/**
 * Homepage training surface
 *
 * Chess-specific sections below the hero. Kept separate from home.css so the
 * recommendation, daily desk, library, and training modes remain modular.
 */

.training-room {
    position: relative;
    overflow: hidden;
    background: var(--color-surface-alt);
}

.training-room::before {
    position: absolute;
    inset: 0;
    content: '';
    pointer-events: none;
    opacity: 0.36;
    background-image:
        linear-gradient(45deg, var(--color-border-light) 25%, transparent 25%),
        linear-gradient(-45deg, var(--color-border-light) 25%, transparent 25%);
    background-size: 4rem 4rem;
    -webkit-mask-image: linear-gradient(90deg, transparent, black 55%, transparent);
    mask-image: linear-gradient(90deg, transparent, black 55%, transparent);
}

.training-room .container {
    position: relative;
}

.training-room__head {
    align-items: end;
}

.training-room__date {
    flex: none;
    padding: var(--space-2) var(--space-4);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    color: var(--color-text-secondary);
    background: var(--color-surface);
    font-size: var(--text-sm);
    font-weight: var(--weight-semibold);
}

.training-grid {
    display: grid;
    grid-template-columns: minmax(18rem, 0.82fr) minmax(0, 1.65fr);
    gap: var(--space-5);
    margin-top: var(--space-6);
}

.recommendation {
    --color-heading: var(--color-on-ink);
    display: flex;
    min-height: 100%;
    padding: var(--space-6);
    border: 1px solid var(--color-ink-border);
    border-radius: var(--radius-2xl);
    flex-direction: column;
    align-items: flex-start;
    color: var(--color-on-ink);
    background: var(--gradient-ink);
    box-shadow: var(--shadow-lg);
}

.recommendation__top,
.arena-card__badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
}

.recommendation__icon {
    display: grid;
    width: 2.25rem;
    height: 2.25rem;
    border: 1px solid var(--color-ink-border);
    border-radius: var(--radius-md);
    place-items: center;
    color: var(--color-accent-400);
    background: var(--color-ink-surface-raised);
}

.recommendation__icon svg,
.library-panel__icon svg,
.arena-card__badge svg {
    width: 1.125rem;
    height: 1.125rem;
}

.recommendation__eyebrow {
    color: var(--color-accent-400);
    font-size: var(--text-xs);
    font-weight: var(--weight-bold);
    letter-spacing: var(--tracking-wide);
    text-transform: uppercase;
}

.recommendation__title {
    margin-top: var(--space-5);
    max-width: 14ch;
    color: inherit;
    font-size: var(--text-3xl);
    line-height: var(--leading-tight);
    letter-spacing: var(--tracking-tight);
}

.recommendation__text {
    margin-top: var(--space-4);
    color: var(--color-on-ink-muted);
    font-size: var(--text-base);
    line-height: var(--leading-relaxed);
}

.recommendation__metrics {
    display: grid;
    width: 100%;
    margin: auto 0 var(--space-5);
    padding-top: var(--space-6);
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-3);
}

.recommendation__metrics div {
    min-width: 0;
    padding-top: var(--space-3);
    border-top: 1px solid var(--color-ink-border);
}

.recommendation__metrics dd {
    overflow: hidden;
    color: var(--color-on-ink);
    font-size: var(--text-base);
    font-weight: var(--weight-bold);
    text-overflow: ellipsis;
}

.recommendation__metrics dt {
    margin-top: var(--space-1);
    color: var(--color-on-ink-muted);
    font-size: var(--text-xs);
    line-height: var(--leading-snug);
}

.recommendation__privacy {
    margin-top: var(--space-3);
    color: var(--color-on-ink-muted);
    font-size: var(--text-xs);
    line-height: var(--leading-normal);
}

.daily-lineup {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--space-4);
}

.daily-card {
    display: flex;
    overflow: hidden;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    flex-direction: column;
    background: var(--color-surface);
    box-shadow: var(--shadow-sm);
    transition: transform var(--duration-normal) var(--ease-out), box-shadow var(--duration-normal) var(--ease-out);
}

.daily-card:hover {
    transform: translateY(-0.25rem);
    box-shadow: var(--shadow-lg);
}

.daily-card__board-link {
    position: relative;
    display: block;
    padding: var(--space-3);
    background: var(--color-surface-sunk);
}

.daily-card__board {
    border-width: 2px;
    border-radius: var(--radius-md);
}

.daily-card__number {
    position: absolute;
    top: var(--space-4);
    left: var(--space-4);
    display: grid;
    width: 2rem;
    height: 2rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    place-items: center;
    color: var(--color-text);
    background: var(--color-surface);
    box-shadow: var(--shadow-sm);
    font-size: var(--text-xs);
    font-weight: var(--weight-bold);
}

.daily-card__body {
    position: relative;
    display: flex;
    isolation: isolate;
    flex: 1;
    padding: var(--space-4);
    flex-direction: column;
}

/* A different chess piece peeks into each training card's empty lower-right
   corner. The card clips the artwork, while all real content stays above it. */
.daily-card__body::before {
    position: absolute;
    z-index: 2;
    right: -1.7rem;
    bottom: -1rem;
    width: 7.25rem;
    aspect-ratio: 1;
    content: '';
    background: var(--color-doodle-strong);
    pointer-events: none;
    transform: rotate(-7deg);
    -webkit-mask: url('../img/chess-doodle-sprite.svg?v=2') 40% 0 / 600% 100% no-repeat;
    mask: url('../img/chess-doodle-sprite.svg?v=2') 40% 0 / 600% 100% no-repeat;
}

.daily-card__body > * {
    position: relative;
    z-index: 1;
}

.daily-card:nth-child(2) .daily-card__body::before {
    right: -1.45rem;
    bottom: -0.8rem;
    width: 6.75rem;
    transform: rotate(6deg);
    -webkit-mask-position: 80% 0;
    mask-position: 80% 0;
}

.daily-card:nth-child(3) .daily-card__body::before {
    right: -1.25rem;
    bottom: -0.65rem;
    width: 6.5rem;
    transform: rotate(-4deg);
    -webkit-mask-position: 20% 0;
    mask-position: 20% 0;
}

.daily-card__meta {
    display: flex;
    justify-content: space-between;
    gap: var(--space-2);
    color: var(--color-text-tertiary);
    font-size: var(--text-xs);
    font-weight: var(--weight-semibold);
    text-transform: uppercase;
}

.daily-card h3 {
    margin-top: var(--space-2);
    font-size: var(--text-lg);
    line-height: var(--leading-snug);
}

.daily-card__reason {
    margin-top: var(--space-2);
    color: var(--color-text-secondary);
    font-size: var(--text-sm);
    line-height: var(--leading-normal);
}

.daily-card__body > a,
.arena-card__link {
    display: inline-flex;
    margin-top: var(--space-3);
    align-items: center;
    gap: var(--space-2);
    color: var(--color-primary-600);
    font-size: var(--text-sm);
    font-weight: var(--weight-bold);
}

.daily-card__body > a {
    margin-top: auto;
    padding-top: var(--space-3);
}

.daily-card__body > a svg,
.arena-card__link svg,
.library-list svg {
    width: 1rem;
    height: 1rem;
}

.chess-library {
    background: var(--color-bg);
}

.library-grid {
    display: grid;
    margin-top: var(--space-6);
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--space-5);
}

.library-panel {
    position: relative;
    overflow: hidden;
    padding: var(--space-6);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-2xl);
    background: var(--color-surface);
}

.library-panel::after {
    position: absolute;
    z-index: 2;
    right: calc(-1 * var(--space-8));
    bottom: calc(-1 * var(--space-8));
    width: 9rem;
    aspect-ratio: 1;
    content: '';
    background: var(--color-doodle-strong);
    pointer-events: none;
    transform: rotate(-6deg);
    -webkit-mask: url('../img/chess-doodle-sprite.svg?v=2') 60% 0 / 600% 100% no-repeat;
    mask: url('../img/chess-doodle-sprite.svg?v=2') 60% 0 / 600% 100% no-repeat;
}

.library-panel--openings::after {
    transform: rotate(5deg);
    -webkit-mask-position: 20% 0;
    mask-position: 20% 0;
}

.library-panel > * {
    position: relative;
    z-index: 1;
}

.library-panel__intro {
    display: flex;
    align-items: flex-start;
    gap: var(--space-4);
}

.library-panel__icon {
    display: grid;
    width: 2.75rem;
    height: 2.75rem;
    flex: none;
    border-radius: var(--radius-lg);
    place-items: center;
    color: var(--color-primary-600);
    background: var(--color-primary-50);
}

.library-panel__kicker {
    color: var(--color-primary-600);
    font-size: var(--text-xs);
    font-weight: var(--weight-bold);
    letter-spacing: var(--tracking-wide);
    text-transform: uppercase;
}

.library-panel h3 {
    margin-top: var(--space-1);
    font-size: var(--text-2xl);
    letter-spacing: var(--tracking-tight);
}

.library-panel > p {
    margin-top: var(--space-4);
    max-width: 58ch;
    color: var(--color-text-secondary);
    line-height: var(--leading-relaxed);
}

.library-list,
.opening-list {
    display: grid;
    margin-top: var(--space-5);
    gap: var(--space-2);
}

.library-list a,
.opening-list a {
    display: grid;
    min-height: var(--control-height);
    padding: var(--space-2) var(--space-3);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-md);
    align-items: center;
    color: var(--color-text);
    background: var(--color-surface-alt);
    transition: border-color var(--duration-fast) var(--ease-out), background var(--duration-fast) var(--ease-out);
}

.library-list a {
    grid-template-columns: minmax(0, 1fr) auto auto;
    gap: var(--space-3);
}

.library-list a > span {
    overflow: hidden;
    font-weight: var(--weight-semibold);
    text-overflow: ellipsis;
    white-space: nowrap;
}

.library-list small,
.opening-list__count {
    color: var(--color-text-tertiary);
    font-size: var(--text-xs);
}

.library-list__piece {
    margin-right: var(--space-2);
    color: var(--color-primary-500);
}

.opening-list a {
    grid-template-columns: 3.5rem minmax(0, 1fr) auto;
    gap: var(--space-3);
}

.opening-list__eco {
    color: var(--color-primary-600);
    font-size: var(--text-xs);
    font-weight: var(--weight-bold);
}

.opening-list__name {
    overflow: hidden;
    font-size: var(--text-sm);
    font-weight: var(--weight-semibold);
    text-overflow: ellipsis;
    white-space: nowrap;
}

.opening-list a[data-preferred="true"] {
    border-color: var(--color-accent-500);
    background: color-mix(in srgb, var(--color-accent-500) 8%, var(--color-surface));
}

.opening-list a[data-preferred="true"] .opening-list__count {
    color: var(--color-primary-700);
    font-weight: var(--weight-semibold);
}

.library-list a:hover,
.opening-list a:hover {
    border-color: var(--color-primary-300);
    background: var(--color-primary-50);
}

.library-panel__footer-link {
    display: inline-flex;
    margin-top: var(--space-5);
    min-height: var(--control-height-sm);
    align-items: center;
    color: var(--color-primary-600);
    font-size: var(--text-sm);
    font-weight: var(--weight-bold);
}

.arenas {
    background: var(--color-surface-alt);
}

.arena-grid {
    display: grid;
    margin-top: var(--space-6);
    grid-template-columns: repeat(12, minmax(0, 1fr));
    gap: var(--space-4);
}

.arena-card {
    position: relative;
    display: flex;
    overflow: hidden;
    min-height: 20rem;
    padding: var(--space-5);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-2xl);
    grid-column: span 4;
    flex-direction: column;
    align-items: flex-start;
    background: var(--color-surface);
}

.arena-card::after {
    position: absolute;
    z-index: 2;
    right: calc(-1 * var(--space-6));
    bottom: calc(-1 * var(--space-6));
    width: 7.25rem;
    aspect-ratio: 1;
    content: '';
    background: var(--color-doodle);
    pointer-events: none;
    transform: rotate(7deg);
    -webkit-mask: url('../img/chess-doodle-sprite.svg?v=2') 100% 0 / 600% 100% no-repeat;
    mask: url('../img/chess-doodle-sprite.svg?v=2') 100% 0 / 600% 100% no-repeat;
}

.arena-card > * {
    position: relative;
    z-index: 1;
}

.arena-card--gauntlet::after {
    width: 12rem;
    background: var(--color-doodle-on-ink);
    transform: rotate(-5deg);
    -webkit-mask-position: 0 0;
    mask-position: 0 0;
}

.arena-card--coach::after {
    -webkit-mask-position: 80% 0;
    mask-position: 80% 0;
}

.arena-card--engine::after {
    -webkit-mask-position: 60% 0;
    mask-position: 60% 0;
}

.arena-card--rush::after {
    -webkit-mask-position: 40% 0;
    mask-position: 40% 0;
}

.arena-card--gauntlet {
    --color-heading: var(--color-on-ink);
    display: grid;
    min-height: 25rem;
    padding: var(--space-6);
    border-color: var(--color-ink-border);
    grid-column: span 8;
    grid-template-columns: minmax(0, 1fr) minmax(12rem, 0.72fr);
    align-items: center;
    gap: var(--space-6);
    color: var(--color-on-ink);
    background: var(--gradient-ink);
}

.arena-card__badge {
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius-full);
    color: var(--color-primary-600);
    background: var(--color-primary-50);
    font-size: var(--text-xs);
    font-weight: var(--weight-bold);
    letter-spacing: var(--tracking-wide);
    text-transform: uppercase;
}

.arena-card--gauntlet .arena-card__badge {
    color: var(--color-accent-400);
    background: var(--color-ink-surface-raised);
}

.arena-card h3 {
    margin-top: var(--space-4);
    font-size: var(--text-2xl);
    line-height: var(--leading-tight);
    letter-spacing: var(--tracking-tight);
}

.arena-card > p,
.arena-card__copy > p {
    margin-top: var(--space-3);
    color: var(--color-text-secondary);
    line-height: var(--leading-relaxed);
}

.arena-card--gauntlet h3 {
    max-width: 16ch;
    color: inherit;
    font-size: var(--text-3xl);
}

.arena-card--gauntlet .arena-card__copy > p {
    color: var(--color-on-ink-muted);
}

.arena-card__link {
    margin-top: auto;
    padding-top: var(--space-5);
}

.gauntlet-rungs {
    display: flex;
    margin-block: var(--space-5);
    gap: var(--space-2);
}

.gauntlet-rungs span {
    display: grid;
    width: 2rem;
    height: 2rem;
    border: 1px solid var(--color-ink-border);
    border-radius: var(--radius-sm);
    place-items: center;
    color: var(--color-on-ink-muted);
    background: var(--color-ink-surface-raised);
    font-size: var(--text-xs);
    font-weight: var(--weight-bold);
}

.gauntlet-rungs span:last-child {
    border-color: var(--color-accent-400);
    color: var(--color-on-brass);
    background: var(--gradient-brass);
}

.coach-signal {
    display: grid;
    width: 100%;
    margin-top: var(--space-5);
    gap: var(--space-3);
}

.coach-signal span {
    display: grid;
    grid-template-columns: minmax(4rem, 1fr) 6rem;
    align-items: center;
    gap: var(--space-3);
    color: var(--color-text-secondary);
    font-size: var(--text-xs);
}

.coach-signal i {
    position: relative;
    height: var(--space-2);
    border-radius: var(--radius-full);
    grid-column: 2;
    grid-row: 1;
    background: var(--color-surface-sunk);
}

.coach-signal i::after {
    position: absolute;
    inset: 0 auto 0 0;
    width: 74%;
    border-radius: inherit;
    content: '';
    background: var(--gradient-brand);
}

.coach-signal span:nth-child(2) i::after { width: 52%; }
.coach-signal span:nth-child(3) i::after { width: 86%; }

.engine-line {
    display: grid;
    width: 100%;
    margin-top: var(--space-5);
    padding: var(--space-4);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    grid-template-columns: auto minmax(0, 1fr);
    align-items: center;
    gap: var(--space-2) var(--space-3);
    background: var(--color-surface-sunk);
}

.engine-line__eval {
    padding: var(--space-1) var(--space-2);
    border-radius: var(--radius-sm);
    color: var(--color-on-ink);
    background: var(--color-ink-surface);
    font-size: var(--text-xs);
    font-weight: var(--weight-bold);
}

.engine-line code {
    overflow: hidden;
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    text-overflow: ellipsis;
    white-space: nowrap;
}

.engine-line__depth {
    grid-column: 2;
    color: var(--color-text-tertiary);
    font-size: var(--text-xs);
}

.daily-stamp {
    display: flex;
    width: 100%;
    margin-top: var(--space-5);
    padding: var(--space-4);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    align-items: center;
    gap: var(--space-4);
    background: var(--color-surface-alt);
}

.daily-stamp strong {
    color: var(--color-primary-600);
    font-size: var(--text-4xl);
    line-height: 1;
}

.daily-stamp span {
    color: var(--color-text-secondary);
    font-size: var(--text-xs);
    font-weight: var(--weight-bold);
    letter-spacing: var(--tracking-wide);
}

.session-cta {
    --color-heading: var(--color-on-ink);
    position: relative;
    overflow: hidden;
    padding-block: var(--space-10);
    background: var(--gradient-ink);
}

.session-cta::before,
.session-cta::after {
    position: absolute;
    z-index: 2;
    width: 9rem;
    aspect-ratio: 1;
    content: '';
    background: var(--color-doodle-on-ink);
    pointer-events: none;
    -webkit-mask: url('../img/chess-doodle-sprite.svg?v=2') 20% 0 / 600% 100% no-repeat;
    mask: url('../img/chess-doodle-sprite.svg?v=2') 20% 0 / 600% 100% no-repeat;
}

.session-cta::before {
    top: -3rem;
    left: max(1rem, calc(50% - 43rem));
    transform: rotate(-8deg);
}

.session-cta::after {
    right: max(1rem, calc(50% - 43rem));
    bottom: -3rem;
    transform: rotate(9deg);
    -webkit-mask-position: 80% 0;
    mask-position: 80% 0;
}

.session-cta__inner {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) auto;
    align-items: center;
    gap: var(--space-6);
    color: var(--color-on-ink);
}

.session-cta__piece {
    width: 6rem;
    aspect-ratio: 1;
    overflow: hidden;
    color: transparent;
    background: var(--color-accent-400);
    font-size: 0;
    transform: rotate(-8deg);
    -webkit-mask: url('../img/chess-doodle-sprite.svg?v=2') 0 0 / 600% 100% no-repeat;
    mask: url('../img/chess-doodle-sprite.svg?v=2') 0 0 / 600% 100% no-repeat;
}

.session-cta .section__eyebrow {
    color: var(--color-accent-400);
}

.session-cta h2 {
    max-width: 25ch;
    color: inherit;
    font-size: var(--text-3xl);
    letter-spacing: var(--tracking-tight);
}

.session-cta p {
    margin-top: var(--space-2);
    max-width: 58ch;
    color: var(--color-on-ink-muted);
}

.session-cta__actions {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-3);
}

.session-cta__account {
    color: var(--color-on-ink-muted);
    font-size: var(--text-sm);
    font-weight: var(--weight-semibold);
    text-decoration: underline;
    text-underline-offset: var(--space-1);
}

@media (max-width: 1023px) {
    .training-grid { grid-template-columns: 1fr; }
    .recommendation__title { max-width: 24ch; }
    .daily-card__body::before {
        right: -1.25rem;
        bottom: -0.8rem;
        width: 5.5rem;
    }
    .daily-card:nth-child(2) .daily-card__body::before {
        right: -1.1rem;
        bottom: -0.65rem;
        width: 5.25rem;
    }
    .daily-card:nth-child(3) .daily-card__body::before {
        right: -1rem;
        bottom: -0.55rem;
        width: 5rem;
    }
    .arena-card { grid-column: span 6; }
    .arena-card--gauntlet { grid-column: span 12; }
    .session-cta__inner { grid-template-columns: auto 1fr; }
    .session-cta__actions { grid-column: 2; align-items: flex-start; }
}

@media (max-width: 767px) {
    .training-room__head { align-items: flex-start; }
    .training-grid { grid-template-columns: minmax(0, 1fr); }
    .recommendation { padding: var(--space-5); }
    .recommendation__metrics { margin-top: var(--space-5); }
    .daily-lineup { grid-template-columns: 1fr; }
    .daily-card { display: grid; grid-template-columns: 8.5rem minmax(0, 1fr); }
    .daily-card__body { align-self: center; }
    .daily-card__body::before {
        right: -0.85rem;
        bottom: -0.55rem;
        width: 4.6rem;
        opacity: 0.78;
    }
    .daily-card:nth-child(2) .daily-card__body::before {
        right: -0.7rem;
        bottom: -0.45rem;
        width: 4.35rem;
    }
    .daily-card:nth-child(3) .daily-card__body::before {
        right: -0.65rem;
        bottom: -0.4rem;
        width: 4.2rem;
    }
    .library-grid { grid-template-columns: 1fr; }
    .library-panel { padding: var(--space-5); }
    .arena-card,
    .arena-card--gauntlet { grid-column: span 12; }
    .arena-card--gauntlet { grid-template-columns: minmax(0, 1fr) 12rem; }
    .session-cta__inner { grid-template-columns: 1fr; text-align: center; }
    .session-cta__piece { display: none; }
    .session-cta::before { left: -3rem; }
    .session-cta::after { right: -3rem; }
    .session-cta__actions { grid-column: 1; align-items: center; }
}

@media (max-width: 560px) {
    .recommendation__title { font-size: var(--text-2xl); }
    .recommendation__metrics { grid-template-columns: 1fr; }
    .recommendation__metrics div { display: flex; justify-content: space-between; gap: var(--space-3); }
    .daily-card { grid-template-columns: 7.25rem minmax(0, 1fr); }
    .daily-card__meta { flex-direction: column; }
    .library-panel h3 { font-size: var(--text-xl); }
    .arena-card--gauntlet { display: flex; }
    .opening-list a { grid-template-columns: 2.75rem minmax(0, 1fr); }
    .opening-list__count { display: none; }
}

@media (prefers-reduced-motion: reduce) {
    .daily-card { transition: none; }
    .daily-card:hover { transform: none; }
}