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

body {
    background-color: #1d2021;
    color: #ebdbb2;
    font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
}

#game-container {
    position: relative;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
}

#gameCanvas {
    display: block;
    width: 100%;
    height: 100%;
}

#game-container.playing {
    cursor: none;
}

.overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background-color: #1d2021;
    z-index: 10;
    gap: 1.5rem;
}

.hidden {
    display: none !important;
}

h1 {
    font-size: 5rem;
    font-weight: 900;
    letter-spacing: 10px;
    color: #fb4934;
    text-shadow: 0 0 20px rgba(251, 73, 52, 0.3);
}

.subtitle {
    color: #a89984;
    font-size: 1.2rem;
    letter-spacing: 3px;
    margin-top: -0.5rem;
}

.controls-hint {
    color: #665c54;
    font-size: 1rem;
    letter-spacing: 1px;
    margin-top: 0.5rem;
}

.diff-group {
    display: flex;
    gap: 0.8rem;
}

.diff-btn {
    background-color: transparent;
    color: #a89984;
    border: 1px solid #504945;
    padding: 12px 28px;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.15s ease;
    letter-spacing: 1px;
}

.diff-btn:hover {
    border-color: #fe8019;
    color: #fe8019;
    box-shadow: none;
    transform: none;
}

.diff-btn.active {
    background-color: #fe8019;
    border-color: #fe8019;
    color: #1d2021;
}

button {
    background-color: #fb4934;
    color: #1d2021;
    border: none;
    padding: 16px 44px;
    font-size: 1.25rem;
    font-weight: 700;
    border-radius: 6px;
    cursor: pointer;
    transition:
        background-color 0.15s ease,
        transform 0.1s ease;
    letter-spacing: 1px;
}

button:hover {
    background-color: #cc241d;
    transform: translateY(-2px);
    box-shadow: none;
}

button:active {
    transform: translateY(0);
}

button.secondary {
    background-color: transparent;
    border: 2px solid #504945;
    color: #a89984;
}

button.secondary:hover {
    border-color: #a89984;
    color: #ebdbb2;
    background-color: rgba(235, 219, 178, 0.05);
}

.button-row {
    display: flex;
    gap: 1.5rem;
}

#hud {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: auto;
    padding: 24px 36px;
    display: flex;
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
    background: linear-gradient(to bottom, rgba(29, 32, 33, 0.7), transparent);
    pointer-events: none;
    z-index: 5;
    gap: 0;
}

#hud-left {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

#hp-bar-container {
    width: 280px;
    height: 20px;
    background-color: #282828;
    border-radius: 4px;
    overflow: hidden;
    border: 2px solid #504945;
}

#hp-bar {
    width: 100%;
    height: 100%;
    background-color: #b8bb26;
    transition:
        width 0.15s ease,
        background-color 0.3s ease;
}

#ammo-display {
    font-size: 1.2rem;
    font-weight: 700;
    letter-spacing: 2px;
    color: #a89984;
}

#score-display {
    font-size: 1.6rem;
    font-weight: 800;
    letter-spacing: 3px;
    color: #ebdbb2;
}

h2 {
    font-size: 4rem;
    font-weight: 900;
    letter-spacing: 8px;
    color: #fb4934;
    text-shadow: 0 0 15px rgba(251, 73, 52, 0.25);
}

#gameover-overlay p {
    color: #a89984;
    font-size: 1.4rem;
    letter-spacing: 1px;
}

#gameover-overlay p span {
    color: #ebdbb2;
    font-weight: 800;
}

#new-highscore-label {
    color: #fabd2f;
    font-weight: 800;
    font-size: 1.3rem;
    letter-spacing: 2px;
    animation: pulse 1.2s ease-in-out infinite alternate;
}

@keyframes pulse {
    from {
        opacity: 0.6;
    }

    to {
        opacity: 1;
    }
}