:root {
    --ink: #18311d;
    --ink-soft: rgba(24, 49, 29, 0.78);
    --card-bg: rgba(255, 250, 240, 0.93);
    --line: rgba(24, 49, 29, 0.12);
    --green: #5f8128;
    --green-deep: #284b2d;
    --orange: #e8a03f;
    --shadow: 0 22px 60px rgba(15, 35, 17, 0.18);
    --card-back: #2a5e35;
    --matched: rgba(45, 140, 45, 0.18);
}

* { box-sizing: border-box; }

body {
    margin: 0;
    min-height: 100vh;
    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
    color: var(--ink);
    background:
        radial-gradient(circle at top left, rgba(232, 160, 63, 0.35), transparent 26%),
        radial-gradient(circle at top right, rgba(95, 129, 40, 0.28), transparent 22%),
        linear-gradient(180deg, #16361f 0%, #2f6a3d 23%, #dce6bf 58%, #f5e8ce 100%);
}

a { color: inherit; }

.game-page {
    width: min(1280px, calc(100% - 2rem));
    margin: 0 auto;
    padding: 1.25rem 0 2rem;
}

.game-panel, .card, .overlay-card {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}

.layout {
    display: grid;
    grid-template-columns: minmax(0, 2fr) minmax(280px, 1fr);
    gap: 1.25rem;
    margin-top: 1.25rem;
}

.game-panel {
    border-radius: 1.8rem;
    padding: 1.4rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.title-row {
    display: flex;
    justify-content: space-between;
    align-items: start;
    gap: 1rem;
    flex-wrap: wrap;
}

.title-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    align-items: center;
}

.eyebrow {
    margin: 0;
    color: #75510a;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    font-size: 0.82rem;
    font-weight: 700;
}

h1, h2 { font-family: Georgia, "Times New Roman", serif; }

h1 {
    margin: 0.25rem 0 0;
    font-size: clamp(1.8rem, 4vw, 3rem);
    line-height: 0.98;
}

.lead {
    margin: 0;
    color: var(--ink-soft);
    line-height: 1.6;
    font-size: 1rem;
}

/* HUD */
.hud {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.hud-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    background: rgba(95, 129, 40, 0.12);
    border-radius: 0.75rem;
    padding: 0.5rem 1rem;
    min-width: 5rem;
    flex: 1;
}

.hud-label {
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--ink-soft);
    font-weight: 600;
}

.hud-item strong {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--green-deep);
}

/* Memory board shell */
.memory-shell {
    position: relative;
    border-radius: 1.2rem;
    overflow: hidden;
    background: rgba(255, 252, 244, 0.5);
    border: 1px solid var(--line);
    min-height: 380px;
}

/* Overlay */
.overlay {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(22, 54, 31, 0.55);
    backdrop-filter: blur(6px);
    border-radius: inherit;
    z-index: 20;
    padding: 1rem;
}

.overlay.hidden { display: none; }

.overlay-card {
    border-radius: 1.2rem;
    padding: 2rem;
    max-width: 420px;
    width: 100%;
    text-align: center;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.overlay-brand {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.overlay-brand-icon { width: 32px; height: 32px; border-radius: 8px; }
.overlay-brand-name { font-size: 0.85rem; font-weight: 700; color: var(--ink-soft); }
.overlay-kicker { margin: 0; font-size: 0.88rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--orange); font-weight: 700; }
.overlay-card h2 { margin: 0; font-size: clamp(1.4rem, 3vw, 2rem); }
.overlay-card p { margin: 0; color: var(--ink-soft); line-height: 1.6; font-size: 0.96rem; }

.overlay-actions {
    display: flex;
    gap: 0.75rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 0.5rem;
}

/* Memory grid */
.memory-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.6rem;
    padding: 1.25rem;
}

/* Card flip */
.mem-card {
    position: relative;
    aspect-ratio: 3/4;
    cursor: pointer;
    perspective: 800px;
    user-select: none;
}

.mem-card-inner {
    position: absolute;
    inset: 0;
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    transform-style: preserve-3d;
    border-radius: 0.75rem;
}

.mem-card.flipped .mem-card-inner,
.mem-card.matched .mem-card-inner {
    transform: rotateY(180deg);
}

.mem-card-front,
.mem-card-back {
    position: absolute;
    inset: 0;
    border-radius: 0.75rem;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

/* Back face (card face-down) */
.mem-card-back {
    background: var(--card-back);
    border: 2px solid rgba(255, 255, 255, 0.15);
    flex-direction: column;
    gap: 0.3rem;
}

.mem-card-back .durian-icon {
    font-size: 2rem;
    opacity: 0.55;
}

.mem-card-back .card-back-label {
    font-size: 0.65rem;
    color: rgba(255, 255, 255, 0.5);
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

/* Front face (card face-up) */
.mem-card-front {
    transform: rotateY(180deg);
    background: var(--card-bg);
    border: 2px solid var(--line);
    flex-direction: column;
    padding: 0.5rem 0.4rem;
    text-align: center;
    gap: 0.3rem;
}

.mem-card.matched .mem-card-front {
    background: var(--matched);
    border-color: var(--green);
}

.card-variety-emoji { font-size: 1.8rem; line-height: 1; }
.card-variety-name {
    font-size: 0.72rem;
    font-weight: 700;
    color: var(--green-deep);
    line-height: 1.2;
    padding: 0 0.2rem;
}
.card-variety-sub {
    font-size: 0.62rem;
    color: var(--ink-soft);
    line-height: 1.2;
    padding: 0 0.2rem;
}

.mem-card:hover:not(.flipped):not(.matched) .mem-card-inner {
    transform: rotateY(-15deg);
}

.mem-card:hover:not(.flipped):not(.matched) .mem-card-back {
    background: #3a7a48;
}

/* Buttons */
.primary-button {
    background: #284b2d;
    color: #fffaf0;
    border: none;
    padding: 0.72rem 1.5rem;
    border-radius: 999px;
    font-size: 0.96rem;
    font-weight: 700;
    font-family: inherit;
    cursor: pointer;
    transition: background 0.18s, transform 0.1s;
}
.primary-button:hover { background: #1a3320; transform: translateY(-1px); }

.control-button {
    background: rgba(24, 49, 29, 0.08);
    border: 1px solid var(--line);
    border-radius: 999px;
    color: var(--ink);
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
    font-family: inherit;
    cursor: pointer;
    transition: background 0.15s;
}
.control-button:hover { background: rgba(24, 49, 29, 0.15); }

.canvas-fullscreen-button {
    background: rgba(24, 49, 29, 0.1);
    border: 1px solid var(--line);
    border-radius: 0.5rem;
    width: 2.2rem;
    height: 2.2rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
    transition: background 0.15s;
    fill: var(--ink);
    flex-shrink: 0;
}
.canvas-fullscreen-button:hover { background: rgba(24, 49, 29, 0.2); }

.hidden-action { display: none; }

/* Difficulty buttons */
.diff-row {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.diff-btn {
    border: 2px solid var(--line);
    border-radius: 999px;
    background: transparent;
    font-family: inherit;
    font-size: 0.85rem;
    font-weight: 600;
    padding: 0.4rem 0.9rem;
    cursor: pointer;
    color: var(--ink);
    transition: all 0.15s;
}

.diff-btn.active, .diff-btn:hover {
    background: var(--green);
    border-color: var(--green);
    color: #fff;
}

/* Sidebar */
.sidebar {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.card {
    border-radius: 1.2rem;
    padding: 1.2rem;
}

.card-heading { margin: 0 0 0.75rem; font-size: 1rem; font-weight: 700; color: var(--green-deep); }

.leaderboard-tabs { display: flex; gap: 0.4rem; margin-bottom: 0.75rem; }

.leaderboard-tab {
    padding: 0.35rem 0.75rem;
    border-radius: 999px;
    border: 1px solid var(--line);
    background: transparent;
    font-family: inherit;
    font-size: 0.82rem;
    cursor: pointer;
    color: var(--ink-soft);
    transition: background 0.15s, color 0.15s;
}
.leaderboard-tab.active, .leaderboard-tab:hover { background: var(--green); color: #fff; border-color: var(--green); }

.leaderboard-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
    max-height: 220px;
    overflow-y: auto;
}

.leaderboard-item { display: flex; align-items: center; gap: 0.5rem; font-size: 0.88rem; padding: 0.3rem 0.4rem; border-radius: 0.4rem; }
.leaderboard-item:nth-child(odd) { background: rgba(95, 129, 40, 0.06); }
.lb-rank { min-width: 1.5rem; font-weight: 700; color: var(--ink-soft); font-size: 0.8rem; text-align: right; }
.lb-name { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.lb-score { font-weight: 700; color: var(--green-deep); white-space: nowrap; }
.leaderboard-empty { color: var(--ink-soft); font-size: 0.9rem; padding: 0.5rem 0; text-align: center; }
.refresh-button { margin-top: 0.5rem; font-size: 0.82rem; padding: 0.35rem 0.7rem; }

.form-label { display: block; font-size: 0.88rem; font-weight: 600; margin-bottom: 0.4rem; }
.form-input {
    width: 100%;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--line);
    border-radius: 0.5rem;
    font-family: inherit;
    font-size: 0.95rem;
    background: rgba(255, 252, 244, 0.9);
    color: var(--ink);
    margin-bottom: 0.6rem;
}
.form-input:focus { outline: 2px solid var(--green); outline-offset: 1px; }
#leaderboard-form { display: flex; flex-direction: column; }
.leaderboard-status { margin: 0.5rem 0 0; font-size: 0.85rem; color: var(--ink-soft); min-height: 1.2rem; }

.share-btn {
    padding: 0.5rem 0.6rem;
    border: none;
    border-radius: 0.5rem;
    font-family: inherit;
    font-size: 0.82rem;
    font-weight: 700;
    cursor: pointer;
    transition: opacity 0.15s, transform 0.1s;
    color: #fff;
}
.share-btn:hover { opacity: 0.88; transform: translateY(-1px); }
.share-leaderboard { background: var(--green-deep); }
.share-card .social-share-container { margin: 0; }

.how-list {
    padding: 0;
    margin: 0;
    list-style: none;
    font-size: .88rem;
    color: var(--ink-soft);
    display: flex;
    flex-direction: column;
    gap: .4rem;
}
.how-list li {
    display: flex;
    gap: .5rem;
    line-height: 1.5;
    align-items: flex-start;
}
.how-list li::before {
    content: "›";
    color: var(--green);
    font-weight: 700;
    flex-shrink: 0;
    min-width: 1.2rem;
    text-align: center;
}
.how-list li:has(.icon)::before { display: none; }

/* Fullscreen */
.memory-shell:fullscreen,
.memory-shell:-webkit-full-screen {
    background: #1a3d22;
    border-radius: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}
.memory-shell:fullscreen .memory-grid,
.memory-shell:-webkit-full-screen .memory-grid {
    max-width: 700px;
    width: 100%;
}

@media (max-width: 900px) {
    .memory-grid { grid-template-columns: repeat(4, 1fr); gap: 0.4rem; padding: 0.75rem; }
}
@media (max-width: 720px) {
    .layout { grid-template-columns: 1fr; }
    .game-page { width: calc(100% - 1rem); }
    h1 { font-size: 1.8rem; }
    .memory-grid { grid-template-columns: repeat(4, 1fr); gap: 0.35rem; }
    .leaderboard-tabs { flex-direction: column; }
    .leaderboard-tab { text-align: center; }
    .leaderboard-form-row { flex-direction: column; }
    .leaderboard-input { width: 100%; }
}
@media (max-width: 480px) {
    .memory-grid { grid-template-columns: repeat(4, 1fr); gap: 0.25rem; padding: 0.6rem; }
    .card-variety-name { font-size: 0.6rem; }
}