@import url('https://fonts.googleapis.com/css2?family=Fraunces:ital,opsz,wght@0,9..144,400;0,9..144,500;0,9..144,600;0,9..144,700;0,9..144,900;1,9..144,500;1,9..144,900&family=Hanken+Grotesk:wght@400;500;600;700;800&family=Space+Mono:ital,wght@0,400;0,700;1,400&display=swap');

:root {
    /* ── Surfaces (warm paper) ── */
    --bg:        #e8dcc4;
    --panel:     #f3ead7;
    --panel2:    #e2d4b8;
    --border:    #cdbb98;
    --ink:       #241d15;
    --on-accent: #f6eed9;

    /* ── Text ── */
    --text:      #241d15;
    --text-dim:  #8c7d63;

    /* ── Accents (vintage / amp-room) ── */
    --accent:    #c5421f;  /* vermillion — tube glow */
    --accent2:   #7c4b86;  /* aubergine plum */
    --accent3:   #1f7a6d;  /* petrol teal */

    /* ── System ── */
    --r:        3px;
    --shadow:   3px 3px 0 var(--ink);
    --shadow-sm:2px 2px 0 var(--ink);

    --font-display: 'Fraunces', Georgia, serif;
    --font-body:    'Hanken Grotesk', system-ui, sans-serif;
    --font-mono:    'Space Mono', 'Courier New', monospace;
}

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

html { -webkit-text-size-adjust: 100%; }

body {
    font-family: var(--font-body);
    background-color: var(--bg);
    /* paper grain + faint halftone */
    background-image:
        radial-gradient(var(--border) 0.5px, transparent 0.6px);
    background-size: 9px 9px;
    color: var(--text);
    min-height: 100vh;
    padding: 0 20px 20px;
    display: flex;
    flex-direction: column;
    position: relative;
}

/* film-grain overlay */
body::before {
    content: "";
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 9999;
    opacity: 0.4;
    mix-blend-mode: multiply;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.05'/%3E%3C/svg%3E");
}

.container { max-width: 1320px; margin: 0 auto; width: 100%; flex: 1; }

::selection { background: var(--accent); color: var(--on-accent); }

a { color: var(--accent); }

h1, h2, h3, h4 {
    font-family: var(--font-display);
    font-weight: 800;
    font-optical-sizing: auto;
    line-height: 1.1;
    letter-spacing: -0.01em;
}

/* ── TOP NAV ── */
.topnav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--panel);
    border-bottom: 2px solid var(--ink);
    box-shadow: 0 2px 0 var(--accent);
    padding: 14px 26px;
    margin: 0 -20px 36px;
    position: relative;
}

.topnav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    font-family: var(--font-display);
    font-size: 1.7rem;
    font-weight: 900;
    font-optical-sizing: auto;
    letter-spacing: -0.02em;
    color: var(--ink);
    line-height: 1;
}

.topnav-brand img { display: block; }

.brand-accent { color: var(--accent); font-style: italic; }

.topnav-links { display: flex; gap: 2px; flex-wrap: wrap; }

.topnav-link {
    display: flex;
    align-items: center;
    gap: 6px;
    color: var(--text-dim);
    text-decoration: none;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    padding: 7px 12px;
    border: 1.5px solid transparent;
    border-radius: var(--r);
    transition: color 0.15s, border-color 0.15s, background 0.15s;
}

.topnav-link svg { flex-shrink: 0; }

.topnav-link:hover { color: var(--ink); border-color: var(--border); }

.topnav-link.active {
    color: var(--accent);
    border-color: var(--accent);
    background: color-mix(in srgb, var(--accent) 9%, transparent);
}

/* ── Language toggle (injected by i18n-boot.js) ── */
.lang-toggle {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    margin-left: 8px;
    padding: 6px 10px;
    background: transparent;
    border: 1.5px solid var(--border);
    border-radius: 20px;
    color: var(--text-dim);
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    cursor: pointer;
    transition: color 0.15s, border-color 0.15s;
}

.lang-toggle:hover { border-color: var(--accent); color: var(--ink); }
.lang-toggle .lang-cur { color: var(--accent); }
.lang-toggle .lang-sep { color: var(--border); }
.lang-toggle .lang-alt { color: var(--text-dim); }

@media (max-width: 640px) {
    .lang-toggle { margin-left: 4px; padding: 5px 8px; font-size: 0.62rem; }
}

/* ── FRETBOARD (dark inset display) ── */
.fretboard-section {
    background: #16120c;
    border: 2px solid var(--ink);
    border-radius: var(--r);
    box-shadow: var(--shadow);
    padding: 22px 26px;
}

canvas {
    display: block;
    border-radius: 2px;
    background: #16120c;
    cursor: pointer;
    width: 100%;
}


/* ── CONTROLS BAR (above fretboard) ── */
.controls-bar {
    background: var(--panel);
    border: 2px solid var(--ink);
    border-radius: var(--r);
    box-shadow: var(--shadow);
    padding: 20px 24px;
    margin-bottom: 24px;
    display: flex;
    flex-direction: column;
    gap: 0;
    width: fit-content;
    margin-left: auto;
    margin-right: auto;
}

.selectors {
    display: flex;
    gap: 16px;
    align-items: flex-end;
    flex-wrap: wrap;
    padding-bottom: 16px;
}

.selectors .control-group { min-width: 132px; }

/* ── CHORD INFO BAR ── */
.chord-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding-top: 16px;
    border-top: 1.5px dashed var(--border);
    flex-wrap: wrap;
}

.chord-main {
    display: flex;
    align-items: baseline;
    gap: 0;
    flex-wrap: wrap;
    flex: 1;
    min-width: 0;
}

.chord-name {
    font-family: var(--font-display);
    font-size: 1.4rem;
    font-weight: 800;
    color: var(--ink);
    padding-right: 16px;
    white-space: nowrap;
}

.chord-detail {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--text-dim);
    padding: 0 14px;
    border-left: 1.5px solid var(--border);
    white-space: nowrap;
}

.chord-feeling {
    font-family: var(--font-display);
    font-size: 0.9rem;
    font-style: italic;
    color: var(--accent);
    padding-left: 14px;
    border-left: 1.5px solid var(--border);
    white-space: nowrap;
}

.control-group label {
    display: block;
    font-family: var(--font-mono);
    font-weight: 700;
    margin-bottom: 7px;
    color: var(--ink);
    font-size: 0.68rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

select,
input[type="text"] {
    width: 100%;
    padding: 10px 12px;
    border: 1.5px solid var(--ink);
    border-radius: var(--r);
    background: var(--bg);
    color: var(--ink);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    font-weight: 700;
    cursor: pointer;
    transition: box-shadow 0.15s, border-color 0.15s;
    appearance: none;
    background-image:
        linear-gradient(45deg, transparent 50%, var(--accent) 50%),
        linear-gradient(135deg, var(--accent) 50%, transparent 50%);
    background-position:
        calc(100% - 16px) calc(1em + 1px),
        calc(100% - 11px) calc(1em + 1px);
    background-size: 5px 5px, 5px 5px;
    background-repeat: no-repeat;
    padding-right: 32px;
}

input[type="text"] { background-image: none; cursor: text; }

select:hover,
input[type="text"]:hover { border-color: var(--accent); }

select:focus,
input[type="text"]:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: var(--shadow-sm);
}

button {
    font-family: var(--font-mono);
    padding: 10px 18px;
    border: 1.5px solid var(--ink);
    border-radius: var(--r);
    font-size: 0.76rem;
    font-weight: 700;
    cursor: pointer;
    transition: transform 0.1s, box-shadow 0.1s;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    white-space: nowrap;
    background: var(--panel);
    color: var(--ink);
}

/* Legend */
.legend {
    display: flex;
    gap: 18px;
    flex-wrap: wrap;
    flex-shrink: 0;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--text-dim);
}

.legend-color {
    width: 12px;
    height: 12px;
    border: 1px solid var(--ink);
    flex-shrink: 0;
}

.color-root    { background: var(--accent); }
.color-third   { background: var(--accent2); }
.color-fifth   { background: var(--accent3); }
.color-seventh { background: #d4a843; }


/* ── EXERCISE CARD ── */
.exercise-card {
    background: var(--panel);
    border: 2px solid var(--ink);
    border-left: 8px solid var(--cat-color, var(--accent));
    border-radius: var(--r);
    box-shadow: var(--shadow);
    padding: 22px 26px;
    margin-top: 22px;
    margin-bottom: 36px;
    display: flex;
    flex-direction: column;
    gap: 14px;
}

.exercise-cats {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.exercise-cat-btn {
    background: transparent;
    border: 1.5px solid var(--border);
    border-radius: 20px;
    color: var(--text-dim);
    font-family: var(--font-mono);
    font-size: 0.68rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    padding: 4px 13px;
    cursor: pointer;
    transition: background 0.15s, color 0.15s, border-color 0.15s;
}

.exercise-cat-btn:hover {
    color: var(--cat-color);
    border-color: var(--cat-color);
}

.exercise-cat-btn.active {
    background: var(--cat-color);
    color: var(--on-accent);
    border-color: var(--ink);
}

.exercise-title {
    font-family: var(--font-display);
    font-size: 1.3rem;
    font-weight: 800;
    color: var(--ink);
}

.exercise-desc {
    font-size: 0.95rem;
    color: var(--text);
    line-height: 1.6;
}

.exercise-btn {
    align-self: flex-start;
    background: var(--ink);
    border: 1.5px solid var(--ink);
    border-radius: var(--r);
    box-shadow: var(--shadow-sm);
    color: var(--on-accent);
    font-family: var(--font-mono);
    font-size: 0.74rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 9px 18px;
    cursor: pointer;
    transition: transform 0.1s, box-shadow 0.1s;
}

.exercise-btn:hover { transform: translate(-1px, -1px); box-shadow: 3px 3px 0 var(--cat-color, var(--accent)); }
.exercise-btn:active { transform: translate(2px, 2px); box-shadow: none; }

/* Why-it-matters line */
.exercise-why {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    line-height: 1.55;
    color: var(--text-dim);
    border-left: 2px solid var(--cat-color, var(--accent));
    padding-left: 12px;
}

.exercise-actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    align-items: center;
}

.exercise-actions .exercise-btn { align-self: auto; }

.exercise-example-btn {
    background: transparent;
    border: 1.5px solid var(--cat-color, var(--accent));
    border-radius: var(--r);
    color: var(--cat-color, var(--accent));
    font-family: var(--font-mono);
    font-size: 0.74rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 9px 16px;
    cursor: pointer;
    transition: background 0.15s, color 0.15s;
}
.exercise-example-btn:hover { background: var(--cat-color, var(--accent)); color: var(--on-accent); }

/* Worked example (revealed) */
.exercise-example { display: none; }

.exercise-example.is-open {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
    border-top: 1.5px dashed var(--border);
    padding-top: 16px;
    animation: exFade 0.18s ease;
}

@keyframes exFade { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: none; } }

.exercise-example-head {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--ink);
}

.exercise-example svg {
    display: block;
    border: 2px solid var(--ink);
    border-radius: var(--r);
    box-shadow: var(--shadow-sm);
    max-width: 100%;
    height: auto;
}

.exercise-example-cap {
    font-size: 0.86rem;
    line-height: 1.55;
    color: var(--text);
    max-width: 540px;
}


/* ── FOOTER ── */
.site-footer {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 18px;
    margin: auto -20px 0;
    padding: 16px 24px;
    border-top: 2px solid var(--ink);
}

.footer-brand {
    font-family: var(--font-display);
    font-size: 1.05rem;
    font-weight: 900;
    color: var(--ink);
}

.footer-tagline {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-dim);
}

/* ── RESPONSIVE ── */
@media (max-width: 700px) {
    .selectors .control-group { min-width: 100%; }
    .chord-bar { flex-direction: column; align-items: flex-start; }
    .chord-detail { border-left: none; padding-left: 0; }
    .chord-feeling { border-left: none; padding-left: 0; }
}

@media (max-width: 600px) {
    .topnav {
        flex-direction: column;
        align-items: center;
        gap: 12px;
        padding: 14px 16px;
        margin: 0 -20px 24px;
    }
    .topnav-links { gap: 2px; justify-content: center; }
    .topnav-link { font-size: 0.64rem; padding: 6px 8px; gap: 4px; }

    .fretboard-section {
        overflow-x: auto;
        padding: 14px 12px;
        -webkit-overflow-scrolling: touch;
    }

    .controls-bar {
        width: 100%;
        margin-left: 0;
        margin-right: 0;
    }
}

@media (max-width: 400px) {
    body { padding: 0 12px 12px; }
}

/* ── NEXT STEP CTA ── */
.next-step {
    border-top: 2px solid var(--ink);
    margin: 28px 0 0;
    padding: 22px 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}

.next-step-label {
    font-family: var(--font-mono);
    font-size: 0.68rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-dim);
}

.next-step-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-family: var(--font-display);
    font-size: 1.15rem;
    font-weight: 800;
    color: var(--accent);
    text-decoration: none;
    transition: gap 0.15s;
}
.next-step-link:hover { gap: 14px; }