/*!
 * Stradella Explorer — Styles
 * Copyright (c) 2026 Giovanni Lucifero. All rights reserved.
 * Part of accordionchords.com
 *
 * This source code is proprietary. No part of it may be copied, reproduced,
 * modified, distributed, or used to create derivative works without the prior
 * written permission of the copyright holder.
 */

/* ── TOKENS (Grigio Antracite / Dark Mode Pura) ────────── */
        :root {
            --ac-orange:       #ff8c42;
            --ac-orange-dim:   rgba(255, 140, 66, 0.22);
            --ac-orange-glow:  rgba(255, 140, 66, 0.16);
            --ac-green:        #19FF18;
            --ac-green-glow:   rgba(25, 255, 24, 0.75);
            --ac-white-glow:   rgba(255, 255, 255, 0.28);
            
            /* Sfondi (Grigio scuro puro, niente marrone) */
            --ac-panel:        #1e1e1e;
            --ac-board:        #121212;
            
            /* Bordi (Grigio medio) */
            --ac-border:       #333333;
            --ac-border-lt:    #444444;
            
            /* Testi (Scala di grigi pulita) */
            --ac-text:         #f0f0f0;
            --ac-secondary:    #aaaaaa;
            --ac-muted:        #777777;
            --ac-dim:          #444444;
        }

        /* ── APP SHELL ────────────────────────────────────────────────── */
        #stradella-app {
            font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
            color: var(--ac-text); max-width: 1060px; margin: 0 auto;
            box-sizing: border-box;
            -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale;
        }
        #stradella-app .main-layout {
            display: flex; flex-wrap: wrap; gap: 18px;
            justify-content: center; align-items: flex-start;
        }
        #stradella-app .board-wrapper { display: flex; flex-direction: column; align-items: center; }

        /* Boards tight around buttons; console wider */
        #stradella-app .board-container { width: 250px; box-sizing: border-box; }
        #stradella-app .center-console  { width: 296px; box-sizing: border-box; }

        /* ── BOARD ────────────────────────────────────────────────────── */
        #stradella-app .board-container {
            background: radial-gradient(ellipse at 40% 0%, #2b2b2b, var(--ac-board));
            padding: 16px 10px; border-radius: 14px;
            display: flex; justify-content: center; gap: 4px;
            box-shadow: 0 0 0 1px var(--ac-border), 0 16px 48px rgba(0,0,0,0.8),
                        inset 0 1px 0 rgba(255,255,255,0.025);
        }
        #stradella-app .board-title {
            font-size: 10px; color: var(--ac-muted); text-transform: uppercase;
            letter-spacing: 4px; margin-bottom: 12px; font-weight: 700;
        }
        #stradella-app .stradella-col { display: flex; flex-direction: column; align-items: center; gap: 2px; }
        #stradella-app .col-title {
            font-size: 8px; color: var(--ac-secondary); font-weight: 700;
            text-transform: uppercase; letter-spacing: 0.7px;
            margin-bottom: 6px; height: 12px; line-height: 12px;
        }

        /* ── BUTTONS -- OFF (Luce frontale/diagonale morbida) ────────────────────── */
        #stradella-app .btn-bass,
        #stradella-app .btn-chord {
            width: 35px !important; height: 35px !important;
            min-width: 35px !important; min-height: 35px !important;
            border-radius: 50% !important; position: relative !important;
            background: radial-gradient(circle at 25% 25%, #7a7a7a, #333333) !important;
            display: flex !important; flex-direction: column !important;
            align-items: center !important; justify-content: center !important;
            cursor: pointer !important; user-select: none !important;
            transition: all 0.15s ease !important;
            padding: 0 !important; margin: 0 !important; border: none !important;
            box-shadow: 
                2px 3px 5px rgba(0,0,0,0.5), 
                inset 1px 1px 2px rgba(255,255,255,0.15), 
                inset -2px -2px 4px rgba(0,0,0,0.5) !important;
        }

        #stradella-app .btn-note {
            font-weight: 600 !important; font-size: 13px !important;  
            letter-spacing: -0.2px !important; margin: 0 !important; padding: 0 !important;
            line-height: 1.1 !important; display: block !important; 
            color: #ffffff !important; text-shadow: 0 -1px 2px rgba(0,0,0,0.8) !important; 
        }
        #stradella-app .btn-type {
            font-size: 8px !important; font-weight: 500 !important;       
            color: #d4d4d4 !important; text-transform: uppercase !important; 
            letter-spacing: 0.5px !important; margin: 1px 0 0 !important; padding: 0 !important;
            line-height: 1 !important; display: block !important;
        }

        #stradella-app .btn-bass:hover,
        #stradella-app .btn-chord:hover { 
            background: radial-gradient(circle at 25% 25%, #858585, #3d3d3d) !important;
            transform: translateY(-1px) !important; 
        }

        #stradella-app .btn-c-ref::after {
            content: ''; position: absolute; bottom: 3px; left: 50%; transform: translateX(-50%);
            width: 5px; height: 5px; border-radius: 50%;
            background: radial-gradient(circle at 30% 30%, #fff 20%, #aaa);
            box-shadow: 1px 1px 2px rgba(0,0,0,0.6); pointer-events: none;
        }

        /* ── CHORD ACTIVE ──────────────────────────── */
        #stradella-app .btn-chord.active {
            background: radial-gradient(circle at 25% 25%, #70ff6e, var(--ac-green)) !important;
            border: none !important;
            box-shadow: 
                0 0 16px var(--ac-green-glow), 
                2px 3px 5px rgba(0,0,0,0.5),
                inset 1px 1px 2px rgba(255,255,255,0.4), 
                inset -2px -2px 4px rgba(0,100,0,0.4) !important;
            transform: translateY(1px) !important;
        }
        #stradella-app .btn-chord.active .btn-note { color: #003300 !important; text-shadow: 0 1px 1px rgba(255,255,255,0.4) !important; }
        #stradella-app .btn-chord.active .btn-type { color: #004d00 !important; }

        /* ── ROOT ACTIVE ───────────────── */
        #stradella-app .btn-bass.active {
            background: radial-gradient(circle at 25% 25%, #8a8a8a, #4a4a4a) !important;
            border: 2px solid #ffffff !important; 
            transform: translateY(1px) !important;
            box-shadow: 
                0 0 16px var(--ac-white-glow), 
                2px 3px 5px rgba(0,0,0,0.5),
                inset 1px 1px 2px rgba(255,255,255,0.3), 
                inset -2px -2px 4px rgba(0,0,0,0.6) !important;
        }
        #stradella-app.has-active-roots .btn-bass:not(.active) {
            opacity: 0.5 !important; filter: saturate(0.2) brightness(0.8) !important;
        }

        /* ══════════════════════════════════════════════════════════════
           CENTER CONSOLE
        ══════════════════════════════════════════════════════════════════ */
        #stradella-app .center-console {
            background: var(--ac-panel); border-radius: 14px; border: 1px solid var(--ac-border);
            min-height: 480px; display: flex; flex-direction: column; overflow: hidden;
            box-shadow: 0 0 0 1px rgba(255,255,255,0.02), 0 20px 60px rgba(0,0,0,0.65);
            align-self: center;
        }
        #stradella-app .tabs-header { display: flex; background: var(--ac-board); border-bottom: 1px solid var(--ac-border); }
        #stradella-app .tab-btn {
            flex: 1; padding: 15px 0; background: transparent; color: var(--ac-muted);
            border: none; border-bottom: 2px solid transparent;
            font-size: 10px; font-weight: 700; text-transform: uppercase; letter-spacing: 2px;
            cursor: pointer; transition: 0.2s;
        }
        #stradella-app .tab-btn:hover { color: var(--ac-text); }
        #stradella-app .tab-btn.active {
            color: var(--ac-orange); border-bottom: 2px solid var(--ac-orange);
            background: rgba(255,140,66,0.05);
        }
        #stradella-app .tab-content {
            padding: 20px 16px; display: none;
            flex-direction: column; align-items: center; flex: 1; text-align: center;
        }
        #stradella-app .tab-content.active { display: flex; animation: fadeIn 0.25s ease; }
        @keyframes fadeIn { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: translateY(0); } }
        #stradella-app .panel-header {
            font-size: 9px; text-transform: uppercase; letter-spacing: 3px;
            color: var(--ac-muted); margin-bottom: 14px; font-weight: 700;
            border-bottom: 1px solid var(--ac-border); width: 100%; padding-bottom: 8px;
        }

        /* ── COMBINATOR ───────────────────────────────────────────────── */
        #stradella-app .chord-name {
            font-size: 28px; font-weight: 900; color: var(--ac-orange);
            margin-bottom: 10px; line-height: 1.2; letter-spacing: -0.5px;
            transition: font-size 0.15s;
        }
        #stradella-app .chord-play-row {
            display: grid; grid-template-columns: 46px 1fr 46px;
            align-items: center; width: 100%; margin-bottom: 12px;
        }
        #stradella-app .chord-play-row .chord-name { margin-bottom: 0; }
        #stradella-app .chord-play-row .play-btn   { justify-self: end; }
        #stradella-app .chord-name a { color: inherit; text-decoration: none; cursor: pointer; border-bottom: 2px dotted rgba(255,140,66,0.5); }
        #stradella-app .chord-name a:hover { border-bottom-color: var(--ac-orange); text-decoration: underline; text-underline-offset: 4px; }
        #stradella-app .chord-secondary {
            display: none; font-size: 12.5px; color: var(--ac-muted);
            margin: -4px 0 12px; line-height: 1.4; letter-spacing: 0.1px;
        }
        #stradella-app .chord-secondary strong { color: #9aa7b4; font-weight: 700; }
        #stradella-app .chord-secondary-list {
            list-style: none; margin: 0; padding: 0;
        }
        #stradella-app .chord-secondary-list li {
            position: relative; padding-left: 16px; margin: 2px 0;
        }
        #stradella-app .chord-secondary-list li::before {
            content: "\2022"; position: absolute; left: 2px; color: var(--ac-muted);
        }
        #stradella-app .combo-inversion {
            display: none; font-size: 12.5px; color: var(--ac-muted);
            margin: 4px 0 0; line-height: 1.4; letter-spacing: 0.1px;
        }
        #stradella-app .combo-inversion strong { color: #9aa7b4; font-weight: 700; }
        #stradella-app #find-quality option.q-unreachable,
        #stradella-app #find-root option.q-unreachable {
            color: #8a7a5c; font-style: italic; opacity: 0.72;
        }

        /* INTERVAL PILLS */
        #stradella-app .intervals-list {
            display: flex; flex-wrap: wrap; gap: 5px;
            justify-content: center; margin-bottom: 12px; width: 100%;
        }
        #stradella-app .interval-pill {
            background: var(--ac-panel); border: 1px solid var(--ac-border-lt);
            border-radius: 20px; padding: 5px 11px;
            font-size: 12px; font-weight: 600; color: var(--ac-text);
            display: flex; align-items: center; gap: 5px;
        }
        #stradella-app .interval-pill span.note { color: var(--ac-orange); font-size: 13px; font-weight: 800; }

        #stradella-app .omitted-note {
            font-size: 12px; color: var(--ac-secondary); margin-top: 6px;
            padding: 4px 10px; border-radius: 4px;
            border: 1px solid var(--ac-border); background: rgba(255,255,255,0.025);
        }

        /* DISCLAIMER / WARNING */
        #stradella-app .cluster-warning {
            position: relative;
            border-radius: 8px;
            padding: 11px 14px 11px 16px;
            font-size: 11.5px;
            margin: 8px 0 14px 0; text-align: left; display: none;
            line-height: 1.55; width: 100%; box-sizing: border-box;
            border: 1px solid transparent;
            border-left-width: 3px;
            backdrop-filter: blur(2px);
            animation: sa-warn-in 0.28s cubic-bezier(0.16, 1, 0.3, 1);
        }
        @keyframes sa-warn-in {
            from { opacity: 0; transform: translateY(-3px); }
            to   { opacity: 1; transform: translateY(0); }
        }
        #stradella-app .cluster-warning strong {
            font-weight: 600; letter-spacing: 0.01em;
        }
        /* 🚫 AVOID — red */
        #stradella-app .cluster-warning.w-avoid {
            background: linear-gradient(100deg, rgba(255,68,68,0.12) 0%, rgba(255,68,68,0.04) 60%);
            border-color: rgba(255,68,68,0.30);
            border-left-color: #ff4444;
            color: #ffb4b4;
        }
        #stradella-app .cluster-warning.w-avoid strong { color: #ff6b6b; }
        /* ⚠️ CAUTION — amber */
        #stradella-app .cluster-warning.w-caution {
            background: linear-gradient(100deg, rgba(251,146,60,0.12) 0%, rgba(251,146,60,0.04) 60%);
            border-color: rgba(251,146,60,0.30);
            border-left-color: #fb923c;
            color: #fcd9ab;
        }
        #stradella-app .cluster-warning.w-caution strong { color: #fdac5c; }
        /* 💡 NOTE — blue */
        #stradella-app .cluster-warning.w-note {
            background: linear-gradient(100deg, rgba(96,165,250,0.11) 0%, rgba(96,165,250,0.035) 60%);
            border-color: rgba(96,165,250,0.26);
            border-left-color: #60a5fa;
            color: #c6dcfb;
        }
        #stradella-app .cluster-warning.w-note strong { color: #93c5fd; }

        /* PLAY BUTTON */
        #stradella-app .play-btn {
            background: rgba(255,140,66,0.10); border: 1px solid rgba(255,140,66,0.30);
            border-radius: 50%; width: 42px; height: 42px;
            cursor: pointer; font-size: 0;
            display: flex; align-items: center; justify-content: center;
            flex-shrink: 0; opacity: 0.65; transition: opacity 0.18s, background 0.18s;
        }
        #stradella-app .play-btn::before {
            content: ''; display: block; width: 0; height: 0;
            border-style: solid; border-width: 7px 0 7px 13px;
            border-color: transparent transparent transparent var(--ac-orange);
            margin-left: 3px; transition: border-color 0.18s;
        }
        #stradella-app .play-btn:not(:disabled):hover {
            background: var(--ac-orange); opacity: 1;
            box-shadow: 0 0 14px rgba(255,140,66,0.45);
        }
        #stradella-app .play-btn:not(:disabled):hover::before { border-left-color: #fff; }
        
        /* Cursor fix per browser moderni */
        #stradella-app .play-btn:disabled {
            opacity: 0.18; cursor: not-allowed; background: none; border-color: var(--ac-border);
        }
        #stradella-app .play-btn:disabled::before { border-left-color: var(--ac-muted); }

        /* Stato di caricamento samples: spinner */
        #stradella-app .play-btn.loading {
            opacity: 0.9 !important;
            cursor: wait !important;
            background: rgba(255,140,66,0.08) !important;
            border-color: rgba(255,140,66,0.4) !important;
        }
        #stradella-app .play-btn.loading::before {
            content: '' !important;
            width: 13px !important; height: 13px !important;
            border-style: solid !important;
            border-width: 2px !important;
            border-color: rgba(255,140,66,0.22) rgba(255,140,66,0.22) rgba(255,140,66,0.22) var(--ac-orange) !important;
            border-radius: 50% !important;
            margin-left: 0 !important;
            animation: spl-spin 0.75s linear infinite !important;
        }
        @keyframes spl-spin { to { transform: rotate(360deg); } }

        /* ACTION BUTTON */
        #stradella-app .action-btn {
            background: linear-gradient(135deg, var(--ac-orange), #d96508);
            color: #fff; border: none; padding: 13px 18px; border-radius: 8px;
            cursor: pointer; width: 100%; font-weight: 800;
            text-transform: uppercase; letter-spacing: 1.5px; font-size: 11px;
            margin-top: auto; transition: 0.2s; box-shadow: 0 4px 14px rgba(255,140,66,0.24);
        }
        #stradella-app .action-btn:hover { filter: brightness(1.08); transform: translateY(-1px); box-shadow: 0 7px 20px rgba(255,140,66,0.35); }
        #stradella-app .action-btn:active { transform: translateY(1px); }

        /* ── FINDER SELECTS ───────────────────────────────────────────── */
        #stradella-app .select-group { width: 100%; margin-bottom: 10px; }
        #stradella-app .finder-select {
            width: 100%; padding: 10px 32px 10px 12px;
            background: var(--ac-board) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6'%3E%3Cpath d='M0 0l5 6 5-6z' fill='%23777777'/%3E%3C/svg%3E") no-repeat right 12px center;
            color: var(--ac-text); border: 1px solid var(--ac-border);
            border-radius: 8px; font-size: 13px; font-weight: 600;
            appearance: none; cursor: pointer;
        }
        #stradella-app .finder-select:focus { outline: none; border-color: var(--ac-orange); box-shadow: 0 0 0 3px var(--ac-orange-dim); }
        #stradella-app .finder-select optgroup { background: #111; color: var(--ac-orange); font-weight: 700; }
        #stradella-app .finder-select option  { background: var(--ac-panel); color: var(--ac-text); }

        /* ══════════════════════════════════════════════════════════════
           FINDER RESULTS
        ══════════════════════════════════════════════════════════════════ */
        #finder-results {
            background: var(--ac-board); border: 1px solid var(--ac-border-lt);
            border-top: 2px solid var(--ac-orange); border-radius: 8px;
            padding: 14px 14px 12px; box-sizing: border-box;
            box-shadow: 0 0 0 1px var(--ac-orange-glow), inset 0 0 28px rgba(0,0,0,0.5);
            width: 100%; margin-top: 12px; display: none;
        }

        /* NAV */
        #stradella-app .finder-topbar {
            display: flex; flex-direction: column; align-items: center; gap: 4px;
            margin-bottom: 12px; padding-bottom: 10px;
            border-bottom: 1px solid var(--ac-border);
        }
        #stradella-app .finder-nav-full { display: flex; align-items: center; gap: 6px; }
        #stradella-app .nav-btn-sm {
            background: transparent; color: var(--ac-secondary);
            border: 1px solid var(--ac-border-lt); border-radius: 5px;
            width: 24px; height: 24px; font-size: 10px; cursor: pointer;
            display: flex; align-items: center; justify-content: center;
            transition: 0.15s; padding: 0; flex-shrink: 0;
        }
        #stradella-app .nav-btn-sm:hover:not(:disabled) { color: var(--ac-orange); border-color: var(--ac-orange); box-shadow: 0 0 6px var(--ac-orange-dim); }
        #stradella-app .nav-btn-sm:disabled { color: var(--ac-dim); border-color: var(--ac-dim); cursor: not-allowed; }
        #combo-counter { font-size: 13px; font-weight: 800; color: var(--ac-text); min-width: 42px; text-align: center; }
        #stradella-app .nav-sep { display: none; }
        #find-status { font-size: 10px; color: var(--ac-muted); font-weight: 600; letter-spacing: 0.4px; white-space: nowrap; }

        /* CHORD HEADER */
        #stradella-app .finder-chord-header { display: flex; align-items: center; justify-content: center; gap: 8px; margin-bottom: 4px; }
        #combo-desc { font-size: 21px !important; font-weight: 900 !important; color: #ffffff !important; text-align: center !important; line-height: 1.2 !important; transition: font-size 0.15s; }
        #combo-desc a { color: #ffffff !important; text-decoration: none !important; }
        #combo-desc a:hover { text-decoration: underline !important; }
        #combo-sub { font-size: 12px !important; color: var(--ac-secondary) !important; text-align: center !important; margin-bottom: 10px !important; }

        /* DIVIDERS */
        #stradella-app .finder-divider { border: none; border-top: 1px solid var(--ac-border); margin: 10px 0; }

        /* CONTRIBUTION MAP */
        #stradella-app #display-contribution:not(:empty),
        #stradella-app #combo-contribution:not(:empty) {
            margin-bottom: 18px;
        }
        #stradella-app .btn-contribution {
            display: flex; justify-content: center; align-items: flex-start;
            flex-wrap: wrap; gap: 6px; width: 100%; padding: 4px 0 2px;
        }
        #stradella-app .bc-source { display: flex; flex-direction: column; align-items: center; gap: 5px; }
        #stradella-app .bc-lbl { font-size: 9.5px; color: var(--ac-secondary); text-align: center; white-space: nowrap; font-weight: 600; }
        #stradella-app .bc-notes { display: flex; gap: 3px; }
        #stradella-app .bc-note {
            background: var(--ac-panel); border: 1px solid var(--ac-border-lt); border-radius: 4px;
            padding: 5px 8px; font-size: 11px; font-weight: 700; color: var(--ac-text);
            min-width: 28px; text-align: center;
        }
        #stradella-app .bc-note.shared { background: rgba(25,255,24,0.09); border-color: rgba(25,255,24,0.38); color: #5fdf5e; }
        #stradella-app .bc-sep { color: var(--ac-dim); font-size: 16px; margin-top: 18px; align-self: flex-start; padding: 0 1px; user-select: none; }

        /* KBD HINT */
        #stradella-app .kbd-hint { font-size: 10px; color: var(--ac-dim); margin-top: 10px; text-align: center; }
        #stradella-app .kbd-hint kbd { background: var(--ac-panel); border: 1px solid var(--ac-border); border-radius: 3px; padding: 1px 4px; font-size: 9px; color: var(--ac-muted); }

        /* ── FRENCH LAYOUT TOGGLE ────────────────────────────────── */
        #stradella-app .french-toggle {
            text-align: center; margin-bottom: 14px; display: none;
        }
        #stradella-app .french-toggle label {
            display: inline-flex; align-items: center; gap: 8px;
            font-size: 10px; font-weight: 700; letter-spacing: 0.4px;
            text-transform: uppercase; cursor: pointer; transition: 0.15s;
            color: #cccccc; background: #2a2a2a; border: 1px solid #666666;
            border-radius: 20px; padding: 6px 16px; user-select: none;
        }
        #stradella-app .french-toggle label:hover {
            background: #383838; border-color: #999999; color: #ffffff;
        }
        #stradella-app .french-toggle.active label {
            background: #3d1f05; border-color: #ff8c42; color: #ff8c42;
        }
        #stradella-app .french-toggle.active label:hover {
            background: #4d2808; border-color: #ffaa66; color: #ffaa66;
        }
        #stradella-app .french-toggle input[type=checkbox] { accent-color: #ff8c42; width: 13px; height: 13px; cursor: pointer; }

        /* ── SIZE SELECTOR ───────────────────────────────────────── */
        #stradella-app .size-selector {
            display: flex; justify-content: center; flex-wrap: wrap;
            gap: 5px; margin-bottom: 12px;
        }
        #stradella-app .size-btn {
            background: #2a2a2a; border: 1px solid #555555;
            color: #cccccc; border-radius: 20px;
            padding: 5px 11px; font-size: 10px; font-weight: 700;
            letter-spacing: 0.5px; cursor: pointer; transition: 0.15s;
            text-transform: uppercase; white-space: nowrap;
        }
        #stradella-app .size-btn:hover { background: #383838; border-color: #999999; color: #ffffff; }
        #stradella-app .size-btn.active { background: #3d1f05; border-color: #ff8c42; color: #ff8c42; }
        #stradella-app .size-btn.active:hover { background: #4d2808; border-color: #ffaa66; color: #ffaa66; }

        /* article-btn hidden */
        #stradella-app .article-btn { display: none !important; }

        /* ── CHORDSAROUND INVITE LINK ─────────────────────────────── */
        #stradella-app .ca-invite {
            font-size: 11px; color: var(--ac-secondary);
            text-align: center; margin-top: 10px; display: none;
            font-style: italic; width: 100%; line-height: 1.4;
        }
        #stradella-app .ca-invite a {
            color: var(--ac-secondary); text-decoration: none;
            border-bottom: 1px dotted var(--ac-muted);
            transition: color 0.15s;
        }
        #stradella-app .ca-invite a:hover { color: var(--ac-text); border-bottom-color: var(--ac-text); }

        /* ── APP CREDITS / FOOTER ────────────────────────────────── */
        #stradella-app .app-credits {
            text-align: center;
            font-size: 10px;
            color: var(--ac-muted);
            margin-top: 24px;
            padding-top: 12px;
            border-top: 1px solid var(--ac-border);
            width: 100%;
        }
        #stradella-app .app-credits a {
            color: var(--ac-secondary);
            text-decoration: none;
            border-bottom: 1px dotted var(--ac-muted);
            transition: color 0.15s, border-color 0.15s;
        }
        #stradella-app .app-credits a:hover {
            color: var(--ac-orange);
            border-bottom-color: var(--ac-orange);
        }


/* ===== EXPLANATORY TEXTS ===== */
/* A1 — intro above the size selector (unframed text on the page background) */
#stradella-app .sa-intro {
    width: 832px;
    max-width: 100%;
    margin: 0 auto 18px auto;
    padding: 0 8px;
    font-size: 14px;
    line-height: 1.6;
    color: #3a3633;
    text-align: center;
    box-sizing: border-box;
}
#stradella-app .sa-intro strong { color: #b5500c; font-weight: 600; }

/* B — teaching section below the app */
#stradella-app .sa-guide {
    width: 832px;
    max-width: 100%;
    margin: 36px auto 8px auto;
    padding: 28px 34px;
    background: linear-gradient(90deg, #1a1a1a 0%, #2b2b2b 50%, #1a1a1a 100%);
    border: 1px solid var(--ac-border);
    border-radius: 14px;
    box-shadow: 0 0 0 1px var(--ac-border), 0 16px 48px rgba(0,0,0,0.8),
                inset 0 1px 0 rgba(255,255,255,0.025);
    text-align: left;
    box-sizing: border-box;
}
#stradella-app .sa-guide-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--ac-text);
    margin: 0 0 6px 0;
    letter-spacing: 0.01em;
}
#stradella-app .sa-guide h3 {
    font-size: 14.5px;
    font-weight: 600;
    color: var(--ac-orange);
    margin: 24px 0 7px 0;
    letter-spacing: 0.01em;
}
#stradella-app .sa-guide h3:first-child { margin-top: 0; }
#stradella-app .sa-guide p {
    font-size: 13.5px;
    line-height: 1.68;
    color: var(--ac-secondary);
    margin: 0 0 10px 0;
}
#stradella-app .sa-guide strong { color: var(--ac-text); font-weight: 600; }
#stradella-app .sa-guide em { color: var(--ac-text); font-style: italic; }

/* How-to list inside the guide */
#stradella-app .sa-howto {
    list-style: none;
    margin: 0 0 10px 0;
    padding: 0;
}
#stradella-app .sa-howto li {
    font-size: 13.5px;
    line-height: 1.6;
    color: var(--ac-secondary);
    padding: 3px 0 3px 16px;
    position: relative;
}
#stradella-app .sa-howto li::before {
    content: "\203A";
    position: absolute;
    left: 0;
    color: var(--ac-orange);
    font-weight: 600;
}
#stradella-app .sa-howto strong { color: var(--ac-text); font-weight: 600; }

/* dim footnote — small, muted, set apart for pedants only */
#stradella-app .sa-footnote {
    margin-top: 26px;
    padding: 14px 16px;
    border-top: 1px dashed var(--ac-border);
    font-size: 11px;
    line-height: 1.55;
    color: var(--ac-muted);
}
#stradella-app .sa-footnote .sa-footnote-label {
    display: block;
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--ac-secondary);
    margin-bottom: 4px;
    font-weight: 600;
}
#stradella-app .sa-footnote strong { color: var(--ac-secondary); font-weight: 600; }

/* Tighten on narrow screens */
@media (max-width: 640px) {
    #stradella-app .sa-guide { padding: 18px 16px; margin-top: 24px; }
    #stradella-app .sa-intro { font-size: 13px; }
}