* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    user-select: none;
    -webkit-user-select: none;
}

body {
    overflow: hidden;
    background: #1a1a2e;
    font-family: "Arial", sans-serif;
    color: #e4e4e7;
    min-height: 100vh;
    min-height: 100dvh;
    touch-action: none;
}

#gameCanvas {
    display: block;
    position: fixed;
    cursor: crosshair;
    border-radius: 4px;
    box-shadow: 0 0 24px rgba(0, 0, 0, 0.45);
}

/* ── HUD ─────────────────────────────────── */
#hud {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 44px;
    background: rgba(0, 0, 0, 0.78);
    display: none;
    align-items: center;
    justify-content: space-between;
    padding: env(safe-area-inset-top) max(16px, env(safe-area-inset-right)) 0 max(16px, env(safe-area-inset-left));
    z-index: 20;
    backdrop-filter: blur(6px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

#hud-left,
#hud-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

.hud-item {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 14px;
    font-weight: 600;
}

.hud-icon {
    font-size: 16px;
}

.hud-title {
    font-size: 15px;
    font-weight: 700;
    letter-spacing: 0.04em;
}

.hud-back,
.hud-btn {
    text-decoration: none;
    color: rgba(255, 255, 255, 0.7);
    font-size: 12px;
    padding: 4px 10px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 4px;
    background: transparent;
    cursor: pointer;
    transition:
        background 0.2s,
        color 0.2s;
}

.hud-back:hover,
.hud-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
}

/* ── Shop bar ────────────────────────────── */
#shop-bar {
    position: fixed;
    bottom: 16px;
    left: 50%;
    transform: translateX(-50%);
    display: none;
    gap: 8px;
    align-items: center;
    background: rgba(0, 0, 0, 0.82);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 12px;
    padding: 10px 14px;
    z-index: 25;
    backdrop-filter: blur(6px);
    max-width: calc(100vw - 24px);
    flex-wrap: wrap;
    justify-content: center;
}

#tower-info {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    min-width: min(220px, 70vw);
    max-width: 280px;
    padding: 6px 10px;
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

#tower-info-emoji {
    font-size: 22px;
    line-height: 1;
}

.tower-info-text {
    display: flex;
    flex-direction: column;
    gap: 2px;
    text-align: left;
}

#tower-info-name {
    font-size: 12px;
    font-weight: 700;
}

#tower-info-desc {
    font-size: 11px;
    line-height: 1.35;
    color: rgba(255, 255, 255, 0.65);
}

.tower-btn {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
    min-width: 72px;
    padding: 8px 10px;
    border-radius: 8px;
    border: 2px solid transparent;
    background: rgba(255, 255, 255, 0.08);
    color: #e4e4e7;
    cursor: pointer;
    transition:
        border-color 0.15s,
        background 0.15s;
}

.tower-btn:hover {
    background: rgba(255, 255, 255, 0.14);
}

.tower-btn.active {
    border-color: #f1c40f;
    background: rgba(241, 196, 15, 0.15);
}

.tower-btn.unaffordable {
    opacity: 0.45;
}

.tower-tip {
    position: absolute;
    bottom: calc(100% + 10px);
    left: 50%;
    transform: translateX(-50%);
    width: max-content;
    max-width: 220px;
    padding: 8px 10px;
    border-radius: 8px;
    background: rgba(10, 12, 28, 0.96);
    border: 1px solid rgba(241, 196, 15, 0.35);
    color: #e4e4e7;
    font-size: 11px;
    font-weight: 500;
    line-height: 1.35;
    text-align: left;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition:
        opacity 0.15s,
        visibility 0.15s;
    z-index: 40;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.45);
}

.tower-tip::after {
    content: "";
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    border: 6px solid transparent;
    border-top-color: rgba(10, 12, 28, 0.96);
}

.tower-btn:hover .tower-tip,
.tower-btn:focus-visible .tower-tip {
    opacity: 1;
    visibility: visible;
}

.tower-emoji {
    font-size: 22px;
    line-height: 1;
}

.tower-name {
    font-size: 11px;
    font-weight: 700;
}

.tower-cost {
    font-size: 10px;
    color: rgba(255, 255, 255, 0.65);
}

#btn-start-wave {
    background: #27ae60;
    color: #fff;
    border: none;
    border-radius: 8px;
    padding: 12px 16px;
    font-weight: 700;
    font-size: 13px;
    cursor: pointer;
    min-width: 130px;
}

#btn-start-wave:hover:not(:disabled) {
    background: #219150;
}

#btn-start-wave:disabled {
    background: #555;
    cursor: not-allowed;
}

#wave-preview {
    font-size: 11px;
    color: rgba(255, 255, 255, 0.55);
    max-width: 140px;
    line-height: 1.3;
}

/* ── Sell panel ──────────────────────────── */
#sell-panel {
    position: fixed;
    top: 60px;
    right: 16px;
    background: rgba(0, 0, 0, 0.85);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 10px;
    padding: 14px 16px;
    z-index: 25;
    display: none;
    min-width: 180px;
}

#sell-name {
    font-weight: 700;
    margin-bottom: 4px;
}

#sell-desc {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.6);
    margin-bottom: 6px;
    line-height: 1.4;
}

#sell-stats {
    font-size: 11px;
    color: #f1c40f;
    margin-bottom: 4px;
    font-weight: 600;
}

#sell-next {
    font-size: 11px;
    color: rgba(255, 255, 255, 0.55);
    margin-bottom: 10px;
    line-height: 1.35;
}

#btn-upgrade {
    width: 100%;
    background: #27ae60;
    color: #fff;
    border: none;
    border-radius: 6px;
    padding: 8px;
    font-weight: 700;
    cursor: pointer;
    margin-bottom: 8px;
}

#btn-upgrade:hover:not(:disabled) {
    background: #219a52;
}

#btn-upgrade:disabled {
    opacity: 0.45;
    cursor: not-allowed;
}

#btn-sell {
    width: 100%;
    background: #e67e22;
    color: #fff;
    border: none;
    border-radius: 6px;
    padding: 8px;
    font-weight: 700;
    cursor: pointer;
}

#btn-sell:hover {
    background: #d35400;
}

.btn-deselect-tower {
    width: 100%;
    background: rgba(255, 255, 255, 0.1);
    color: #e4e4e7;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 6px;
    padding: 7px;
    font-weight: 600;
    cursor: pointer;
    margin-bottom: 8px;
}

.btn-deselect-tower:hover {
    background: rgba(255, 255, 255, 0.16);
}

/* ── Mobile bar ──────────────────────────── */
#mobile-bar {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: calc(56px + env(safe-area-inset-bottom));
    background: rgba(0, 0, 0, 0.9);
    display: none;
    align-items: center;
    justify-content: space-around;
    z-index: 30;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding: 0 max(4px, env(safe-area-inset-right)) env(safe-area-inset-bottom) max(4px, env(safe-area-inset-left));
}

.mobile-tower-btn {
    flex: 1;
    background: transparent;
    border: none;
    color: #e4e4e7;
    font-size: 20px;
    padding: 8px 4px;
    cursor: pointer;
    border-radius: 6px;
}

.mobile-tower-btn.active {
    background: rgba(241, 196, 15, 0.2);
}

/* ── Overlays ────────────────────────────── */
.screen-overlay {
    position: fixed;
    inset: 0;
    background: rgba(10, 12, 28, 0.92);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 50;
    gap: 12px;
    text-align: center;
    padding: 24px;
    padding:
        max(24px, env(safe-area-inset-top))
        max(16px, env(safe-area-inset-right))
        max(24px, env(safe-area-inset-bottom))
        max(16px, env(safe-area-inset-left));
    overflow-y: auto;
}

.screen-title {
    font-size: 42px;
    font-weight: 800;
    letter-spacing: 0.02em;
}

.screen-subtitle {
    font-size: 16px;
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 12px;
    line-height: 1.5;
}

.menu-btn {
    background: #27ae60;
    color: #fff;
    border: none;
    border-radius: 10px;
    padding: 14px 36px;
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
    min-width: 200px;
    text-decoration: none;
    display: inline-block;
    transition: background 0.2s;
    min-height: 44px;
}

.menu-btn:hover {
    background: #219150;
}

.menu-btn.secondary {
    background: rgba(255, 255, 255, 0.1);
}

.menu-btn.secondary:hover {
    background: rgba(255, 255, 255, 0.18);
}

.difficulty-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
    width: min(360px, 90vw);
    margin: 8px 0 16px;
    text-align: left;
}

.difficulty-group-label {
    font-size: 13px;
    font-weight: 700;
    color: rgba(255, 255, 255, 0.55);
    margin-bottom: 4px;
}

.difficulty-option {
    display: block;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 8px;
    padding: 12px 14px;
    cursor: pointer;
}

.difficulty-option:has(input:checked) {
    border-color: #f1c40f;
    background: rgba(241, 196, 15, 0.12);
}

.difficulty-row {
    display: flex;
    align-items: center;
    gap: 10px;
}

.difficulty-name {
    font-weight: 700;
}

.difficulty-desc {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.55);
    margin-top: 4px;
    margin-left: 26px;
}

#high-wave {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.5);
    margin-top: 4px;
}

.feathers-gained {
    color: #f1c40f !important;
    font-weight: 700;
    font-size: 15px !important;
}

.meta-feather-balance {
    font-size: 18px;
    margin-bottom: 8px;
}

.meta-upgrade-list {
    width: min(440px, 92vw);
    max-height: min(48vh, 420px);
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin: 8px 0 16px;
    text-align: left;
}

.meta-upgrade {
    display: flex;
    align-items: center;
    gap: 12px;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 10px;
    padding: 10px 12px;
}

.meta-upgrade.maxed {
    opacity: 0.7;
}

.meta-upgrade-icon {
    font-size: 24px;
    width: 32px;
    text-align: center;
}

.meta-upgrade-info {
    flex: 1;
    min-width: 0;
}

.meta-upgrade-name {
    font-weight: 700;
    font-size: 14px;
}

.meta-lvl {
    font-weight: 600;
    font-size: 11px;
    color: rgba(255, 255, 255, 0.45);
    margin-left: 6px;
}

.meta-upgrade-desc {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.55);
    margin-top: 2px;
}

.meta-buy-btn {
    background: #f1c40f;
    color: #1a1a2e;
    border: none;
    border-radius: 8px;
    padding: 8px 12px;
    font-weight: 800;
    font-size: 13px;
    cursor: pointer;
    white-space: nowrap;
    min-width: 72px;
}

.meta-buy-btn:hover:not(:disabled) {
    background: #f39c12;
}

.meta-buy-btn:disabled {
    background: #555;
    color: #aaa;
    cursor: not-allowed;
}

/* ── Tutorial ────────────────────────────── */
#tutorial-panel {
    position: fixed;
    top: 60px;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(0, 0, 0, 0.88);
    border: 1px solid rgba(241, 196, 15, 0.4);
    border-radius: 10px;
    padding: 14px 18px;
    z-index: 40;
    display: none;
    max-width: min(420px, 90vw);
    text-align: center;
}

.tutorial-step-label {
    font-size: 11px;
    color: #f1c40f;
    font-weight: 700;
    margin-bottom: 6px;
}

.tutorial-message {
    font-size: 14px;
    line-height: 1.4;
    margin-bottom: 10px;
}

.tutorial-skip-btn {
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.25);
    color: rgba(255, 255, 255, 0.7);
    border-radius: 6px;
    padding: 4px 12px;
    font-size: 12px;
    cursor: pointer;
}

/* ── Game over ───────────────────────────── */
#game-over {
    display: none;
}

#game-over h1 {
    font-size: 36px;
    margin-bottom: 8px;
}

#game-over p {
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 16px;
}

@media (max-width: 768px) {
    #hud {
        height: calc(44px + env(safe-area-inset-top));
        padding-left: max(8px, env(safe-area-inset-left));
        padding-right: max(8px, env(safe-area-inset-right));
    }

    #hud-left,
    #hud-right {
        gap: 8px;
    }

    .hud-title {
        display: none;
    }

    .hud-back {
        display: none;
    }

    .hud-btn {
        min-width: 44px;
        min-height: 36px;
    }

    #shop-bar {
        bottom: calc(64px + env(safe-area-inset-bottom));
        padding: 8px;
        gap: 4px;
        width: calc(100vw - 16px);
        max-height: min(42dvh, 250px);
        overflow-y: auto;
    }

    #tower-info {
        flex: 1 1 100%;
        max-width: none;
        order: -1;
    }

    .tower-btn {
        min-width: 58px;
        min-height: 52px;
        padding: 6px;
    }

    .tower-tip {
        display: none;
    }

    .tower-name {
        font-size: 9px;
    }

    #wave-preview {
        display: none;
    }

    .screen-title {
        font-size: clamp(1.9rem, 10vw, 2.6rem);
    }

    #sell-panel {
        top: calc(52px + env(safe-area-inset-top));
        right: max(8px, env(safe-area-inset-right));
        left: max(8px, env(safe-area-inset-left));
        min-width: 0;
        max-height: calc(100dvh - 130px - env(safe-area-inset-bottom));
        overflow-y: auto;
    }

    #btn-upgrade,
    #btn-sell,
    .btn-deselect-tower {
        min-height: 44px;
    }

    #tutorial-panel {
        top: calc(52px + env(safe-area-inset-top));
        max-height: calc(100dvh - 125px - env(safe-area-inset-bottom));
        overflow-y: auto;
    }

    .difficulty-option,
    .meta-buy-btn {
        min-height: 44px;
    }

    .meta-upgrade-list {
        max-height: 44dvh;
    }
}

@media (max-height: 500px) and (orientation: landscape) {
    .screen-overlay {
        justify-content: flex-start;
        gap: 6px;
    }

    .screen-title {
        font-size: 1.8rem;
    }

    .screen-subtitle {
        margin-bottom: 4px;
    }

    .menu-btn {
        padding: 8px 24px;
    }

    #shop-bar {
        left: auto;
        right: max(8px, env(safe-area-inset-right));
        bottom: calc(62px + env(safe-area-inset-bottom));
        width: min(300px, 42vw);
        transform: none;
    }
}