/* ============================================
   Saldatura Testa a Testa PP - DVS 2207-11
   Tema teal/cyan (industriale)
   ============================================ */

:root {
    --color-bg: #0f1419;
    --color-bg-card: #1a2530;
    --color-surface: #243447;
    
    --color-primary: #14b8a6;
    --color-primary-dim: #0d9488;
    --color-accent: #2dd4bf;
    
    --color-text: #e8edf4;
    --color-text-muted: #94a3b8;
    --color-text-dim: #64748b;
    
    --color-border: #334155;
    --color-border-focus: #14b8a6;
    
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.3);
    
    --font-sans: 'Outfit', -apple-system, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    
    --transition: 0.2s ease;
}

*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

body::before {
    content: '';
    position: fixed;
    inset: 0;
    background: 
        radial-gradient(ellipse 80% 50% at 50% -20%, rgba(20, 184, 166, 0.08), transparent),
        radial-gradient(ellipse 60% 40% at 100% 100%, rgba(45, 212, 191, 0.05), transparent);
    pointer-events: none;
    z-index: 0;
}

.app-container {
    position: relative;
    z-index: 1;
    max-width: 560px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.header {
    margin-bottom: 2.5rem;
    text-align: center;
}

.back-link {
    display: inline-block;
    font-size: 0.9rem;
    color: var(--color-primary);
    text-decoration: none;
    margin-bottom: 1rem;
    transition: opacity 0.2s;
}

.back-link:hover {
    opacity: 0.8;
}

.header-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-icon {
    width: 36px;
    height: 36px;
    color: var(--color-primary);
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 600;
    letter-spacing: -0.02em;
}

.subtitle {
    font-size: 0.9rem;
    color: var(--color-text-muted);
}

.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.calculator-card,
.result-card,
.info-card {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 1.75rem;
    box-shadow: var(--shadow-md);
}

.calculator-card .card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1.5rem;
}

.result-card .result-header {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.result-header-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.card-header h2,
.result-header h2 {
    font-size: 1.1rem;
    font-weight: 600;
}

.result-buttons {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex-shrink: 0;
}

.result-value {
    margin-top: 0.25rem;
}

.norm-badge {
    font-size: 0.7rem;
    padding: 0.25rem 0.6rem;
    background: rgba(20, 184, 166, 0.2);
    color: var(--color-primary);
    border-radius: 999px;
    font-weight: 500;
}

.btn-print {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.5rem 0.9rem;
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-primary);
    background: rgba(20, 184, 166, 0.15);
    border: 1px solid rgba(20, 184, 166, 0.35);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: background var(--transition), border-color var(--transition);
}

.btn-print:hover {
    background: rgba(20, 184, 166, 0.25);
    border-color: var(--color-primary);
}

.btn-print svg {
    width: 18px;
    height: 18px;
}

.calc-form {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.form-group.hidden {
    display: none;
}

.form-group label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text-muted);
}

.form-group select,
.form-group input[type="number"] {
    font-family: var(--font-sans);
    font-size: 0.95rem;
    padding: 0.75rem 1rem;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text);
    transition: border-color var(--transition);
}

.form-group select {
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2394a3b8' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 1rem center;
    padding-right: 2.5rem;
}

.form-group input:hover,
.form-group select:hover {
    border-color: var(--color-text-dim);
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--color-border-focus);
    box-shadow: 0 0 0 3px rgba(20, 184, 166, 0.2);
}

.input-hint {
    font-size: 0.75rem;
    color: var(--color-text-dim);
}

.checkbox-group {
    flex-direction: column;
}

.checkbox-group .checkbox-label {
    flex-direction: row;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    font-weight: 500;
}

.checkbox-label input[type="checkbox"] {
    width: 1.1rem;
    height: 1.1rem;
    accent-color: var(--color-primary);
}

.btn-calculate {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 1rem 1.5rem;
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 600;
    color: #0f1419;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dim) 100%);
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: transform var(--transition), box-shadow var(--transition);
    margin-top: 0.5rem;
}

.btn-calculate:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 20px rgba(20, 184, 166, 0.4);
}

.btn-calculate:active {
    transform: translateY(0);
}

.btn-icon {
    width: 20px;
    height: 20px;
}

.result-card {
    border-color: rgba(20, 184, 166, 0.25);
}

.result-value {
    font-family: var(--font-mono);
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--color-primary);
    line-height: 1.8;
}

.result-value.has-value {
    animation: pulse 0.5s ease;
}

.result-heat {
    color: var(--color-accent);
}

.result-cool {
    color: var(--color-primary);
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

.result-details {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--color-border);
    font-size: 0.9rem;
    color: var(--color-text-muted);
    line-height: 1.8;
    white-space: pre-line;
}

.result-note {
    margin-top: 1rem;
    padding: 0.75rem;
    background: rgba(0, 0, 0, 0.25);
    border-radius: var(--radius-sm);
    font-size: 0.8rem;
    color: var(--color-text-dim);
}

.result-note p {
    margin: 0;
}

.result-note a {
    color: var(--color-primary);
    text-decoration: none;
}

.result-note a:hover {
    text-decoration: underline;
}

.info-card h3 {
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.info-card ul {
    list-style: none;
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

.info-card li {
    padding: 0.35rem 0;
    padding-left: 1.25rem;
    position: relative;
}

.info-card li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--color-primary);
}

.footer {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--color-border);
    text-align: center;
    font-size: 0.8rem;
    color: var(--color-text-dim);
}

.footer a {
    color: var(--color-primary);
    text-decoration: none;
}

.footer a:hover {
    text-decoration: underline;
}

@media (max-width: 480px) {
    .app-container { padding: 1.5rem 1rem; }
    .logo h1 { font-size: 1.25rem; }
    .calculator-card, .result-card, .info-card { padding: 1.25rem; }
    .result-value { font-size: 0.9rem; }
}

:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

@media print {
    body::before { display: none; }
    .calculator-card, .btn-print, .btn-calculate { display: none !important; }
    .result-card, .info-card { box-shadow: none; border-color: #ccc; }
    body { background: #fff; color: #000; }
    .result-value { color: #0d9488; }
}