/*
 * Friction Loss Calculator Pro - Styles
 * Prefixed selectors, scoped under .flc-tool
 */

.flc-tool {
    --flc-bg: #1a1c23;
    --flc-surface: #22252f;
    --flc-surface-hover: #2a2e3a;
    --flc-border: #2c2f38;
    --flc-text: #e1e4ed;
    --flc-text-secondary: #9aa0b4;
    --flc-accent: #3b82f6;
    --flc-accent-hover: #5a9cff;
    --flc-accent-muted: rgba(59, 130, 246, 0.12);
    --flc-accent-muted-hover: rgba(59, 130, 246, 0.22);
    --flc-success: #10b981;
    --flc-warning: #f59e0b;
    --flc-danger: #ef4444;
    --flc-radius: 8px;
    --flc-transition: 0.2s ease;

    background: var(--flc-bg);
    color: var(--flc-text);
    font-family: system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.5;
    max-width: 960px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
    box-sizing: border-box;
}

.flc-tool *,
.flc-tool *::before,
.flc-tool *::after {
    box-sizing: border-box;
}

/* ---------- Typography ---------- */
.flc-tool h1, .flc-tool h2, .flc-tool h3 {
    margin: 0 0 0.75rem;
    font-weight: 600;
    line-height: 1.3;
}

.flc-tool h1 { font-size: 2rem; }
.flc-tool h2 { font-size: 1.4rem; color: var(--flc-accent-hover); }
.flc-tool h3 { font-size: 1.1rem; color: var(--flc-text); }

.flc-tool p, .flc-tool li {
    color: var(--flc-text-secondary);
}

.flc-tool a {
    color: var(--flc-accent);
    text-decoration: none;
}
.flc-tool a:hover { text-decoration: underline; }

/* ---------- Hero ---------- */
.flc-hero {
    text-align: center;
    margin-bottom: 2rem;
}
.flc-hero-description {
    font-size: 1.1rem;
    max-width: 700px;
    margin: 0 auto 1rem;
}

/* ---------- Notes & Disclaimers ---------- */
.flc-note {
    font-size: 0.85rem;
    background: var(--flc-surface);
    border-left: 3px solid var(--flc-accent);
    padding: 0.8rem 1rem;
    border-radius: var(--flc-radius);
    color: var(--flc-text-secondary);
}
.flc-note-disclaimer {
    border-color: var(--flc-warning);
}

/* ---------- Mode Tabs ---------- */
.flc-mode-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}
.flc-mode-tab {
    background: var(--flc-surface);
    border: 1px solid var(--flc-border);
    color: var(--flc-text-secondary);
    padding: 0.65rem 1.2rem;
    border-radius: var(--flc-radius);
    cursor: pointer;
    font-size: 0.9rem;
    transition: background var(--flc-transition), color var(--flc-transition), border-color var(--flc-transition);
}
.flc-mode-tab:hover {
    background: var(--flc-accent-muted-hover);
    border-color: var(--flc-accent);
    color: var(--flc-text);
}
.flc-mode-tab.active {
    background: var(--flc-accent-muted);
    border-color: var(--flc-accent);
    color: var(--flc-accent-hover);
    font-weight: 600;
}
.flc-mode-tab:focus-visible {
    outline: 2px solid var(--flc-accent);
    outline-offset: 2px;
}

/* ---------- Unit System Toggle ---------- */
.flc-unit-system {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}
.flc-toggle-group {
    display: inline-flex;
    border: 1px solid var(--flc-border);
    border-radius: var(--flc-radius);
    overflow: hidden;
}
.flc-toggle-btn {
    background: transparent;
    border: none;
    padding: 0.5rem 1.2rem;
    color: var(--flc-text-secondary);
    cursor: pointer;
    transition: background var(--flc-transition), color var(--flc-transition);
}
.flc-toggle-btn:hover {
    background: var(--flc-accent-muted-hover);
    color: var(--flc-text);
}
.flc-toggle-btn.active {
    background: var(--flc-accent);
    color: #fff;
    font-weight: 600;
}
.flc-toggle-btn:focus-visible {
    outline: 2px solid var(--flc-accent);
    outline-offset: -2px;
}

/* ---------- Form ---------- */
.flc-inputs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}
.flc-field {
    display: flex;
    flex-direction: column;
    position: relative;
}
.flc-label {
    font-size: 0.85rem;
    margin-bottom: 0.25rem;
    color: var(--flc-text);
    font-weight: 500;
}
.flc-input, .flc-select {
    background: var(--flc-surface);
    border: 1px solid var(--flc-border);
    border-radius: var(--flc-radius);
    padding: 0.65rem 0.8rem;
    color: var(--flc-text);
    font-size: 0.95rem;
    transition: border-color var(--flc-transition), background var(--flc-transition);
    width: 100%;
}
.flc-input:hover, .flc-select:hover {
    border-color: var(--flc-accent);
}
.flc-input:focus, .flc-select:focus {
    outline: 2px solid var(--flc-accent);
    outline-offset: 2px;
    border-color: var(--flc-accent);
}
.flc-unit-hint {
    position: absolute;
    right: 0.8rem;
    top: 2.15rem;
    color: var(--flc-text-secondary);
    font-size: 0.8rem;
}

/* ---------- Buttons ---------- */
.flc-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-bottom: 2rem;
}
.flc-button {
    border: 1px solid transparent;
    padding: 0.65rem 1.4rem;
    border-radius: var(--flc-radius);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: background var(--flc-transition), color var(--flc-transition), border-color var(--flc-transition), transform var(--flc-transition), box-shadow var(--flc-transition);
    display: inline-flex;
    align-items: center;
    justify-content: center;
}
.flc-button:focus-visible {
    outline: 2px solid var(--flc-accent);
    outline-offset: 2px;
}
.flc-button-primary {
    background: var(--flc-accent);
    color: #fff;
    border-color: var(--flc-accent);
}
.flc-button-primary:hover {
    background: var(--flc-accent-hover);
    border-color: var(--flc-accent-hover);
}
.flc-button-secondary {
    background: var(--flc-accent-muted);
    color: var(--flc-text);
    border-color: var(--flc-border);
}
.flc-button-secondary:hover {
    background: var(--flc-accent-muted-hover);
    border-color: var(--flc-accent);
}
.flc-button-ghost {
    background: transparent;
    color: var(--flc-accent);
    border-color: var(--flc-border);
}
.flc-button-ghost:hover {
    background: var(--flc-accent-muted-hover);
    border-color: var(--flc-accent);
}
.flc-button:disabled {
    opacity: 0.55;
    pointer-events: none;
}

/* ---------- Results ---------- */
.flc-results {
    margin-top: 2rem;
}
.flc-results-title {
    margin-bottom: 1rem;
}
.flc-cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}
.flc-card {
    background: var(--flc-surface);
    border: 1px solid var(--flc-border);
    border-radius: var(--flc-radius);
    padding: 1.2rem;
}
.flc-card-title {
    font-size: 0.85rem;
    color: var(--flc-text-secondary);
    margin: 0 0 0.5rem;
}
.flc-card-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--flc-accent-hover);
    margin: 0;
}
.flc-card-sub {
    font-size: 0.85rem;
    color: var(--flc-text-secondary);
    margin: 0.25rem 0 0;
}

/* Result actions */
.flc-result-actions {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-bottom: 1.5rem;
}

/* Warnings */
.flc-warnings {
    background: rgba(245, 158, 11, 0.08);
    border-left: 3px solid var(--flc-warning);
    padding: 1rem;
    border-radius: var(--flc-radius);
    font-size: 0.9rem;
    color: var(--flc-text-secondary);
}
.flc-warning-message {
    margin: 0.25rem 0;
}

/* ---------- Sections ---------- */
.flc-section {
    margin-top: 2.5rem;
}
.flc-section-title {
    border-bottom: 1px solid var(--flc-border);
    padding-bottom: 0.5rem;
    margin-bottom: 1rem;
}

.flc-formula-box {
    background: var(--flc-surface);
    border: 1px solid var(--flc-border);
    border-radius: var(--flc-radius);
    padding: 1.2rem;
    font-family: monospace;
    color: var(--flc-accent-hover);
}

.flc-educational p, .flc-educational li {
    margin-bottom: 0.75rem;
}

/* FAQ */
.flc-faq-list dt {
    font-weight: 600;
    color: var(--flc-text);
    margin-top: 1rem;
}
.flc-faq-list dd {
    margin-left: 1rem;
    color: var(--flc-text-secondary);
    margin-bottom: 0.5rem;
}

/* Footer disclaimer */
.flc-disclaimer-footer {
    margin-top: 3rem;
    text-align: center;
    font-size: 0.8rem;
    color: var(--flc-text-secondary);
    border-top: 1px solid var(--flc-border);
    padding-top: 1rem;
}

/* ---------- Responsive ---------- */
@media (max-width: 600px) {
    .flc-tool {
        padding: 1rem;
    }
    .flc-mode-tabs {
        flex-direction: column;
    }
    .flc-inputs-grid {
        grid-template-columns: 1fr;
    }
    .flc-cards-grid {
        grid-template-columns: 1fr;
    }
}

/* ---------- Accessibility ---------- */
@media (prefers-reduced-motion: reduce) {
    .flc-tool * {
        transition-duration: 0.01ms !important;
    }
}