:root { 
        --org-color: #e67e22; 
        --text-main: #2c3e50; 
        --bg: #f4f7f6;
        --green-success: #27ae60;
        --blue-soft: #2980b9;
    }
    
    html { -webkit-text-size-adjust: 100%; }
    body { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; background: var(--bg); margin: 0; padding: 10px; padding: 10px max(10px, env(safe-area-inset-right)) max(10px, env(safe-area-inset-bottom)) max(10px, env(safe-area-inset-left)); -webkit-overflow-scrolling: touch; }
    .container { max-width: 850px; margin: 0 auto; }
    
    .logo-container { text-align: center; margin: 20px 0; }
    .logo-badge {
        display: inline-block; background: var(--org-color); color: white; padding: 12px 25px;
        border-radius: 50px 50px 5px 50px; font-weight: bold; font-size: 24px;
        box-shadow: 0 4px 15px rgba(0,0,0,0.15); border: 3px solid #2c3e50;
    }

    .molecule-display { 
        background: white; border: 2px solid #ddd; border-radius: 10px; 
        padding: 20px; margin: 20px 0; text-align: center;
        box-shadow: 0 4px 6px rgba(0,0,0,0.05);
        min-height: 250px;
        display: flex; align-items: center; justify-content: center;
        overflow-x: auto;
    }

    .card { background: white; padding: 20px; border-radius: 8px; box-shadow: 0 2px 10px rgba(0,0,0,0.1); }
    .btn { background: var(--org-color); color: white; border: none; padding: 12px 25px; border-radius: 5px; cursor: pointer; width: 100%; font-size: 1.1rem; margin-top: 10px; transition: 0.3s; touch-action: manipulation; -webkit-tap-highlight-color: transparent; }
    @media (hover:hover) { .btn:hover { opacity: 0.9; } }
    .organica-actions {
        display: grid;
        grid-template-columns: 1.4fr 1fr;
        gap: 10px;
        margin-top: 12px;
        align-items: stretch;
    }
    .organica-actions .btn { margin-top: 0; }
    .organica-actions .btn-tornar { background: #7f8c8d; }
    @media (max-width: 560px) {
        .organica-actions { grid-template-columns: 1fr; }
    }
    
    .menu-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 10px; margin-top: 20px; }
    .btn-menu { background: white; color: var(--org-color); border: 2px solid var(--org-color); font-weight: bold; padding: 15px 10px; border-radius: 8px; cursor: pointer; transition: 0.2s; touch-action: manipulation; -webkit-tap-highlight-color: transparent; }
    @media (hover:hover) { .btn-menu:hover { background: var(--org-color); color: white; } }
    .btn-menu.selected { background: var(--org-color); color: white; }
    
    .btn-start { background: var(--org-color); margin-top: 10px; font-weight: bold; font-size: 1.3rem; }
    
    input[type="text"] { width: 100%; padding: 12px; border: 2px solid #eee; border-radius: 5px; font-size: 1.1rem; box-sizing: border-box; }
    .feedback { margin-top: 15px; padding: 15px; border-radius: 5px; display: none; border: 1px solid #ddd; }
    .hidden { display: none !important; }
    .app-alert {
        position: fixed; top: 50%; left: 50%; transform: translate(-50%, -50%) scale(0.96);
        z-index: 10000; width: calc(100vw - 38px); max-width: 420px;
        background: rgba(255,255,255,0.98); color: #2c3e50; border: 1px solid #e4e9ec;
        border-radius: 18px;
        padding: 18px 18px 18px 48px; box-shadow: 0 18px 46px rgba(44,62,80,0.22);
        font-size: 1rem; line-height: 1.35; font-weight: 800;
        opacity: 0; pointer-events: none; transition: opacity 0.18s ease, transform 0.18s ease;
        text-align: left;
    }
    .app-alert.visible { opacity: 1; transform: translate(-50%, -50%) scale(1); pointer-events: auto; }
    .app-alert::before {
        content: "!"; position: absolute; left: 17px; top: 50%; transform: translateY(-50%);
        width: 22px; height: 22px; border-radius: 50%; background: var(--org-color); color: white;
        display: grid; place-items: center; font-weight: 900; font-size: 0.9rem;
    }
    .app-alert strong { display: none; }
    .app-alert-close {
        position: absolute;
        top: 10px;
        right: 10px;
        width: 30px;
        height: 30px;
        border: 0;
        border-radius: 999px;
        background: #eef2f4;
        color: var(--text-main);
        font-size: 1.2rem;
        font-weight: 900;
        line-height: 30px;
        cursor: pointer;
    }
    /* Selector de modalitat */
    .btn-mode {
        background: white; color: var(--text-main); border: 2px solid #ddd;
        border-radius: 10px; padding: 14px 10px; cursor: pointer; font-weight: bold;
        font-size: 1rem; display: flex; flex-direction: column; gap: 4px; line-height: 1.2;
        transition: 0.2s;
    }
    .btn-mode small { font-size: 0.72rem; font-weight: normal; color: #95a5a6; }
    .btn-mode.selected { border-color: var(--org-color); background: #fff5ec; color: var(--org-color); }
    .btn-mode.selected small { color: var(--org-color); }
    .config-subtitle {
        text-align: center;
        color: #7f8c8d;
        margin-top: 22px;
        margin-bottom: 10px;
        font-weight: 800;
        font-size: 1.05rem;
    }
    .isomeria-mode-grid {
        display: grid;
        grid-template-columns: repeat(2, minmax(0, 1fr));
        gap: 10px;
    }
    .difficulty-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
    .btn-difficulty {
        background: white; color: var(--text-main); border: 2px solid #ddd;
        border-radius: 9px; padding: 11px 6px; cursor: pointer; font-weight: bold;
        font-size: 0.9rem; transition: 0.2s; touch-action: manipulation;
        -webkit-tap-highlight-color: transparent;
    }
    .btn-difficulty.selected { border-color: var(--org-color); background: #fff5ec; color: var(--org-color); }
    @media (max-width: 520px) { .difficulty-grid { grid-template-columns: repeat(2, 1fr); } }

    .isomeria-enunciat {
        text-align: center;
        color: var(--text-main);
        font-weight: 700;
        margin: 6px 0 14px;
        line-height: 1.35;
    }
    .isomeria-parella {
        display: grid;
        grid-template-columns: repeat(2, minmax(0, 1fr));
        gap: 12px;
        margin-top: 10px;
    }
    .isomeria-mol h4 {
        margin: 0 0 6px;
        text-align: center;
        color: var(--org-color);
    }
    .isomeria-mol .molecule-display {
        min-height: 210px;
        margin: 0;
        padding: 12px;
    }
    .isomeria-respostes {
        display: grid;
        gap: 10px;
        margin-top: 14px;
        text-align: left;
    }
    .isomeria-respostes label {
        display: grid;
        gap: 5px;
        color: #566573;
        font-weight: 700;
        font-size: 0.9rem;
    }
    #isomeria-editor-area { margin: 10px 0; }
    #isomeria-dibuix-objectiu:empty { display: none; }
    .isomeria-afegits {
        margin-top: 12px;
        padding: 10px;
        border: 1px solid #e4e9ec;
        border-radius: 8px;
        background: #fafafa;
        color: #566573;
        font-size: 0.92rem;
    }
    .isomeria-afegits strong {
        display: block;
        color: var(--text-main);
        margin-bottom: 6px;
    }
    .isomeria-afegits ul {
        margin: 0;
        padding-left: 18px;
    }
    .isomeria-afegits li { margin: 3px 0; }
    @media (max-width: 680px) {
        .isomeria-parella { grid-template-columns: 1fr; }
        .isomeria-mode-grid { grid-template-columns: 1fr; }
    }

    /* Editor de dibuix */
    #editor-area { margin: 10px 0; }
    .ed-lienzo { background: #fafafa; border: 2px solid #ddd; border-radius: 10px; width: 100%; height: 300px; touch-action: manipulation; display: block; }
    .ed-seccio-titol { font-size: 0.8rem; font-weight: bold; color: #7f8c8d; margin: 12px 0 5px 0; text-transform: uppercase; letter-spacing: 0.5px; }
    .ed-paleta { display: flex; flex-wrap: wrap; gap: 6px; }
    .ed-chip {
        border: 2px solid #ccc; background: white; border-radius: 18px; padding: 7px 12px;
        font-size: 0.9rem; cursor: pointer; font-weight: bold; color: var(--text-main); transition: 0.15s;
    }
    .ed-chip.sel { background: var(--org-color); color: white; border-color: var(--org-color); }
    .ed-chip.esq { border-color: var(--blue-soft); color: var(--blue-soft); }
    .ed-chip.esq.sel { background: var(--blue-soft); color: white; }
    .ed-toolbar { display:flex; gap:6px; flex-wrap:wrap; margin-bottom:8px; }
    .ed-toolbar button { flex:1; min-width: 90px; border:2px solid #ddd; background:white; border-radius:8px; padding:9px 6px; font-weight:bold; cursor:pointer; font-size:0.85rem; }
    .ed-hint { font-size: 0.75rem; color: #95a5a6; text-align: center; margin-top: 6px; }

    /* Editor integrat (del playground) */
    .seccio { font-size:0.78rem; font-weight:bold; color:#7f8c8d; margin:14px 0 6px; text-transform:uppercase; letter-spacing:0.5px; }
    .toolbar { display:flex; gap:6px; flex-wrap:wrap; }
    .toolbar button { flex:1; min-width:80px; border:2px solid #ddd; background:white; border-radius:8px; padding:10px 6px; font-weight:bold; cursor:pointer; font-size:0.85rem; transition:0.15s; }
    .toolbar button:active { transform:scale(0.96); }
    .toolbar button.selected-tool { background:#f39c12; border-color:#e67e22; color:white; }
    .toolbar button.danger { border-color:#e74c3c; color:#e74c3c; }
    .sizes { display:flex; gap:6px; flex-wrap:wrap; margin-top:8px; }
    .sizes button { border:2px solid #ccc; background:white; border-radius:8px; padding:8px 0; cursor:pointer; font-weight:bold; min-width:42px; }
    .sizes button.on { background:var(--text-main); color:white; border-color:var(--text-main); }
    .paleta { display:flex; flex-wrap:wrap; gap:6px; }
    .chip { border:2px solid #ccc; background:white; border-radius:18px; padding:8px 13px; font-size:0.9rem; cursor:pointer; font-weight:bold; transition:0.15s; }
    .chip.sel { background:var(--org-color); color:white; border-color:var(--org-color); }
    .chip.opcio-selector-triada { background:#000; color:white; border-color:#000; }
    .chip.esq { border-color:var(--blue-soft); color:var(--blue-soft); }
    .chip.esq.sel { background:var(--blue-soft); color:white; }
    .chip.ele { border-color:var(--green-success); color:var(--green-success); }
    .chip.ele.sel { background:var(--green-success); color:white; }
    .btn-val { background:var(--green-success); }
    .btn-sec { background:#95a5a6; margin-top:8px; color:white; }
    .pregunta-topline {
        display: flex;
        align-items: center;
        justify-content: space-between;
        gap: 10px;
        margin-bottom: 10px;
    }
    .pregunta-info-text {
        font-weight: 900;
        color: #7f8c8d;
        font-size: 0.9rem;
        letter-spacing: 0.03em;
    }
    .consulta-grups-slot {
        display: flex;
        align-items: center;
        justify-content: flex-end;
        gap: 7px;
        flex-wrap: wrap;
        flex: 0 0 auto;
    }
    .consulta-grups-btn {
        border: 0;
        border-radius: 999px;
        background: var(--org-color);
        color: white;
        padding: 8px 13px;
        font-weight: 900;
        box-shadow: 0 3px 10px rgba(0,0,0,0.14);
        cursor: pointer;
        font-size: 0.84rem;
    }
    .btn-help-answer {
        padding: 0;
        min-height: 40px;
        background: #fff4e7;
        color: var(--org-color);
        border: 2px solid #f3d3ae;
        border-radius: 12px;
        font-size: 1.15rem;
        font-weight: 900;
    }
    .pregunta-help-btn {
        width: 40px;
        height: 40px;
        min-height: 40px;
        flex: 0 0 auto;
        cursor: pointer;
    }
    .consulta-prefixos-btn { background: var(--blue-soft); }
    .consulta-isomeria-btn { background: #16a085; }
    .consulta-grups-card.consulta-prefixos-card {
        width: 260px;
        max-width: calc(100vw - 28px);
        box-sizing: border-box;
    }
    .consulta-prefixos-card .consulta-ajuda-nota { max-width: 206px; }
    .consulta-isomeria-card { width: min(100%, 620px); }
    .consulta-isomeria-body {
        display: grid;
        gap: 12px;
        text-align: left;
        color: #2c3e50;
    }
    .consulta-isomeria-body h3 {
        margin: 0 0 4px;
        color: var(--org-color);
        font-size: 1rem;
    }
    .consulta-isomeria-body p {
        margin: 0;
        color: #566573;
        line-height: 1.35;
    }
    .consulta-isomeria-table {
        margin-top: 6px;
        min-width: 0;
    }
    .consulta-ajuda-nota {
        margin: -6px 42px 12px 0;
        color: #7f8c8d;
        font-size: 0.88rem;
        font-weight: 700;
    }
    .consulta-grups-table.consulta-prefixos-table {
        min-width: 0 !important;
        width: 100% !important;
        margin: 0 auto;
        table-layout: fixed;
    }
    .consulta-grups-table.consulta-prefixos-table td,
    .consulta-grups-table.consulta-prefixos-table th {
        text-align: center;
        padding-left: 14px;
        padding-right: 14px;
    }
    @media (max-width: 520px) {
        .pregunta-topline { align-items: flex-start; }
        .consulta-grups-btn { padding: 7px 11px; font-size: 0.8rem; }
    }
    .consulta-grups-modal {
        position: fixed;
        inset: 0;
        z-index: 11000;
        display: none;
        align-items: center;
        justify-content: center;
        padding: 14px;
        background: rgba(44,62,80,0.42);
    }
    .consulta-grups-modal.visible { display: flex; }
    .consulta-grups-card {
        position: relative;
        width: min(100%, 900px);
        max-height: min(88vh, 720px);
        background: white;
        border-radius: 18px;
        padding: 18px;
        box-shadow: 0 20px 54px rgba(44,62,80,0.25);
        border: 1px solid #edf1ef;
    }
    .consulta-grups-card h2 {
        margin: 0 42px 14px 0;
        color: var(--org-color);
        font-size: 1.25rem;
    }
    .consulta-grups-close {
        position: absolute;
        top: 12px;
        right: 12px;
        width: 32px;
        height: 32px;
        border: 0;
        border-radius: 999px;
        background: #eef2f4;
        color: var(--text-main);
        font-size: 1.25rem;
        font-weight: 900;
        cursor: pointer;
        line-height: 32px;
    }
    .consulta-grups-scroll {
        overflow: auto;
        max-height: calc(min(88vh, 720px) - 78px);
        -webkit-overflow-scrolling: touch;
    }
    .consulta-grups-table {
        width: 100%;
        border-collapse: collapse;
        min-width: 820px;
        font-size: 0.9rem;
    }
    .consulta-grups-table th,
    .consulta-grups-table td {
        padding: 9px 8px;
        border-bottom: 1px solid #edf1ef;
        text-align: left;
        vertical-align: top;
    }
    .consulta-grups-table th {
        position: sticky;
        top: 0;
        background: #fff6ed;
        color: var(--org-color);
        z-index: 1;
        font-size: 0.78rem;
        text-transform: uppercase;
        letter-spacing: 0.04em;
    }
    .fg-rep {
        display: inline-block;
        background: #f8fafb;
        border: 1px solid #e5ece8;
        border-radius: 999px;
        padding: 4px 8px;
        font-family: "Segoe UI", sans-serif;
        font-weight: 900;
        white-space: nowrap;
    }
    .fg-reps {
        display: flex;
        align-items: center;
        gap: 5px;
        flex-wrap: wrap;
    }
    .fg-rep-sep {
        color: #95a5a6;
        font-weight: 900;
    }
    .fg-dibuix {
        display: inline-flex;
        align-items: center;
        justify-content: center;
        background: #fff;
        border: 1px solid #e5ece8;
        border-radius: 12px;
        padding: 2px 5px;
    }
    .fg-svg {
        width: 118px;
        height: 56px;
        display: block;
    }
    .fg-svg line {
        stroke: var(--text-main);
        stroke-width: 2.3;
        stroke-linecap: round;
    }
    .fg-svg text {
        fill: var(--text-main);
        font: 800 13px "Segoe UI", Tahoma, sans-serif;
    }
    .nota-consultes-organica {
        background: #fff6ed;
        border: 1px solid #f3d3b5;
        border-radius: 12px;
        padding: 10px;
        margin: 12px 0 18px;
        color: #8a5a28;
        font-weight: 800;
        font-size: 0.95rem;
    }

    /* Tots els botons capturen bé el toc a iOS (sense doble pulsació) */
    button, .chip, .btn, .btn-menu, .toolbar button, .sizes button {
      touch-action: manipulation;
      -webkit-tap-highlight-color: transparent;
    }

    /* Manté àtoms, subíndexs i enllaços sobre el mateix eix visual. */
    .molecula-grid > div { line-height: 1; }
    .molecula-grid sub {
        font-size: 0.65em;
        line-height: 0;
        vertical-align: baseline;
        position: relative;
        bottom: -0.38em;
    }
    .molecula-grid svg { display: block; }
    .molecula-grid svg.enllac-multiple { transform: translateY(-2px); }
    .molecula-scroll {
        width: 100%;
        overflow-x: auto;
        overflow-y: visible;
        padding: 8px 0 12px;
        -webkit-overflow-scrolling: touch;
    }
    .molecula-scroll.benze-radical-vertical {
        padding-top: 95px;
        padding-bottom: 55px;
    }
    .molecula-scroll.cicle-radical-llarg {
        overflow-x: auto;
        padding-top: 110px;
        padding-left: 95px;
        padding-right: 120px;
        padding-bottom: 75px;
        box-sizing: border-box;
    }
    .molecula-scroll > .molecula-grid { margin-left: auto; margin-right: auto; }