:root {
    --bg: #0c1117;
    --bg-soft: #111923;
    --panel: #151f2b;
    --panel-light: #1a2735;
    --border: #29394a;

    --text: #f4f7fa;
    --muted: #9aabbc;

    --blue: #3588ff;
    --blue-light: #6daaff;
    --blue-dark: #1f63c7;

    --gold: #e7b84d;

    --shadow: 0 18px 45px rgba(0, 0, 0, 0.26);

    --radius: 18px;
}


* {
    box-sizing: border-box;
}


html {
    scroll-behavior: smooth;
}


body {
    margin: 0;

    font-family:
        Inter,
        ui-sans-serif,
        system-ui,
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        sans-serif;

    background:
        radial-gradient(
            circle at top right,
            rgba(53, 136, 255, 0.08),
            transparent 34rem
        ),
        var(--bg);

    color: var(--text);

    min-height: 100vh;
}


a {
    color: inherit;
    text-decoration: none;
}


button,
input,
select {
    font: inherit;
}


/* HEADER */

.site-header {
    position: sticky;
    top: 0;
    z-index: 100;

    border-bottom: 1px solid rgba(255, 255, 255, 0.06);

    background: rgba(12, 17, 23, 0.92);

    backdrop-filter: blur(14px);
}


.header-inner {
    width: min(1180px, calc(100% - 36px));
    min-height: 74px;

    margin: 0 auto;

    display: flex;
    align-items: center;
    justify-content: space-between;

    gap: 24px;
}


.brand {
    display: flex;
    align-items: center;

    gap: 12px;
}


.brand-icon {
    width: 46px;
    height: 46px;

    display: grid;
    place-items: center;

    background: linear-gradient(
        135deg,
        var(--blue),
        var(--blue-dark)
    );

    border-radius: 14px;

    font-size: 24px;

    box-shadow: 0 8px 24px rgba(53, 136, 255, 0.25);
}


.brand-text {
    display: flex;
    flex-direction: column;

    line-height: 1.05;
}


.brand-text strong {
    font-size: 18px;
}


.brand-text span {
    color: var(--blue-light);

    font-weight: 700;
}


.main-nav {
    display: flex;
    align-items: center;

    gap: 8px;
}


.main-nav a {
    padding: 10px 14px;

    color: #c8d4df;

    border-radius: 10px;

    transition:
        background 0.18s ease,
        color 0.18s ease;
}


.main-nav a:hover {
    background: rgba(255, 255, 255, 0.06);

    color: white;
}


.disabled-link {
    opacity: 0.55;
}


/* BUTTONS */

.button {
    min-height: 46px;

    padding: 0 20px;

    display: inline-flex;
    align-items: center;
    justify-content: center;

    border: 1px solid transparent;
    border-radius: 12px;

    cursor: pointer;

    font-weight: 750;

    transition:
        transform 0.18s ease,
        box-shadow 0.18s ease,
        background 0.18s ease;
}


.button:hover {
    transform: translateY(-1px);
}


.button.primary {
    color: white;

    background: linear-gradient(
        135deg,
        var(--blue),
        var(--blue-dark)
    );

    box-shadow: 0 10px 26px rgba(53, 136, 255, 0.22);
}


.button.secondary {
    color: #d9e3ec;

    background: #182331;

    border-color: var(--border);
}


.disabled-button {
    opacity: 0.55;

    cursor: default;
}


.disabled-button:hover {
    transform: none;
}


/* HERO */

.hero {
    min-height: 570px;

    display: flex;
    align-items: center;

    border-bottom: 1px solid rgba(255, 255, 255, 0.05);

    background:
        linear-gradient(
            90deg,
            rgba(12, 17, 23, 0.99) 10%,
            rgba(12, 17, 23, 0.88) 60%,
            rgba(12, 17, 23, 0.7)
        ),
        radial-gradient(
            circle at 80% 50%,
            rgba(53, 136, 255, 0.22),
            transparent 27rem
        );
}


.hero-content {
    width: min(1180px, calc(100% - 36px));

    margin: 0 auto;

    padding: 80px 0;

    max-width: 1180px;
}


.hero-kicker,
.section-kicker,
.detail-label {
    color: var(--blue-light);

    font-size: 12px;

    font-weight: 850;

    letter-spacing: 0.16em;

    text-transform: uppercase;
}


.hero h1 {
    max-width: 800px;

    margin: 16px 0 20px;

    font-size: clamp(42px, 6vw, 76px);

    line-height: 0.99;

    letter-spacing: -0.045em;
}


.hero h1 span {
    color: var(--blue-light);
}


.hero-description {
    max-width: 720px;

    margin: 0;

    color: #acbac7;

    font-size: 19px;

    line-height: 1.7;
}


.hero-actions {
    margin-top: 32px;

    display: flex;

    gap: 12px;

    flex-wrap: wrap;
}


/* STATS */

.stats-section {
    width: min(1180px, calc(100% - 36px));

    margin: -42px auto 0;

    position: relative;
    z-index: 5;
}


.stats-grid {
    display: grid;

    grid-template-columns: repeat(3, 1fr);

    gap: 16px;
}


.stat-card {
    padding: 25px;

    text-align: center;

    background: rgba(21, 31, 43, 0.98);

    border: 1px solid var(--border);

    border-radius: var(--radius);

    box-shadow: var(--shadow);
}


.stat-number {
    color: var(--blue-light);

    font-size: 34px;

    font-weight: 850;
}


.stat-label {
    margin-top: 4px;

    color: var(--muted);

    font-size: 14px;
}


/* GENERAL CONTENT */

.content-section,
.feature-section,
.catalog-section,
.detail-section {
    width: min(1180px, calc(100% - 36px));

    margin: 0 auto;

    padding: 82px 0;
}


.section-heading {
    margin-bottom: 28px;

    display: flex;
    align-items: end;
    justify-content: space-between;

    gap: 30px;
}


.section-heading h2 {
    margin: 8px 0 0;

    font-size: clamp(28px, 4vw, 42px);

    letter-spacing: -0.03em;
}


.section-heading > p {
    max-width: 480px;

    margin: 0;

    color: var(--muted);

    line-height: 1.6;
}


/* CATEGORY CARDS */

.category-grid {
    display: grid;

    grid-template-columns: repeat(2, 1fr);

    gap: 14px;
}


.category-card {
    padding: 22px;

    display: grid;

    grid-template-columns: auto 1fr auto;

    align-items: center;

    gap: 18px;

    background: var(--panel);

    border: 1px solid var(--border);

    border-radius: 16px;

    transition:
        transform 0.18s ease,
        border-color 0.18s ease,
        background 0.18s ease;
}


.category-card:hover {
    transform: translateY(-2px);

    background: var(--panel-light);

    border-color: rgba(109, 170, 255, 0.6);
}


.category-icon {
    width: 48px;
    height: 48px;

    display: grid;
    place-items: center;

    color: white;

    background: rgba(53, 136, 255, 0.14);

    border: 1px solid rgba(109, 170, 255, 0.25);

    border-radius: 13px;

    font-size: 24px;
}


.category-card h3 {
    margin: 0 0 5px;

    font-size: 18px;
}


.category-card p {
    margin: 0;

    color: var(--muted);

    font-size: 14px;
}


.category-arrow {
    color: var(--blue-light);

    font-size: 24px;
}


/* FEATURES */

.feature-section {
    padding-top: 20px;
}


.feature-grid {
    display: grid;

    grid-template-columns: repeat(4, 1fr);

    gap: 16px;
}


.feature-card {
    padding: 25px;

    background: linear-gradient(
        180deg,
        var(--panel-light),
        var(--panel)
    );

    border: 1px solid var(--border);

    border-radius: var(--radius);
}


.feature-icon {
    width: 46px;
    height: 46px;

    display: grid;
    place-items: center;

    margin-bottom: 18px;

    color: var(--blue-light);

    background: rgba(53, 136, 255, 0.1);

    border-radius: 12px;

    font-size: 21px;

    font-weight: 850;
}


.feature-card h3 {
    margin: 0 0 10px;
}


.feature-card p {
    min-height: 90px;

    margin: 0 0 18px;

    color: var(--muted);

    line-height: 1.6;
}


.coming-soon {
    display: inline-block;

    padding: 6px 10px;

    color: #c6d9ee;

    background: rgba(53, 136, 255, 0.1);

    border: 1px solid rgba(109, 170, 255, 0.18);

    border-radius: 999px;

    font-size: 12px;

    font-weight: 750;
}


/* PAGE HERO */

.page-hero {
    background:
        radial-gradient(
            circle at 78% 25%,
            rgba(53, 136, 255, 0.15),
            transparent 28rem
        ),
        var(--bg-soft);

    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}


.page-hero.compact {
    padding: 54px 0;
}


.page-hero-inner {
    width: min(1180px, calc(100% - 36px));

    margin: 0 auto;
}


.page-hero h1 {
    margin: 10px 0 10px;

    font-size: clamp(38px, 5vw, 56px);

    letter-spacing: -0.04em;
}


.page-hero p {
    max-width: 720px;

    color: var(--muted);

    line-height: 1.6;
}


/* FILTERS */

.catalog-section {
    padding-top: 42px;
}


.filter-panel {
    padding: 18px;

    display: grid;

    grid-template-columns: minmax(220px, 2fr) 1fr 1.3fr auto;

    gap: 14px;

    align-items: end;

    background: var(--panel);

    border: 1px solid var(--border);

    border-radius: var(--radius);
}


.filter-field {
    display: flex;

    flex-direction: column;

    gap: 7px;
}


.filter-field label {
    color: #bdc9d4;

    font-size: 13px;

    font-weight: 750;
}


.filter-field input,
.filter-field select {
    width: 100%;
    min-height: 46px;

    padding: 0 13px;

    color: var(--text);

    background: #0e1620;

    border: 1px solid #334354;

    border-radius: 10px;

    outline: none;
}


.filter-field input:focus,
.filter-field select:focus {
    border-color: var(--blue);
}


.filter-field select option {
    background: #101820;
}


.filter-actions {
    display: flex;

    gap: 8px;
}


.results-header {
    margin: 28px 2px 16px;

    color: var(--muted);
}


.results-header strong {
    color: white;
}


/* SCALE CARDS */

.scale-grid {
    display: grid;

    grid-template-columns: repeat(3, 1fr);

    gap: 16px;
}


.scale-card {
    padding: 22px;

    background: var(--panel);

    border: 1px solid var(--border);

    border-radius: var(--radius);

    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.12);

    transition:
        transform 0.18s ease,
        border-color 0.18s ease,
        background 0.18s ease;
}


.scale-card:hover {
    transform: translateY(-3px);

    background: var(--panel-light);

    border-color: rgba(109, 170, 255, 0.55);
}


.scale-card-top {
    display: flex;

    align-items: center;
    justify-content: space-between;

    gap: 10px;
}


.key-badge,
.category-badge {
    display: inline-flex;

    align-items: center;

    min-height: 28px;

    padding: 0 9px;

    border-radius: 999px;

    font-size: 11px;

    font-weight: 800;
}


.key-badge {
    color: white;

    background: var(--blue);
}


.category-badge {
    color: #b8c8d8;

    background: rgba(255, 255, 255, 0.05);

    border: 1px solid rgba(255, 255, 255, 0.07);
}


.scale-card h2 {
    margin: 20px 0 5px;

    font-size: 22px;
}


.alternate-name {
    min-height: 21px;

    color: var(--muted);

    font-size: 13px;
}


.note-row {
    min-height: 76px;

    margin-top: 18px;

    display: flex;

    align-content: flex-start;

    gap: 6px;

    flex-wrap: wrap;
}


.note-pill {
    min-width: 30px;

    padding: 6px 8px;

    text-align: center;

    color: #d9eaff;

    background: rgba(53, 136, 255, 0.1);

    border: 1px solid rgba(109, 170, 255, 0.17);

    border-radius: 8px;

    font-size: 12px;

    font-weight: 750;
}


.scale-card-footer {
    margin-top: 18px;
    padding-top: 14px;

    display: flex;

    align-items: center;
    justify-content: space-between;

    gap: 15px;

    color: var(--muted);

    border-top: 1px solid rgba(255, 255, 255, 0.06);

    font-size: 12px;
}


.open-scale {
    color: var(--blue-light);

    font-weight: 750;

    white-space: nowrap;
}


/* EMPTY STATE */

.empty-state {
    padding: 70px 20px;

    text-align: center;

    background: var(--panel);

    border: 1px solid var(--border);

    border-radius: var(--radius);
}


.empty-icon {
    font-size: 42px;
}


.empty-state h2 {
    margin-bottom: 8px;
}


.empty-state p {
    margin-bottom: 25px;

    color: var(--muted);
}


/* DETAIL */

.back-link {
    display: inline-block;

    margin-bottom: 24px;

    color: var(--blue-light);

    font-weight: 700;
}


.detail-title-row {
    display: flex;

    align-items: end;
    justify-content: space-between;

    gap: 25px;
}


.detail-title-row h1 {
    margin-bottom: 4px;
}


.alternate-detail {
    margin: 0 !important;
}


.favorite-button {
    min-height: 44px;

    padding: 0 16px;

    color: #dce8f4;

    background: #172331;

    border: 1px solid var(--border);

    border-radius: 12px;
}


.disabled-favorite {
    opacity: 0.6;
}


.detail-section {
    padding-top: 42px;
}


.detail-grid {
    display: grid;

    grid-template-columns: 2fr 1fr;

    gap: 16px;
}


.detail-card {
    padding: 25px;

    background: var(--panel);

    border: 1px solid var(--border);

    border-radius: var(--radius);
}


.detail-card.prominent {
    background:
        radial-gradient(
            circle at 90% 15%,
            rgba(53, 136, 255, 0.11),
            transparent 18rem
        ),
        var(--panel);
}


.large-note-row {
    margin-top: 18px;

    display: flex;

    gap: 8px;

    flex-wrap: wrap;
}


.large-note-pill {
    min-width: 48px;
    height: 48px;

    display: grid;
    place-items: center;

    color: #dcecff;

    background: rgba(53, 136, 255, 0.1);

    border: 1px solid rgba(109, 170, 255, 0.23);

    border-radius: 50%;

    font-size: 15px;

    font-weight: 850;
}


.root-note {
    color: white;

    background: var(--blue);

    border-color: var(--blue-light);

    box-shadow: 0 0 0 3px rgba(53, 136, 255, 0.15);
}


.formula-display {
    margin-top: 18px;

    color: #dce8f2;

    font-size: 19px;

    font-weight: 700;

    line-height: 1.7;
}


.description-card {
    margin-top: 16px;
}


.description-card p {
    margin-bottom: 0;

    color: #b4c2ce;

    font-size: 17px;

    line-height: 1.75;
}


.future-card {
    margin-top: 16px;
}


.future-heading {
    display: flex;

    justify-content: space-between;

    gap: 20px;
}


.future-heading h2,
.future-card h2 {
    margin: 7px 0 10px;
}


.fretboard-placeholder {
    position: relative;

    min-height: 245px;

    margin-top: 26px;

    overflow: hidden;

    background: #0b1118;

    border: 1px solid #283645;

    border-radius: 14px;
}


.fretboard-lines {
    position: absolute;

    inset: 26px;

    display: flex;
    flex-direction: column;
    justify-content: space-around;
}


.fretboard-lines span {
    height: 2px;

    background: rgba(183, 196, 208, 0.3);
}


.placeholder-message {
    position: absolute;

    inset: 0;

    display: grid;
    place-items: center;

    color: var(--muted);

    text-align: center;

    font-weight: 700;
}


.two-column-detail {
    display: grid;

    grid-template-columns: 1fr 1fr;

    gap: 16px;
}


.future-card p {
    color: var(--muted);

    line-height: 1.6;
}


/* FOOTER */

.site-footer {
    margin-top: 40px;

    background: #080d12;

    border-top: 1px solid rgba(255, 255, 255, 0.06);
}


.footer-inner {
    width: min(1180px, calc(100% - 36px));

    margin: 0 auto;

    padding: 35px 0;

    display: flex;

    align-items: center;
    justify-content: space-between;

    gap: 25px;
}


.footer-inner p {
    margin: 5px 0 0;

    color: var(--muted);

    font-size: 13px;
}


.footer-note {
    color: var(--muted);

    font-size: 13px;
}


/* MOBILE */

@media (max-width: 960px) {

    .feature-grid {
        grid-template-columns: repeat(2, 1fr);
    }


    .scale-grid {
        grid-template-columns: repeat(2, 1fr);
    }


    .filter-panel {
        grid-template-columns: 1fr 1fr;
    }


    .search-field {
        grid-column: 1 / -1;
    }


    .filter-actions {
        align-self: end;
    }

}


@media (max-width: 700px) {

    .header-inner {
        min-height: 68px;
    }


    .brand-text {
        display: none;
    }


    .main-nav {
        gap: 2px;
    }


    .main-nav a {
        padding: 9px 10px;

        font-size: 14px;
    }


    .hero {
        min-height: auto;
    }


    .hero-content {
        padding: 65px 0 88px;
    }


    .hero-description {
        font-size: 17px;
    }


    .stats-grid {
        grid-template-columns: 1fr;
    }


    .category-grid,
    .feature-grid,
    .scale-grid,
    .detail-grid,
    .two-column-detail {
        grid-template-columns: 1fr;
    }


    .section-heading {
        align-items: start;
        flex-direction: column;
    }


    .filter-panel {
        grid-template-columns: 1fr;
    }


    .search-field {
        grid-column: auto;
    }


    .filter-actions {
        width: 100%;
    }


    .filter-actions .button {
        flex: 1;
    }


    .detail-title-row {
        align-items: start;
        flex-direction: column;
    }


    .favorite-button {
        width: 100%;
    }


    .scale-card-footer {
        align-items: start;
        flex-direction: column;
    }


    .future-heading {
        align-items: start;
        flex-direction: column;
    }


    .footer-inner {
        align-items: start;
        flex-direction: column;
    }

}