: pointer;
    padding: 6px;
    border-radius: 6px;
    transition: all var(--transition-fast);
    align-self: center;
}
.var-row-btn:hover { color: var(--accent-3); background: rgba(244, 114, 182, 0.08); }

/* --- Educational Content --- */
.var-content {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--section-gap) 32px 0;
}
.var-content-header {
    text-align: center;
    margin-bottom: 48px;
}
.var-content-tag {
    display: inline-block;
    background: rgba(129, 140, 248, 0.06);
    border: 1px solid rgba(129, 140, 248, 0.12);
    color: var(--accent-1);
    padding: 5px 16px;
    border-radius: 100px;
    font-size: 0.72rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    margin-bottom: 16px;
}
.var-content h2 {
    font-family: var(--font-display);
    font-size: clamp(1.6rem, 3vw, 2.2rem);
    font-weight: 800;
    line-height: 1.2;
    letter-spacing: -0.02em;
    margin-bottom: 12px;
}
.var-content-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
}
.var-content-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: 28px;
    transition: all var(--transition-med);
}
.var-content-card:hover {
    border-color: var(--border-glow);
    transform: translateY(-3px);
}
.var-content-card h3 {
    font-family: var(--font-display);
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 10px;
}
.var-content-card h3 span { color: var(--accent-1); }
.var-content-card p {
    color: var(--text-secondary);
    font-size: 0.92rem;
    line-height: 1.7;
}
.var-content-card ul {
    list-style: none;
    padding: 0;
    margin-top: 10px;
}
.var-content-card li {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.7;
    padding: 4px 0;
    padding-left: 20px;
    position: relative;
}
.var-content-card li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--accent-2);
}

/* --- FAQ --- */
.var-faq {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--section-gap) 32px 0;
}
.var-faq-header { text-align: center; margin-bottom: 40px; }
.var-faq-header h2 {
    font-family: var(--font-display);
    font-size: clamp(1.6rem, 3vw, 2.2rem);
    font-weight: 800;
    letter-spacing: -0.02em;
}
.var-faq-list {
    max-width: 780px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.var-faq-item {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: all var(--transition-fast);
}
.var-faq-item:hover { border-color: var(--border-glow); }
.var-faq-q {
    width: 100%;
    text-align: left;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 18px 22px;
    background: none;
    border: none;
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
}
.var-faq-chevron {
    flex-shrink: 0;
    color: var(--text-tertiary);
    transition: transform var(--transition-fast);
}
.var-faq-item.open .var-faq-chevron {
    transform: rotate(180deg);
    color: var(--accent-1);
}
.var-faq-a {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-med);
}
.var-faq-item.open .var-faq-a { max-height: 400px; }
.var-faq-a p {
    padding: 0 22px 18px;
    color: var(--text-secondary);
    font-size: 0.92rem;
    line-height: 1.7;
}

/* --- Cross-links grid --- */
.var-crosslinks {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--section-gap) 32px 60px;
}
.var-crosslinks-header { text-align: center; margin-bottom: 40px; }
.var-crosslinks-header h2 {
    font-family: var(--font-display);
    font-size: clamp(1.4rem, 2.5vw, 1.8rem);
    font-weight: 800;
    letter-spacing: -0.02em;
}
.var-crosslinks-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}
.var-crosslink-card {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 18px 20px;
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    text-decoration: none;
    color: var(--text-primary);
    transition: all var(--transition-med);
}
.var-crosslink-card:hover {
    border-color: var(--border-glow);
    background: var(--bg-card-hover);
    transform: translateY(-3px);
    box-shadow: 0 12px 36px rgba(192, 132, 252, 0.06);
    color: var(--text-primary);
}
.var-crosslink-icon {
    width: 40px; height: 40px;
    flex-shrink: 0;
    background: rgba(129, 140, 248, 0.06);
    border: 1px solid rgba(129, 140, 248, 0.12);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-1);
}
.var-crosslink-icon svg { width: 20px; height: 20px; }
.var-crosslink-name {
    font-weight: 600;
    font-size: 0.88rem;
}
.var-crosslink-card.active {
    border-color: var(--accent-2);
    background: rgba(192, 132, 252, 0.06);
}

/* --- Responsive --- */
@media (max-width: 1024px) {
    .var-calc-grid { grid-template-columns: 1fr; }
    .var-content-grid { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
    .var-crosslinks-grid { grid-template-columns: 1fr 1fr; }
    .breadcrumb { padding-top: 80px; }
    .var-form-row { flex-direction: column; }
    .var-row-item { grid-template-columns: auto 1fr auto; }
    .var-row-item .var-form-group:nth-child(3) { grid-column: 2; }
}
@media (max-width: 480px) {
    .var-crosslinks-grid { grid-template-columns: 1fr; }
    .var-extras { grid-template-columns: 1fr; }
}